Geography of Japan

{{Short description|none}}  {{Infobox country geography | name = Japan | map = Satellite View of Japan 1999.jpg | continent = Asia | region = East Asia | coordinates = {{coord|36|N|138|E|type:country}} | area ranking = 62nd<ref>{{cite web |url=https://www.indexmundi.com/facts/indicators/AG.SRF.TOTL.K2/rankings |title=Countries ranked by Surface area (Sq. Km) |access-date=2022-03-24 |archive-date=2021-10-11 |archive-url=https://web.archive.org/web/20211011045953/https://www.indexmundi.com/facts/indicators/AG.SRF.TOTL.K2/rankings |url-status=live }}</ref> | km area = 377,973.89<ref name="Geospatial Information Authority of Japan 2022"/> | percent land = 87.93099 | km coastline = 29751 | exclusive economic zone = {{convert|4,470,000|km2|mi2|abbr=on}} | borders = None | geographic center = | highest point = Mount Fuji {{convert|3776|m|ft|abbr=on}}<ref name="CIA World Factbook">{{cite web |title=Japan |url=https://www.cia.gov/the-world-factbook/countries/japan/ |website=CIA World Factbook |access-date=11 November 2017 |archive-date=5 January 2021 |archive-url=https://web.archive.org/web/20210105105736/https://www.cia.gov/the-world-factbook/countries/japan/ |url-status=dead }}</ref> | lowest point = Hachirōgata {{convert|-4|m|ft|abbr=on}}<ref name="CIA World Factbook"/> | longest river = Shinano River {{convert|367|km|mi|abbr=on}}<ref>{{cite web |title=Shinano River |url=https://www.britannica.com/place/Shinano-River |website=Encyclopædia Britannica |access-date=11 November 2017 |archive-date=14 January 2021 |archive-url=https://web.archive.org/web/20210114170713/https://www.britannica.com/place/Shinano-River |url-status=live }}</ref> | largest lake = Lake Biwa {{convert|671|km2|sqmi|abbr=on}}<ref>{{cite web |title=Lake Biwa |url=https://www.britannica.com/place/Lake-Biwa |website=Encyclopædia Britannica |access-date=11 November 2017 |archive-date=21 March 2021 |archive-url=https://web.archive.org/web/20210321105731/https://www.britannica.com/place/Lake-Biwa |url-status=live }}</ref> | climate = Varied; tropical in the south to cool continental in the north, and mountainous areas being Subarctic or Alpine Tundra<ref name="CIA World Factbook"/> | terrain = Mostly rugged, volcanic, and mountainous<ref name="CIA World Factbook"/> | natural resources = Marine life and mineral resources in the territorial waters.<ref name="japan-seabed"/><ref name="World review of fisheries and aquaculture"/> Small deposits of coal, oil, iron, and minerals on land.<ref name="CIA World Factbook"/> | natural hazards = Volcanic eruptions, tsunamis, earthquakes, and typhoons<ref name="CIA World Factbook"/> | environmental issues = Air pollution; acidification of lakes and reservoirs; overfishing; deforestation<ref name="CIA World Factbook"/> }}

Japan is an archipelagic country comprising a stratovolcanic archipelago over {{convert|3000|km|mi|abbr=on}} along the Pacific coast of East Asia.<ref name="water-supply">{{cite web |title=Water Supply in Japan |format=website |url=https://www.mhlw.go.jp/english/policy/health/water_supply/1.html |archive-url=https://web.archive.org/web/20180126130519/https://www.mhlw.go.jp/english/policy/health/water_supply/1.html |archive-date = January 26, 2018 |publisher=Ministry of Health, Labour and Welfare | access-date = 26 September 2018}}</ref> It consists of 14,125 islands.<ref name="recount"/><ref name="離島">{{cite web |url=http://www.mlit.go.jp/crd/chirit/ritoutoha.html |title=離島とは(島の基礎知識) |publisher=Ministry of Land, Infrastructure, Transport and Tourism |language=ja |format=website|archive-url=https://web.archive.org/web/20071113053915/http://www.mlit.go.jp/crd/chirit/ritoutoha.html|archive-date=November 13, 2007|access-date=3 October 2018}}</ref> The five main islands are Hokkaido, Honshu, Kyushu, Shikoku, and Okinawa. The other 14,120 islands are classified as "remote islands" by the Japanese government.<ref name="recount" /><ref name="main-islands-japan">{{cite web |title=離島とは(島の基礎知識) (what is a remote island?) |publisher=Ministry of Land, Infrastructure, Transport and Tourism |url=http://www.mlit.go.jp/crd/chirit/ritoutoha.html |website=MLIT (Ministry of Land, Infrastructure, Transport and Tourism) |date=22 August 2015 |access-date= 9 August 2019 |language=ja |format=website |quote=MILT classification 6,852 islands (main islands: 5 islands, remote islands: 6,847 islands) |archive-url=https://web.archive.org/web/20071113053915/http://www.mlit.go.jp/crd/chirit/ritoutoha.html |archive-date=2007-11-13}}</ref> The Ryukyu Islands and Nanpō Islands are south and east of the main islands.

The territory covers {{convert|377,973.89|km2|sqmi|abbr=on}}.<ref name="Geospatial Information Authority of Japan 2022"/> It is the fourth-largest island country in the world and the largest island country in East Asia.<ref name="world-atlas">{{cite web |url=https://www.worldatlas.com/articles/which-are-the-island-countries-of-the-world.html |title=Island Countries Of The World |publisher=WorldAtlas.com |access-date=2019-08-10 |archive-url=https://web.archive.org/web/20171207094959/http://www.worldatlas.com/articles/which-are-the-island-countries-of-the-world.html | archive-date=2017-12-07}}</ref> The country has the 6th longest coastline at {{convert|29751 |km|mi|abbr=on}} and the 8th largest Exclusive Economic Zone of {{convert|4470000|km2|sqmi|abbr=on}} in the world.<ref name="kaiho">{{cite web |url=http://www1.kaiho.mlit.go.jp/JODC/ryokai/ryokai_setsuzoku.html |title=日本の領海等概念図 |publisher=海上保安庁海洋情報部| access-date=12 August 2018| archive-url=https://web.archive.org/web/20180812151410/http://www1.kaiho.mlit.go.jp/JODC/ryokai/ryokai_setsuzoku.html| archive-date=August 12, 2018}}</ref>

The terrain is mostly rugged and mountainous, with 66% forest.<ref name="worldbank"/> The population is clustered in urban areas along the coast, plains, and valleys.<ref name="autogenerated1">{{cite web |title=地形分類 |url=http://www.gsi.go.jp/atlas/archive/j-atlas-d_j_02.pdf |publisher=Geospatial Information Authority of Japan |access-date=2015-10-14 |archive-date=2016-03-05 |archive-url=https://web.archive.org/web/20160305031643/http://www.gsi.go.jp/atlas/archive/j-atlas-d_j_02.pdf |url-status=live }}</ref> Japan is located in the northwestern Ring of Fire on multiple tectonic plates.<ref name="Barnes"/> East of the Japanese archipelago are three oceanic trenches. The Japan Trench is created as the oceanic Pacific Plate subducts beneath the continental Okhotsk Plate.<ref name="revel">{{Cite journal |last1=Sella |first1=Giovanni F. |last2=Dixon |first2=Timothy H. |last3=Mao |first3=Ailin |date=2002 |title=REVEL: A model for Recent plate velocities from space geodesy |url=https://scholarcommons.usf.edu/geo_facpub/468 |journal=Journal of Geophysical Research: Solid Earth |volume=107 |issue=B4 |pages=ETG 11–1–ETG 11–30 |bibcode=2002JGRB..107.2081S |doi=10.1029/2000jb000033 |issn=0148-0227 |access-date=2019-07-01 |archive-date=2020-06-07 |archive-url=https://web.archive.org/web/20200607135855/https://scholarcommons.usf.edu/geo_facpub/468/ |url-status=live |url-access=subscription }}</ref> The continuous subduction process causes frequent earthquakes, tsunamis, and stratovolcanoes.<ref name="volcanoes-japan"/> The islands are also affected by typhoons. The subduction plates have pulled the Japanese archipelago eastward, created the Sea of Japan, and separated it from the Asian continent by back-arc spreading 15 million years ago.<ref name="Barnes"/>

The climate varies from humid continental in the north to humid subtropical and tropical rainforests in the south. These differences in climate and landscape have allowed the development of a diverse flora and fauna, with some rare endemic species, especially in the Ogasawara Islands.

Japan extends from 20° to 45° north latitude (Okinotorishima to Benten-jima) and from 122° to 153° east longitude (Yonaguni to Minami Torishima).<ref name="geohack"/> Japan is surrounded by seas. To the north, the Sea of Okhotsk separates it from the Russian Far East; to the west, the Sea of Japan separates it from the Korean Peninsula; to the southwest, the East China Sea separates the Ryukyu Islands from China and Taiwan; to the east is the Pacific Ocean.

The Japanese archipelago is over {{convert|3000|km|mi|abbr=on}} long in a north-to-southwardly direction from the Sea of Okhotsk to the Philippine Sea in the Pacific Ocean.<ref name="water-supply"/> It is narrow, and no point in Japan is more than {{convert|150|km|mi|abbr=on}} from the sea. In 2023, a government recount of the islands with digital maps increased the total from 6,852 to 14,125 islands.<ref name="recount">{{cite web |title=Recount with digital map leads to doubling of listed Japanese islands |website=Japan Times |url=https://www.japantimes.co.jp/news/2023/02/15/national/japanese-islands-recount/ |date=Feb 15, 2023 |archive-url=https://archive.today/20230215042328/https://www.japantimes.co.jp/news/2023/02/15/national/japanese-islands-recount/ |archive-date=February 15, 2023}}</ref> The five main islands are (from north to south) Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa. Three of the four major islands (Honshu, Kyushu, and Shikoku) are separated by narrow straits of the Seto Inland Sea and form a natural entity. The smaller remote islands include the Bonin Islands, Daitō Islands, Minami-Tori-shima, Okinotorishima, the Ryukyu Islands, the Volcano Islands, Nansei Islands, and the Nanpō Islands, as well as numerous islets, of which 430 are inhabited. The Senkaku Islands are administered by Japan but disputed by China. This excludes the disputed Northern Territories (Kuril Islands) and Liancourt Rocks. In total, as of 2021, Japan's territory is {{convert|377,973.89|km2|sqmi|abbr=on}}, of which {{convert|364546.41|km2|sqmi|abbr=on}} is land and {{convert|13430|km2|sqmi|abbr=on}} is water.<ref name="Geospatial Information Authority of Japan 2022"/> It is the largest island country in East Asia and the fourth largest island country in the world.<ref name="world-atlas"/>

Because of Japan's many far-flung outlying islands and long coastline, the country has extensive marine life and mineral resources in the ocean. The Exclusive Economic Zone of Japan covers {{convert|4470000|km2|sqmi|abbr=on}} and is the 8th largest in the world. It is more than 11 times the land area of the country.<ref name="kaiho"/> The Exclusive Economic Zone stretches from the baseline out to {{Convert|200|nmi|km|abbr=}} from its coast. Its territorial sea is {{convert|12|nmi|1|abbr=on}}, but between {{convert|3|and|12|nmi|1|abbr=on}} in the international straits—La Pérouse (or Sōya Strait), Tsugaru Strait, Ōsumi, and Tsushima Strait.

Japan has a population of 126 million as of 2019.<ref name="SBJ-Population-June-2019"/> It is the 11th most populous country in the world and the second most populous island country.<ref name="world-atlas"/> 81% of the population lives on Honshu, 10% on Kyushu, 4.2% on Hokkaido, 3% on Shikoku, 1.1% in Okinawa Prefecture, and 0.7% on other Japanese islands such as the Nanpō Islands.

==Map of Japan== thumb|upright=1.20|Regions and prefectures of Japan {{main|Regions of Japan}} Japan is formally divided into eight regions, from northeast (Hokkaidō) to southwest (Ryukyu Islands):<ref>{{Cite web |url=http://www.japan-guide.com/list/e1001.html |title=Regions of Japan on japan-guide.com |access-date=2018-09-26 |archive-date=2006-07-10 |archive-url=https://web.archive.org/web/20060710153046/http://www.japan-guide.com/list/e1001.html |url-status=live }}</ref> * Hokkaido * Tōhoku region * Kantō region * Chūbu region * Kansai (or Kinki) region * Chūgoku region * Shikoku * Kyūshū

Each region contains several prefectures, except the Hokkaido region, which comprises only Hokkaido Prefecture.

The regions are not official administrative units but have been traditionally used as the regional division of Japan in a number of contexts. For example, maps and geography textbooks divide Japan into the eight regions; weather reports usually give the weather by region; and many businesses and institutions use their home region as part of their name (Kinki Nippon Railway, Chūgoku Bank, Tohoku University, etc.). While Japan has eight High Courts, their jurisdictions do not correspond with the eight regions.

==Composition, topography and geography== thumb|upright=1.2|A topographic map of Japan About 73% of Japan is mountainous,<ref>{{Cite web |title=Statistics Bureau Home Page/Statistical Handbook of Japan 2022 |url=https://www.stat.go.jp/english/data/handbook/c0117.html |access-date=2023-04-14 |website=www.stat.go.jp |archive-date=2021-10-23 |archive-url=https://web.archive.org/web/20211023074041/http://www.stat.go.jp/english/data/handbook/c0117.html |url-status=live }}</ref> with a mountain range running through each of the main islands. Japan's highest mountain is Mount Fuji, with an elevation of {{convert|3776|m|ft|0|abbr=on}}. Japan's forest cover rate is 68.55% since the mountains are heavily forested. The only other developed nations with such a high forest cover percentage are Finland and Sweden.<ref name="worldbank">{{cite web |title=Forest area |url=http://data.worldbank.org/indicator/AG.LND.FRST.ZS?order=wbapi_data_value_2013+wbapi_data_value+wbapi_data_value-last&sort=desc |publisher=The World Bank Group |access-date=2015-10-11 |archive-date=2015-10-16 |archive-url=https://web.archive.org/web/20151016000406/http://data.worldbank.org/indicator/AG.LND.FRST.ZS?order=wbapi_data_value_2013+wbapi_data_value+wbapi_data_value-last&sort=desc |url-status=live }}</ref>

Since there is little level ground, many hills and mountainsides at lower elevations around towns and cities are often cultivated. As Japan is situated in a volcanic zone along the Pacific deeps, frequent low-intensity earth tremors and occasional volcanic activity are felt throughout the islands. Destructive earthquakes occur several times a century. Hot springs are numerous and have been exploited by the leisure industry.

The Geospatial Information Authority of Japan measures Japan's territory annually in order to continuously grasp the state of the national land. As of July 1, 2021, Japan's territory is {{convert|377,973.89|km2|sqmi}}. It increases in area due to volcanic eruptions such as Nishinoshima (西之島), the natural expansion of the islands, and land reclamation.<ref name="Geospatial Information Authority of Japan 2022">{{cite web |title=【お知らせ】令和3年全国都道府県市区町村別面積調（7月1日時点）, Reiwa 3rd year National area of each prefecture municipality (as of July 1) |url=https://www.gsi.go.jp/KOKUJYOHO/MENCHO-title.htm |publisher=Geospatial Information Authority of Japan |access-date=October 15, 2021 |language=ja |date=23 March 2022 |archive-url=https://web.archive.org/web/20220409070834/https://www.gsi.go.jp/KOKUJYOHO/MENCHO-title.htm |archive-date=April 9, 2022}}</ref>

This table shows land use in 2002.<ref name="mlit-2011">{{cite web |url=http://tochi.mlit.go.jp/wp-content/uploads/2011/02/16-02.pdf |title=土地総合情報ライブラリー平成16年土地の動向に関する年次報告第2章土地に関する動向 |publisher=国土交通省 |language=ja|access-date=2007-02-17|url-status=live|archive-url=https://web.archive.org/web/20130120195343/http://tochi.mlit.go.jp/wp-content/uploads/2011/02/16-02.pdf|archive-date=2013-01-20}}</ref>

{| class="wikitable sortable" style="margin:auto; width:50%;" |- ! style="width:14%;" class="unsortable"| Forest ! style="width:14%;" class="unsortable"| Agricultural land ! style="width:14%;" class="unsortable"| Residential area ! style="width:14%;" class="unsortable"| Water surface, rivers, waterways ! style="width:14%;" class="unsortable"| Roads ! style="width:14%;" class="unsortable"| Wilderness ! style="width:16%;" class="unsortable"| Other |- class="vcard" style="text-align:center;" | 66.4% || 12.8% || 4.8% || 3.6% || 3.4% || 0.7% || 8.3% |- class="vcard" style="text-align:center;" | {{convert|251,000|km2|sqmi|abbr=on}} || {{convert|48,400|km2|sqmi|abbr=on}} || {{convert|18,100|km2|sqmi|abbr=on}} || {{convert|13,500|km2|sqmi|abbr=on}} || {{convert|13,000|km2|sqmi|abbr=on}} || {{convert|2,600|km2|sqmi|abbr=on}} || {{convert|31,300|km2|sqmi|abbr=on}} |}

===Location=== The Japanese archipelago is relatively far away from the Asian continent. Kyushu is closest to the southernmost point of the Korean peninsula, with a distance of {{convert|190|km|mi|abbr=on}}, which is almost six times farther away than from England to France across the English Channel. Thus, historically, Kyushu was the gateway between Asia and Japan. China is separated by {{convert|800|km|mi|abbr=on}} of sea from Japan's big main islands. Hokkaido is near Sakhalin, which was occupied by Japan from 1905 to 1945. Most of the population lives on the Pacific coast of Honshū. The west coast facing the Sea of Japan is less densely populated.<ref name="jpn-places"/>

The Japanese archipelago has been difficult to reach since ancient history. During the Paleolithic period around 20,000 BCE, at the height of the Last Glacial Maximum, there was a land bridge between Hokkaido and Sakhalin that linked Japan with the Asian continent. The land bridge disappeared when sea levels rose in the Jōmon period around 10,000 BCE.<ref name=Japan>{{cite book |last1=Campbell |first1=Allen |last2=Nobel |first2=David S |title=Japan: An Illustrated Encyclopedia |publisher=Kodansha |date=1993 |page=1186 |isbn=406205938X}}</ref>

Japan's remote location, surrounded by vast seas, rugged, mountainous terrain, and steep rivers, makes it secure against invaders and uncontrolled migration from the Asian continent. The Japanese can close their civilization with an isolationist foreign policy. During the Edo period, the Tokugawa Shogunate enforced the Sakoku policy, which prohibited most foreign contact and trade from 1641 to 1853.<ref>Ronald P. Toby, ''State and Diplomacy in Early Modern Japan: Asia in the Development of the Tokugawa Bakufu'', Stanford, California: Stanford University Press, (1984) 1991.</ref> In modern times, the inflow of people is managed via seaports and airports. Thus, Japan is fairly insulated from continental issues.

Throughout history, Japan has never been fully invaded or colonized by other countries. The Mongols tried to invade Japan twice and failed in 1274 and 1281. Japan capitulated only once after nuclear attacks in World War II. At the time, Japan did not have nuclear technology. The insular geography is a major factor in the isolationist, semi-open, and expansionist periods of Japanese history.

===Mountains and volcanoes=== {{main|List of mountains and hills of Japan by height}}

The mountainous islands of the Japanese archipelago form a crescent off the eastern coast of Asia.<ref name=loc>{{citation-attribution|1={{Cite book |url=https://www.loc.gov/item/91029874/ |title=Japan: a country study |series=Area handbook series |date=1992 |publisher=Federal Research Division, Library of Congress |isbn=0-8444-0731-3 |editor-last=Dolan |editor-first=Ronald E. |edition=5th |location=Washington, D.C. |pages=72–84 |oclc=24247433 |access-date=2020-11-02 |archive-date=2021-07-29 |archive-url=https://web.archive.org/web/20210729190534/https://www.loc.gov/item/91029874/ |url-status=live }}|editor-last2=Worden|editor-first2=Robert L.}}</ref> They are separated from the continent by the Sea of Japan, which serves as a protective barrier. Japan has 108 active volcanoes (10% of the world's active volcanoes) because of active plate tectonics in the Ring of Fire.<ref name="volcanoes-japan"/>

Around 15 million years ago, the volcanic shoreline of the Asian continent was pushed out into a series of volcanic island arcs.<ref name="Barnes"/> This created the "back-arc basins" known as the Sea of Japan and Sea of Okhotsk with the formal shaping of the Japanese archipelago.<ref name="Barnes"/> The archipelago also has summits on mountain ridges that were uplifted near the outer edge of the continental shelf.<ref name=loc/> About 73 percent of Japan's area is mountainous, and scattered plains and intermontane basins (in which the population is concentrated) cover only about 27 percent.<ref name=loc/> A long chain of mountains runs down the middle of the archipelago, dividing it into two halves: the "face", facing the Pacific Ocean, and the "back", toward the Sea of Japan.<ref name=loc/> On the Pacific side are steep mountains 1,500 to 3,000 meters high, with deep valleys and gorges.<ref name=loc/>

Central Japan is marked by the convergence of the three mountain chains—the Hida, Kiso, and Akaishi mountains—that form the Japanese Alps (''Nihon Arupusu''), several of whose peaks are higher than {{convert|3000|m|ft}}.<ref name=loc/> The highest point in the Japanese Alps is Mount Kita at {{convert|3193|m|ft}}.<ref name=loc/> The highest point in the country is Mount Fuji (Fujisan, also erroneously called Fujiyama), a volcano dormant since 1707 that rises to {{convert|3776|m|ft|abbr=on}} above sea level in Shizuoka Prefecture.<ref name=loc/> On the Sea of Japan side are plateaus and low mountain districts, with altitudes of 500 to 1,500 meters.<ref name=loc/>

===Plains=== thumb|220px|Map of the Kantō Plain There are three major plains in central Honshū. The largest is the Kantō Plain, which covers {{convert|17000|km2|mi2|abbr=on}} in the Kantō region. The capital Tokyo and the largest metropolitan population are located there. The second largest plain in Honshū is the Nōbi Plain ({{convert|1800|km2|mi2|abbr=on}}), with the third-most-populous urban area being Nagoya. The third-largest plain in Honshū is the Osaka Plain, which covers {{convert|1600|km2|mi2|abbr=on}} in the Kinki region. It features the second-largest urban area of Osaka (part of the Keihanshin metropolitan area). Osaka and Nagoya extend inland from their bays until they reach steep mountains. The Osaka Plain is connected with Kyoto and Nara. Kyoto is located in the Yamashiro Basin ({{convert|827.9|km2|mi2|abbr=on}}) and Nara is in the Nara Basin ({{convert|300|km2|mi2|abbr=on}}).

The Kantō Plain, Osaka Plain, and Nōbi Plain are the most important economic, political, and cultural areas of Japan. These plains had the largest agricultural production and large bays with ports for fishing and trade. This made them the largest population centers. Kyoto and Nara are the ancient capitals and cultural heart of Japan. The Kantō Plain became Japan's center of power because it is the largest plain with a central location, and historically, it had the most agricultural production that could be taxed. The Tokugawa Shogunate established a ''bakufu'' in Edo in 1603.<ref>Gordon, Andrew. (2003). ''A Modern History of Japan from Tokugawa Times to the Present'', p. 23.</ref> This evolved into the capital of Tokyo by 1868.

Hokkaido has multiple plains, such as the Ishikari Plain ({{convert|3800|km2|mi2|abbr=on}}), Tokachi Plain ({{convert|3600|km2|mi2|abbr=on}}), the Kushiro Plain, the largest wetland in Japan ({{convert|2510|km2|mi2|abbr=on}}), and the Sarobetsu Plain ({{convert|200|km2|mi2|abbr=on}}). There are many farms that produce a plethora of agricultural products. The average farm size in Hokkaido was 26 hectares per farmer in 2013. That is nearly 11 times larger than the national average of 2.4 hectares. This made Hokkaido the most agriculturally rich prefecture in Japan.<ref name="Agriculture Hokkaido">{{Cite news |title=Trend toward stronger agriculture seen in Hokkaido |url=https://asia.nikkei.com/Business/Biotechnology/Trend-toward-stronger-agriculture-seen-in-Hokkaido/ |work=The Nikkei |date=5 January 2015 |access-date=7 April 2019 |archive-url=https://web.archive.org/web/20190407200056/https://asia.nikkei.com/Business/Biotechnology/Trend-toward-stronger-agriculture-seen-in-Hokkaido/ |archive-date=7 April 2019 |url-status=live |df=dmy}}</ref> Nearly one-fourth of Japan's arable land and 22% of Japan's forests are in Hokkaido.<ref name="business-env">{{cite web |url=http://www.pref.hokkaido.jp/keizai/kz-bkkry/env/env-e.html |title=Hokkaido's Business Environment |publisher=Trade and Economic Exchange Group, Commerce and Economic Exchange Division, Department of Economic Affairs, Hokkaido Government|access-date=2008-12-05|archive-url=https://web.archive.org/web/20100721020826/http://www.pref.hokkaido.jp/keizai/kz-bkkry/env/env-e.html|archive-date=2010-07-21}}</ref>

Another important plain is the Sendai Plain around the city of Sendai in northeastern Honshū.<ref name=loc/> Many of these plains are along the coast, and their areas have been increased by land reclamation throughout recorded history.<ref name=loc/>

===Rivers=== [[File:NiigataCityOpenData machinami004.jpg|thumb|Shinano River in Niigata City]] {{main|List of rivers of Japan}}

Rivers are generally steep and swift, and few are suitable for navigation except in their lower reaches. Although most rivers are less than {{convert|300|km|mi|abbr=on}} in length, their rapid flow from the mountains is what provides hydroelectric power.<ref name=loc/> Seasonal variations in flow have led to the extensive development of flood control measures.<ref name=loc/> The longest, the Shinano River, which winds through Nagano Prefecture to Niigata Prefecture and flows into the Sea of Japan, is {{convert|367|km|mi|abbr=on}} long.<ref name=loc/><ref name="longest-rivers"/>

These are the 10 longest rivers of Japan.<ref name="longest-rivers">{{cite web |title=Longest Rivers In Japan |format=website |url=https://www.worldatlas.com/articles/the-longest-rivers-in-japan.html |archive-url=https://web.archive.org/web/20181117105043/https://www.worldatlas.com/articles/the-longest-rivers-in-japan.html |archive-date = November 17, 2018 |publisher=WorldAtlas.com | access-date = 9 February 2020}}</ref>

{| class="wikitable sortable" ! class="unsortable"|Rank !Name !Region !Prefecture !Length (km) |- |1 |Shinano |Hokuriku |Nagano, Niigata |367 |- |2 |Tone |Kantō |Saitama, Chiba, Ibaraki, Tochigi, Gunma |322 |- |3 |Ishikari |Hokkaido |Hokkaido |268 |- |4 |Teshio |Hokkaido |Hokkaido |256 |- |5 |Kitakami |Tōhoku |Iwate, Miyagi |249 |- |6 |Abukuma |Tōhoku |Fukushima, Miyagi |239 |- |7 |Mogami |Tōhoku |Yamagata |229 |- |8 |Tenryu |Chūbu |Nagano, Aichi, Shizuoka |212 |- |9 |Agano |Hokuriku |Niigata |210 |- |10 |Shimanto |Shikoku |Kōchi |196 |}

===Lakes and coasts=== [[File:20091015琵琶湖.jpg|thumb|Aerial view of Lake Biwa]] {{main|List of lakes of Japan}}

The largest freshwater lake is Lake Biwa ({{convert|670.3|km2|sqmi|abbr=on}}), northeast of Kyoto in Shiga Prefecture.<ref name=Tabata2016>{{Cite journal |doi=10.1002/ece3.2070 |title=Phylogeny and historical demography of endemic fishes in Lake Biwa: The ancient lake as a promoter of evolution and diversification of freshwater fishes in western Japan |year=2016 |last1=Tabata |first1=Ryoichi |last2=Kakioka |first2=Ryo |last3=Tominaga |first3=Koji |last4=Komiya |first4=Takefumi |last5=Watanabe |first5=Katsutoshi |journal=Ecology and Evolution |volume=6 |issue=8 |pages=2601–2623 |pmid=27066244 |pmc=4798153|bibcode=2016EcoEv...6.2601T }}</ref> Lake Biwa is an ancient lake and is estimated to be the 13th oldest lake in the world, dating to at least 4 million years ago.<ref name="marine-rutgers">{{cite web |title=Ancient lakes of the world |url=https://marine.rutgers.edu/~cfree/ancient-lakes-of-the-world/|archive-url=https://web.archive.org/web/20200209063201/https://marine.rutgers.edu/~cfree/ancient-lakes-of-the-world/|archive-date=February 9, 2020|access-date=20 January 2020 |publisher=Christopher M. Free |format=website}}</ref><ref name=Tabata2016/> It has consistently carried water for millions of years. Lake Biwa was created by plate tectonics in an active rift zone. This created a very deep lake with a maximum depth of {{convert|104|m|feet|abbr=on}}. Thus, it is not naturally filled with sediment. Over the course of millions of years, a diverse ecosystem evolved in the lake. It has more than 1,000 species and subspecies. There are 46 native fish species and subspecies,<ref name=fish>Kawanabe, H.; Nishino, M.; and Maehata, M., editors (2012). ''Lake Biwa: Interactions between Nature and People.'' pp 119-120. {{ISBN|978-94-007-1783-1}}</ref> including 11 species and 5 subspecies that are endemic or near-endemic.<ref name=Tabata2016/> Approximately 5,000 water birds visit the lake each year.

The following are the 10 largest lakes of Japan.<ref name="GSI-20172">国土地理院平成29年全国都道府県市区町村別面積調 [http://www.gsi.go.jp/KOKUJYOHO/MENCHO/201710/f1_kosho.pdf 付1 湖沼面積（平成29年10月1日版）] {{Webarchive|url=https://web.archive.org/web/20180210003158/http://www.gsi.go.jp/KOKUJYOHO/MENCHO/201710/f1_kosho.pdf|date=2018-02-10}} 2018年2月10日閲覧。</ref>

{| class="wikitable sortable" |- ! class="unsortable"|Rank ! Name ! Region ! Prefecture ! class="unsortable"|Municipalities !Type ! class="unsortable"|Water salinity ! Area (km2) ! Max Depth (m) ! Altitude (m) ! Volume (km3) |- | 1 || Biwa || Kansai || Shiga || Ōtsu, Kusatsu, Higashi-Ōmi, Hikone Nagahama, Moriyama, Ōmi-Hachiman Takashima, Yasu, Maibara |Ancient lake, tectonic, freshwater|| Fresh || 670.3 || 103.8 || 85|| 27.5 |- | 2 || Kasumigaura || Kantō || Ibaraki || Tsuchiura, Ishioka, Omitama, Inashiki Ami, Kasumigaura, Namegata, Itako, Miho |Warm monomictic lake|| Fresh || 167.6 || 7.10 || 0 || 0.85 |- | 3 || Saroma || Hokkaido || Okhotsk || Kitami, Saroma, Yūbetsu |Mesotrophic|| Brackish || 151.9 || 19.6 || 0 || 1.3 |- | 4 || Inawashiro || Tōhoku || Fukushima || Kōriyama, Aizu-Wakamatsu, Inawashiro |Tectonic lake|| Fresh || 103.3 || 94.6 || 514 || 5.40 |- | 5 || Nakaumi || San'in || Shimane Tottori || Matsue, Yonago, Yasugi, Sakaiminato |Brackish|| Brackish || 86.2 || 17.1 || 0 || 0.47 |- | 6 || Kussharo || Hokkaido || Kushiro || Teshikaga |Acidotrophic crater lake|| Fresh || 79.3 || 117.5 || 121 || 2.25 |- | 7 || Shinji || San'in || Shimane || Matsue, Izumo |Brackish|| Brackish || 79.1 || 6.0 || 0 || 0.34 |- | 8 || Shikotsu || Hokkaido || Ishikari || Chitose |Crater lake|| Fresh || 78.4 || 360.1 || 247 || 20.9 |- | 9 || Tōya || Hokkaido || Iburi || Tōyako, Sōbetsu |Oligotrophic crater lake|| Fresh || 70.7 || 179.9 || 84 || 8.19 |- | 10 || Hamana || Tōkai || Shizuoka || Hamamatsu, Kosai |Brackish lagoon|| Brackish || 65.0 || 13.1 || 0 || 0.35 |}

[[File:Seto_Inland_Sea.jpg|thumb|Seto Inland Sea]] Extensive coastal shipping, especially around the Seto Inland Sea, compensates for the lack of navigable rivers.<ref name=loc/> The Pacific coastline south of Tokyo is characterized by long, narrow, gradually shallowing inlets produced by sedimentation, which has created many natural harbors.<ref name=loc/> The Pacific coastline north of Tokyo, the coast of Hokkaido, and the Sea of Japan coast are generally unindented, with few natural harbors.<ref name=loc/>

A recent global remote sensing analysis suggested that there were 765 km2 of tidal flats in Japan, making it the 35th-ranked country in terms of tidal flat extent.<ref>{{cite journal |last1=Murray |first1=N.J. |last2=Phinn |first2=S.R. |last3=DeWitt |first3=M. |last4=Ferrari |first4=R. |last5=Johnston |first5=R. |last6=Lyons |first6=M.B. |last7=Clinton |first7=N. |last8=Thau |first8=D. |last9=Fuller |first9=R.A. |title=The global distribution and trajectory of tidal flats |journal=Nature |date=2019 |volume=565 |issue=7738 |pages=222–225 |doi=10.1038/s41586-018-0805-8 |pmid=30568300 |s2cid=56481043 |url=https://www.nature.com/articles/s41586-018-0805-8 |access-date=2021-08-03 |archive-date=2021-11-24 |archive-url=https://web.archive.org/web/20211124213205/https://www.nature.com/articles/s41586-018-0805-8 |url-status=live |url-access=subscription }}</ref>

===Land reclamation=== [[File:151229_Kobe_Port_Japan02bs.jpg|thumb|Kobe Airport in Osaka Bay]] The Japanese archipelago has been transformed by humans into a sort of continuous land, in which the four main islands are entirely reachable and passable by rail and road transportation thanks to the construction of huge bridges and tunnels that connect each other and various islands.<ref>{{cite book |title=Il mondo come sistema |author=E. Fedrizzi and S. Ferri |year=2000 |publisher=Minerva Italica |isbn=88-298-1989-1}}</ref>

Approximately 0.5% of Japan's total area is reclaimed land (''umetatechi'').<ref name="reclaimed-land"/> It began in the 12th century.<ref name="reclaimed-land"/> Land was reclaimed from the sea and from river deltas by building dikes, drainage, and rice paddies on terraces carved into mountainsides.<ref name=loc/> The majority of land reclamation projects occurred after World War II, during the Japanese economic miracle. Reclamation of 80% to 90% of all the tidal flatland was done. Large land reclamation projects with landfills were done in coastal areas for maritime and industrial factories, such as Higashi Ogishima in Kawasaki, Osaka Bay, and Nagasaki Airport. Port Island, Rokkō Island, and Kobe Airport were built in Kobe. Late 20th and early 21st century projects include artificial islands such as Chubu Centrair International Airport in Ise Bay, Kansai International Airport in the middle of Osaka Bay, Yokohama Hakkeijima Sea Paradise, and Wakayama Marina City.<ref name="reclaimed-land">{{cite web |url=http://japanpropertycentral.com/real-estate-faq/reclaimed-land-in-japan/ |title=Reclaimed Land in Japan |date=13 November 2011 |publisher=Japan Property Central |access-date=2018-09-26 |url-status=live |archive-url=https://web.archive.org/web/20180226211747/http://japanpropertycentral.com/real-estate-faq/reclaimed-land-in-japan/ |archive-date=2018-02-26}}</ref> The village of Ōgata in Akita was established on land reclaimed from Lake Hachirōgata (Japan's second largest lake at the time) starting in 1957. By 1977, the amount of land reclaimed totaled {{convert|172.03|km2}}.<ref>{{cite web |url=http://www.ogata.or.jp/english/history.html |title=The History of Ogata-Mura {{pipe}} Ogata-mura |publisher=Ogata.or.jp |access-date=2014-04-17 |url-status=dead |archive-url=https://web.archive.org/web/20150924055244/http://www.ogata.or.jp/english/history.html |archive-date=2015-09-24}}</ref>

Examples of land reclamation in Japan include: * Kyogashima, Kobe – the first human-made island built by Taira no Kiyomori in 1173<ref name="reclaimed-land"/> * The Hibiya Inlet, Tokyo – the first large-scale reclamation project started in 1592<ref name="reclaimed-land"/> * Dejima, Nagasaki – built during Japan's national isolation period in 1634. It was the sole trading post in Japan during the Sakoku period and was originally inhabited by Portuguese and then Dutch traders.<ref name="reclaimed-land"/> * Tokyo Bay, Japan – {{convert|249|km2}}<ref>{{cite web |title=Japan Fact Sheet |publisher=Japan Reference |url=http://www.jref.com/society/japan_fact_sheet.shtml |access-date=2007-03-23 |archive-date=2007-02-27 |archive-url=https://web.archive.org/web/20070227234242/http://www.jref.com/society/japan_fact_sheet.shtml |url-status=live }}</ref> artificial island (2007) ** This includes the entirety of Odaiba, a series of island forts constructed to protect Tokyo from sea attacks (1853).<ref name="reclaimed-land"/> * Kobe, Japan – {{convert|23|km2}} (1995).<ref name="reclaimed-land"/> * Isahaya Bay in the Ariake Sea – approximately {{convert|35|km2}} is reclaimed with tide embankment and sluice gates (2018). * Yumeshima, Osaka – {{convert|390|ha}} artificial island (2025) * Central Breakwater – {{convert|989|ha}} Much reclaimed land is made up of landfill waste materials, dredged earth, sand, sediment, sludge, and soil removed from construction sites. It is used to build human-made islands in harbors and embankments in inland areas.<ref name="reclaimed-land"/> On November 8, 2011, Tokyo City began accepting rubble and waste from the 2011 Tōhoku earthquake and tsunami region. This rubble was processed, and when it had the appropriate radiation levels, it was used as a landfill to build new artificial islands in Tokyo Bay. Yamashita Park in Yokohama City was made with rubble from the great Kantō earthquake in 1923.<ref name="reclaimed-land"/>

There is a risk of contamination on artificial islands with landfills and reclaimed land if there was industry that spilled toxic chemicals into the ground. For example, the artificial island of Toyosu was once occupied by a Tokyo gas factory. Toxic substances were discovered in the soil and groundwater at Toyosu. The Tokyo Metropolitan Government spent an additional 3.8 billion yen ($33.5 million) to pump out groundwater by digging hundreds of wells.<ref name="historic-tsukiji">{{cite news |url=https://widerimage.reuters.com/story/as-historic-tsukiji-market-closes-fishmongers-mourn |access-date=October 4, 2018 |title=As Tokyo's historic Tsukiji market closes, fishmongers mourn |first=Issei |last=Kato |date=29 September 2018 |work=Reuters |url-status=live |archive-url=https://web.archive.org/web/20181003005402/https://widerimage.reuters.com/story/as-historic-tsukiji-market-closes-fishmongers-mourn |archive-date=October 3, 2018}}</ref> In June 2017, plans to move the Tsukiji fish market were restarted<ref>{{cite news |last1=Osumi |first1=Magdalena |last2=Aoki |first2=Mizuho |title=Koike announces Tsukiji relocation, plans to retain its 'cultural legacy' |url=http://www.japantimes.co.jp/news/2017/06/20/national/tokyo-governor-announces-tsukiji-fish-markets-relocation-possible-plan-return-five-years/ |access-date=24 July 2017 |work=Japan Times |date=20 June 2017 |archive-date=13 August 2023 |archive-url=https://web.archive.org/web/20230813185501/https://www.japantimes.co.jp/news/2017/06/20/national/tokyo-governor-announces-tsukiji-fish-markets-relocation-possible-plan-return-five-years/ |url-status=live }}</ref> but delayed from July to the autumn of 2018.<ref>{{cite news |title=Tsukiji market relocation to Toyosu delayed till autumn 2018 |url=https://mainichi.jp/english/articles/20170721/p2a/00m/0na/016000c |access-date=24 July 2017 |work=The Mainichi |date=21 July 2017 |archive-date=12 August 2023 |archive-url=https://web.archive.org/web/20230812142028/https://mainichi.jp/english/articles/20170721/p2a/00m/0na/016000c |url-status=live }}</ref> After the new site was declared safe following a cleanup operation, Toyosu Market was opened.<ref>{{cite news |url=https://www.theguardian.com/world/2018/aug/26/tokyo-tsukiji-fish-market-moves |title=Tokyo fears losing a part of its soul as world's biggest fish market moves |first=Justin |last=McCurry |date=26 August 2018 |work=The Guardian |access-date=17 October 2018 |archive-date=12 August 2023 |archive-url=https://web.archive.org/web/20230812140613/https://www.theguardian.com/world/2018/aug/26/tokyo-tsukiji-fish-market-moves |url-status=live }}</ref>

==Oceanography and seabed of Japan== thumb|upright=1.3| Relief map of the land and the seabed of Japan. It shows the surface and underwater terrain of the Japanese archipelago. Japan's sea territory is {{convert|4,470,000|km2|mi2|abbr=on}}.<ref name="kaiho"/> Japan ranks fourth with its exclusive economic zone ocean water volume from 0 to {{convert|2000|m|ft|abbr=on}} depth. Japan ranks fifth with a sea volume of 2,000–3,000 meters, fourth with 3,000–4,000 meters, third with 4,000–5,000 meters, and first with a volume of 5,000 to over 6,000 meters. The relief map of the Japanese archipelago shows that 50% of Japan's sea territory has an ocean volume between 0 and {{convert|4000|m|ft|abbr=on}} deep. The other 50% has a depth of {{convert|4000|m|ft|abbr=on}} to over {{convert|6000|m|ft|abbr=on}}. 19% has a depth of 0 to {{convert|1,000|m|ft|abbr=on}}. Thus, Japan possesses one of the largest ocean territories with a combination of all depths, from shallow to very deep.<ref name="japan-seabed">{{cite web |date=September 20, 2005 |title=What is the Volume of Japan's 200-nm Exclusive Economic Zone? |url=https://www.spf.org/en/opri/newsletter/123_3.html?full=123_3|archive-url=https://web.archive.org/web/20190729135457/https://www.spf.org/en/opri/newsletter/123_3.html?full=123_3|archive-date=July 29, 2019|access-date=30 July 2019 |publisher=The Ocean Policy Research Institute |format=website}}</ref> Multiple long undersea mountain ranges stretch from Japan's main islands to the south. They occasionally reach above the sea surface as islands. East of the undersea mountain ranges are three oceanic trenches: the Kuril–Kamchatka Trench (max depth {{convert|10,542|m|ft|abbr=on}}), Japan Trench (max depth {{convert|10,375|m|ft|abbr=on}}), and Izu–Ogasawara Trench (max depth {{convert|9,810|m|ft|abbr=on}}).

There are large quantities of marine life and mineral resources in the ocean and seabed of Japan. At a depth of over {{convert|1,000|m|ft|abbr=on}}, there are minerals such as manganese nodules, cobalt in the crust, and hydrothermal deposits. Within the island straits remarkable subaqueous dunes are present on the shelf.<ref>{{cite journal |last1=Ikehara |first1=Ken |last2=Kinoshita |first2=Yasumasa |title=Distribution and origin of subaqueous dunes on the shelf of Japan |journal=Marine Geology |date=August 1994 |volume=120 |issue=1–2 |pages=75–87 |doi=10.1016/0025-3227(94)90078-7 |bibcode=1994MGeol.120...75I }}</ref>

==Geology== [[File:Japan separation.png|thumb|upright=1.3|The islands comprising the Japanese Archipelago were separated from the Asian continent by back-arc spreading.]] thumb|upright=1.3|Tectonic map of Japan (French) {{main|Geology of Japan}}

===Tectonic plates=== The Japanese archipelago is the result of subducting tectonic plates over several 100 million years, from the mid-Silurian (443.8 Mya) to the Pleistocene (11,700 years ago). Approximately {{convert|15000|km|mi|abbr=on}} of oceanic floor has passed under the Japanese archipelago in the last 450 million years, with most being fully subducted. It is considered a mature island arc.

The islands of Japan were created by tectonic plate movements: * Tohoku (upper half of Honshu), Hokkaido, the Kuril Islands, and Sakhalin are located on the Okhotsk Plate. This is a minor tectonic plate bounded to the north by the North American Plate.<ref>Seno et al., 1996 Journal of Geophysical Research; https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/96JB00532{{Dead link|date=December 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>Apel et al., 2006 Geophysical Research Letters; http://onlinelibrary.wiley.com/wol1/doi/10.1029/2006GL026077/full</ref> The Okhotsk Plate is bounded on the east by the Pacific Plate at the Kuril–Kamchatka Trench and the Japan Trench. It is bounded on the south by the Philippine Sea Plate at the Nankai Trough. On the west, it is bound by the Eurasian Plate, and possibly on the southwest, by the Amurian Plate. The northeastern boundary is the Ulakhan Fault.<ref>{{Cite journal |last1=Hindle |first1=D. |last2=Fujita |first2=K. |last3=Mackey |first3=K. |date=2009-09-17 |title=Deformation of the Northwestern Okhotsk Plate: How is it happening? |url=https://smsps.copernicus.org/articles/4/147/2009/ |journal=Stephan Mueller Special Publication Series |language=English |volume=4 |pages=147–156 |doi=10.5194/smsps-4-147-2009 |doi-access=free |bibcode=2009SMSPS...4..147H |issn=1868-4556}}</ref> * The southern half of Honshu, Shikoku, and most of Kyushu are located on the Amurian Plate. * The southern tip of Kyushu and the Ryukyu islands are located on the Okinawa Plate. * The Nanpō Islands are on the Philippine Sea Plate.

The Pacific Plate and Philippine Sea Plate are subduction plates. They are deeper than the Eurasian plate. The Philippine Sea Plate moves beneath the continental Amurian Plate and the Okinawa Plate to the south. The Pacific Plate moves under the Okhotsk Plate to the north. These subduction plates pulled Japan eastward and opened the Sea of Japan by back-arc spreading around 15 million years ago.<ref name="Barnes">{{cite web |url=http://shinku.nichibun.ac.jp/jpub/pdf/jr/IJ1501.pdf |last=Barnes |first=Gina L. |title=Origins of the Japanese Islands: The New "Big Picture" |publisher=University of Durham |year=2003|access-date=August 11, 2009|archive-url=https://web.archive.org/web/20110428043510/http://shinku.nichibun.ac.jp/jpub/pdf/jr/IJ1501.pdf|archive-date=April 28, 2011|url-status=dead}}</ref> The Strait of Tartary and the Korea Strait opened much later. La Pérouse Strait formed about 60,000 to 11,000 years ago, closing the path used by mammoths, which had earlier moved to northern Hokkaido.<ref name="brit" /> The eastern margin of the Sea of Japan is an incipient subduction zone consisting of thrust faults that formed from the compression and reactivation of old faults involved in earlier rifting.<ref name="Tamaki85">{{cite journal |last1=Tamaki |first1=Kensaku |last2=Honza |first2=Eiichi |title=Incipient subduction and deduction along the eastern margin of the Japan Sea |journal=Tectonophysics |date=20 October 1985 |volume=119 |issue=1–4 |pages=381–406 |doi=10.1016/0040-1951(85)90047-2 |bibcode=1985Tectp.119..381T }}</ref>

The subduction zone is where the oceanic crust slides beneath the continental crust or other oceanic plates. This is because the oceanic plate's lithosphere has a higher density. Subduction zones are sites that usually have a high rate of volcanism and earthquakes.<ref>{{Cite journal |author1=Martínez-López, M.R. |author2=Mendoza, C. |year=2016 |title=Acoplamiento sismogénico en la zona de subducción de Michoacán-Colima-Jalisco, México |journal=Boletín de la Sociedad Geológica Mexicana |language=es |volume=68 |issue=2 |pages=199–214 |doi=10.18268/BSGM2016v68n2a3|doi-access=free|bibcode=2016BoSGM..68..199M }}</ref> Additionally, subduction zones develop belts of deformation.<ref>{{cite web |url=http://snl.no/orogenese |title=Orogenese |access-date=July 2, 2014 |date=February 14, 2009 |website=Store norske leksikon |language=no |archive-date=July 14, 2014 |archive-url=https://web.archive.org/web/20140714212710/http://snl.no/orogenese |url-status=live }}</ref> The subduction zones on the east side of the Japanese archipelago cause frequent low-intensity earth tremors. Major earthquakes, volcanic eruptions, and tsunamis occur several times per century. It is part of the Pacific Ring of Fire.<ref name="Barnes" /> Northeastern Japan, north of the Tanakura fault, had high volcanic activity 14–17 million years before the present.<ref name="atlas">{{cite web |url=https://confit.atlas.jp/guide/event-img/jpgu2016/SGL36-P01/public/pdf?type=in |publisher=confit.atlas.jp |title=Yurie SAWAHATA, Makoto Okada, Jun Hosoi, Kazuo Amano, "Paleomagnetic study of Neogene sediments in strike-slip basins along the Tanakura Fault |access-date=July 16, 2017 |archive-date=October 20, 2022 |archive-url=https://web.archive.org/web/20221020122154/https://confit.atlas.jp/guide/event-img/jpgu2016/SGL36-P01/public/pdf?type=in |url-status=live }}</ref>

=== Median Tectonic Line === [[Image:Tectonic map of southwest Japan.png|thumb|upright=1.3|left|The red line represents the Median Tectonic Line. The orange-shaded region is Fossa Magna, bounded by the Itoigawa-Shizuoka Tectonic Line (western blue line).]] The Japan Median Tectonic Line (MTL) is Japan's longest fault system.<ref name="d">{{cite encyclopedia |encyclopedia=Dijitaru Daijisen |title=中央構造線 |url=http://rekishi.jkn21.com/ |access-date=2012-09-21 |year=2012 |publisher=Shogakukan |location=Tokyo |language=ja |trans-title=Japan Median Tectonic Line (MTL) |oclc=56431036 |url-status=dead |archive-url=https://web.archive.org/web/20070825113418/http://rekishi.jkn21.com/ |archive-date=2007-08-25}}</ref><ref name="n">{{cite encyclopedia |encyclopedia=Nihon Daihyakka Zensho (Nipponika) |title=中央構造線 |url=http://rekishi.jkn21.com/ |access-date=2012-09-21 |year=2012 |publisher=Shogakukan |location=Tokyo |language=ja |trans-title=Japan Median Tectonic Line |oclc=153301537 |url-status=dead |archive-url=https://web.archive.org/web/20070825113418/http://rekishi.jkn21.com/ |archive-date=2007-08-25}}</ref> The MTL begins near Ibaraki Prefecture, where it connects with the Itoigawa-Shizuoka Tectonic Line (ISTL) and the Fossa Magna. It runs parallel to Japan's volcanic arc, passing through central Honshū to near Nagoya, through Mikawa Bay, then through the Seto Inland Sea from the Kii Channel and Naruto Strait to Shikoku along the Sadamisaki Peninsula and the Bungo Channel and Hōyo Strait to Kyūshū.<ref name="n" />

The MTL moves right-lateral strike-slip at about 5–10 millimeters per year.<ref>Okada, A., On the Quaternary faulting along the Median Tectonic Line, in ''Median Tectonic Line'' (in Japanese with English abstract), edited by R. Sugiyama, pp. 49–86, Tokai University Press, Tokyo, 1973.</ref> The sense of motion is consistent with the direction of the Nankai Trough's oblique convergence. The rate of motion on the MTL is much less than the rate of convergence at the plate boundary. This makes it difficult to distinguish the motion on the MTL from interseismic elastic straining in GPS data.<ref>Miyazaki, S. and Heki, K. (2001) Crustal velocity field of southwest Japan: Subduction and arc-arc collision, ''Journal of Geophysical Research'', vo. 106, no. B3.</ref>

===Oceanic trenches=== [[File:Japan_Trench_Map.jpg|thumb|upright=1.3|The map depicts the Kuril–Kamchatka Trench, Japan Trench, Izu–Ogasawara Trench, and Mariana Trench.]] East of the Japanese archipelago are three oceanic trenches. * The Kuril–Kamchatka Trench is in the northwest Pacific Ocean. It lies off the southeast coast of Kamchatka and parallels the Kuril Island chain to meet the Japan Trench east of Hokkaido.<ref name=USGS>Rhea, S., et al., 2010, ''Seismicity of the Earth 1900–2007, Kuril–Kamchatka arc and vicinity'', U.S. Geological Survey Open-File Report 2010-1083-C, 1 map sheet, scale 1:5,000,000 https://pubs.usgs.gov/of/2010/1083/c/ {{Webarchive|url=https://web.archive.org/web/20171209203950/https://pubs.usgs.gov/of/2010/1083/c/ |date=2017-12-09 }}</ref> * The Japan Trench extends {{convert|8000.|km|mi|abbr=on}} from the Kuril Islands to the northern end of the Izu Islands. Its deepest part is {{convert|8046|m|ft|abbr=on}}.<ref>{{cite web |url=https://www.gmrt.org/about/index.php |title=GMRT Overview |author1=J. Morton |author2=V. Ferrini |author3=S. O'Hara |website=www.gmrt.org |access-date=2018-05-27 |archive-date=2023-03-08 |archive-url=https://web.archive.org/web/20230308011339/https://www.gmrt.org/about/index.php |url-status=live }}</ref> The Japan Trench is created as the oceanic Pacific Plate subducts beneath the continental Okhotsk Plate. The subduction process causes bending of the down-going plate, creating a deep trench. Continuous movement on the subduction zone associated with the Japan Trench is one of the main causes of tsunamis and earthquakes in northern Japan, including the megathrust 2011 Tōhoku earthquake and tsunami. The rate of subduction associated with the Japan Trench has been recorded at about {{cvt|7.9|–|9.2|cm}}/year.<ref name="revel"/> * The Izu–Ogasawara Trench is south of the Japan Trench in the western Pacific Ocean. It consists of the Izu Trench (at the north) and the Bonin Trench (at the south, west of the Ogasawara Plateau).<ref>{{cite web |title=Locator map |url=http://www.soest.hawaii.edu/expeditions/mariana/images/regional_locator.jpg |website=Expedition to the Mariana forearc |publisher=School of Ocean and Earth Science and Technology at the University of Hawaii |access-date=2018-10-01 |archive-date=2016-03-03 |archive-url=https://web.archive.org/web/20160303201252/http://www.soest.hawaii.edu/expeditions/mariana/images/regional_locator.jpg |url-status=live }}</ref> It stretches to the northernmost section of the Mariana Trench.<ref>{{Cite web |url=http://www.agu.org/pubs/crossref/2000/1999JC900324.shtml |title=Deep current structure above the Izu-Ogasawara Trench |access-date=2018-10-01 |archive-date=2012-03-01 |archive-url=https://web.archive.org/web/20120301205341/http://www.agu.org/pubs/crossref/2000/1999JC900324.shtml |url-status=dead}}</ref> The Izu–Ogasawara Trench is an extension of the Japan Trench. There, the Pacific Plate is being subducted beneath the Philippine Sea Plate, creating the Izu Islands and Bonin Islands on the Izu–Bonin–Mariana Arc system.<ref name="izu-ogasawara-arc">{{cite web |url=http://www.terrapub.co.jp/journals/EPS/pdf/2006e/5808e033.pdf |archive-url=https://web.archive.org/web/20171029065154/http://www.terrapub.co.jp/journals/EPS/pdf/2006e/5808e033.pdf |archive-date=October 29, 2017 |title=Crustal structure of the ocean-island arc transition at the mid Izu–Ogasawara (Bonin) arc margin |publisher=Earth, Planets and Space |access-date=October 2, 2018}}</ref>

===Composition=== The Japanese islands are formed of the mentioned geological units parallel to the subduction front. The parts of islands facing the Pacific Plate are typically younger and display a larger proportion of volcanic products, while island parts facing the Sea of Japan are mostly heavily faulted and folded sedimentary deposits. In northwest Japan, there are thick quaternary deposits. This makes the determination of the geological history and composition difficult, and it is not yet fully understood.<ref name="gsj">{{cite web |url=https://www.gsj.jp/en/education/geomap-e/geology-e.html |publisher=gsj.jp |title=Geology of Japan{{pipe}}Geological Survey of Japan, AIST{{pipe}}産総研地質調査総合センター / Geological Survey of Japan, AIST |access-date=July 16, 2017 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201125222/https://www.gsj.jp/en/education/geomap-e/geology-e.html |url-status=live }}</ref>

The Japanese island arc system has distributed volcanic series where the volcanic rocks change from tholeiite—calc-alkaline—alkaline with increasing distance from the trench.<ref name=":2">{{Cite journal |last=Gill |first=J.B. |date=1982 |title=Andesites: Orogenic andesites and related rocks |journal=Geochimica et Cosmochimica Acta |volume=46 |issue=12 |pages=2688 |doi=10.1016/0016-7037(82)90392-1 |issn=0016-7037}}</ref><ref>{{cite journal |last1=Pearce |first1=J |last2=Peate |first2=D |date=1995 |title=Tectonic Implications of the Composition of Volcanic ARC Magmas |journal=Annual Review of Earth and Planetary Sciences |pages=251–285 |volume=23 |issue=1 |doi=10.1146/annurev.ea.23.050195.001343 |bibcode=1995AREPS..23..251P}}</ref> The geologic province of Japan is mostly basin and has a bit of extended crust.<ref>{{cite web |title=Geologic Province and Thermo-Tectonic Age Maps |url=https://earthquake.usgs.gov/research/structure/crust/maps.php |website=Earthquake Hazards Program |publisher=United States Geological Survey |access-date=6 June 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140607001305/http://earthquake.usgs.gov/research/structure/crust/maps.php |archive-date=7 June 2014}}</ref>

==Growing archipelago== The Japanese archipelago grows gradually because of perpetual tectonic plate movements, earthquakes, stratovolcanoes, and land reclamation in the Ring of Fire.

For example, during the 20th century, several new volcanoes emerged, including Shōwa-shinzan on Hokkaido and Myōjin-shō off the Bayonnaise Rocks in the Pacific.<ref name="volcanoes-japan" /> The 1914 Sakurajima eruption produced lava flows that connected the former island with the Ōsumi Peninsula in Kyushu.<ref>{{cite journal |author=Davison C |title=The Sakura-Jima Eruption of January, 1914 |journal=Nature |volume=98 |issue=2447 |pages=57–58 |date=1916-09-21 |doi=10.1038/098057b0 |bibcode=1916Natur..98...57D |s2cid=3964260 |url=https://zenodo.org/record/1429613 |access-date=2019-07-01 |archive-date=2019-12-27 |archive-url=https://web.archive.org/web/20191227072926/https://zenodo.org/record/1429613 |url-status=live }}</ref> It is the most active volcano in Japan.<ref>{{cite web |url=https://www.nippon.com/en/features/h00194/ |title=Sakurajima, Japan's Most Active Volcano |date=2018-05-16 |website=nippon.com |publisher=Nippon Communications Foundation |access-date=2018-08-02 |df=mdy-all |archive-date=2018-08-03 |archive-url=https://web.archive.org/web/20180803013956/https://www.nippon.com/en/features/h00194/ |url-status=live }}</ref>

During the 2013 eruption southeast of Nishinoshima, a new, unnamed volcanic island emerged from the sea.<ref name="Hokkaido">{{cite news |title=しんとう |url=http://www.hokkaido-np.co.jp/news/fourseasons/514834.html |access-date=16 January 2014 |newspaper=Hokkaidō Shinbun |date=12 January 2014 |archive-date=16 January 2014 |archive-url=https://web.archive.org/web/20140116131130/http://www.hokkaido-np.co.jp/news/fourseasons/514834.html |url-status=live }}</ref> Erosion and shifting sands caused the new island to merge with Nishinoshima.<ref name=kotobank>{{cite web |title=Nishinoshima |url=http://kotobank.jp/word/%E8%A5%BF%E4%B9%8B%E5%B3%B6 |work=Kotobank |publisher=Asahi Shinbun |access-date=18 February 2014 |archive-date=4 August 2014 |archive-url=https://web.archive.org/web/20140804105528/http://kotobank.jp/word/%E8%A5%BF%E4%B9%8B%E5%B3%B6 |url-status=live }}</ref><ref name="AsahiEng">{{cite news |title=Lava flow connects new islet with Nishinoshima island |url=http://ajw.asahi.com/article/behind_news/social_affairs/AJ201312260070 |access-date=27 December 2013 |newspaper=Asahi Shimbun |date=26 December 2013 |archive-date=28 December 2013 |archive-url=https://web.archive.org/web/20131228011619/http://ajw.asahi.com/article/behind_news/social_affairs/AJ201312260070 |url-status=dead }}</ref> A 1911 survey determined the caldera was {{convert|107|m|ft|abbr=on}} at its deepest.<ref name=Nakano3>{{cite web |last=Nakano |first=Shun |title=Kaitei chikei |url=https://gbank.gsj.jp/volcano/Act_Vol/nishinoshima/page3.html |work=Nishinoshima Kazan |publisher=Geological Survey of Japan |access-date=17 February 2014 |language=ja |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304121441/https://gbank.gsj.jp/volcano/Act_Vol/nishinoshima/page3.html |url-status=live }}</ref>

The 2011 Tōhoku earthquake and tsunami caused portions of northeastern Japan to shift by {{convert|2.4|m}} closer to North America.<ref name=DW>{{Cite news |title=Quake shifted Japan by over two metres |url=http://www.dw-world.de/dw/article/0,,14909967,00.html |work=Deutsche Welle |date=14 March 2011 |access-date=14 March 2011 |archive-url=https://web.archive.org/web/20110315181343/http://www.dw-world.de/dw/article/0,,14909967,00.html |archive-date=15 March 2011 |url-status=live |df=dmy}}</ref> This made some sections of Japan's landmass wider than before.<ref name="NYTimes-Chang2011-03-13">{{Cite news |first=Kenneth |last=Chang |title=Quake Moves Japan Closer to U.S. and Alters Earth's Spin |url=https://www.nytimes.com/2011/03/14/world/asia/14seismic.html |work=The New York Times |date=13 March 2011 |access-date=14 March 2011| archive-url= https://web.archive.org/web/20110316002603/http://www.nytimes.com/2011/03/14/world/asia/14seismic.html| archive-date= 16 March 2011 | url-status= live}}</ref> The areas of Japan closest to the epicenter experienced the largest shifts.<ref name="NYTimes-Chang2011-03-13" /> A {{convert|400|km|mi|adj=mid}} stretch of coastline dropped vertically by {{convert|0.6|m}}, allowing the tsunami to travel farther and faster onto land.<ref name="NYTimes-Chang2011-03-13" /> On 6 April, the Japanese coast guard said that the earthquake shifted the seabed near the epicenter {{convert|24|metres}} and elevated the seabed off the coast of Miyagi Prefecture by {{convert|3|metres}}.<ref>[http://us.mobile.reuters.com/article/environmentNews/idUSTRE73607620110407?irpc=932 Japan seabed shifted 24 metres after March quake {{pipe}} Reuters.com] {{webarchive|url=https://web.archive.org/web/20110414005051/http://us.mobile.reuters.com/article/environmentNews/idUSTRE73607620110407?irpc=932 |date=14 April 2011 }}</ref> A report by the Japan Agency for Marine-Earth Science and Technology, published in ''Science'' on 2 December 2011, concluded that the seabed in the area between the epicenter and the Japan Trench moved {{convert|50|metres}} east-southeast and rose about {{convert|7|metres}} as a result of the quake. The report also stated that the quake caused several major landslides on the seabed in the affected area.<ref>Jiji Press, "March temblor shifted seabed by {{convert|50|metres}}", ''Japan Times'', 3 December 2011, p. 1.</ref>

==Sea of Japan== thumb|upright=1.3|Sea of Japan {{main|Sea of Japan}}

===History=== During the Pleistocene (spanning 2.58 million-11,700 years ago) glacial cycles, the Japanese islands may have occasionally been connected to the Eurasian Continent via the Korea Strait and the Korean Peninsula or Sakhalin. The Sea of Japan was considered to be a frozen inner lake because of the lack of the warm Tsushima Current. Various plants and large animals, such as the elephant ''Palaeoloxodon naumanni,'' migrated into the Japanese archipelago.<ref name = sealevel>{{cite journal |last1=Park |first1=S.-C. |last2=Yoo |first2=D.-G. |last3=Lee |first3=C.-W. |last4=Lee |first4=E.-I. |title=Last glacial sea-level changes and paleogeography of the Korea (Tsushima) Strait |journal=Geo-Marine Letters |date=26 September 2000 |volume=20 |issue=2 |pages=64–71 |doi=10.1007/s003670000039 |bibcode=2000GML....20...64P |s2cid=128476723}}</ref>

The Sea of Japan was a landlocked sea when the land bridge of East Asia existed circa 18,000 BCE. During the glacial maximum, the marine elevation was 200 meters lower than present. Thus, Tsushima island in the Korea Strait was a land bridge that connected Kyushu and the southern tip of Honshu with the Korean peninsula. There were still several kilometers of sea to the west of the Ryukyu islands, and most of the Sea of Japan was open sea with a mean depth of {{cvt|1,752|m|ft}}. Comparatively, most of the Yellow Sea (Yellow Plane) had a semi-arid climate (dry steppe) because it was relatively shallow, with a mean depth of {{convert|44|m|abbr=on}}. The Korean Peninsula was landlocked on the entire west and south sides of the Yellow Plane.<ref>{{cite book |url=https://books.google.com/books?id=W_Hdu9QrD9YC&pg=PA16 |title=Pre-Industrial Korea and Japan in Environmental Perspective |first=Conrad D. |last=Totman |year=2004|publisher=BRILL |access-date=2007-02-02 |isbn=978-9004136267}}</ref> The onset of the formation of the Japan Arc was in the Early Miocene (23 million years ago).<ref name="Kameda 2011">Kameda Y. & Kato M. (2011). "Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago". ''BMC Evolutionary Biology'' '''11''': 118. {{doi|10.1186/1471-2148-11-118|doi-access=free}}.</ref> The Early Miocene period was when the Sea of Japan started to open and the northern and southern parts of the Japanese archipelago separated from each other.<ref name="Kameda 2011"/> The Sea of Japan expanded during the Miocene.<ref name="Kameda 2011"/>

The northern part of the Japanese archipelago was further fragmented until the orogenesis of the northeastern Japanese archipelago began in the Late Miocene. The orogenesis of the high mountain ranges in northeastern Japan started in the Late Miocene and lasted into the Pliocene.<ref name="Kameda 2011"/> The southern part of the Japanese archipelago remained a relatively large landmass. The land area expanded northward during the Miocene.<ref name="Kameda 2011"/>

[[File:Last_Glacial_Maximum_Vegetation_Map.svg|thumb|upright=1.5|Vegetation during the Last Glacial Maximum (16,000 BCE)]]

During the advance of the last Ice Age, the world sea level dropped. This dried up and closed the exit straits of the Sea of Japan one by one. The deepest, and thus the last to close, was the western channel of the Korea Strait. There is controversy as to whether the Sea of Japan became a huge, cold inland lake.<ref name = sealevel/> The Japanese archipelago had a taiga biome (open boreal woodlands). It was characterized by coniferous forests consisting mostly of pines, spruces, and larches. Hokkaido, Sakhalin, and the Kuril islands had mammoth steppe biome (steppe-tundra). The vegetation was dominated by palatable high-productivity grasses, herbs, and willow shrubs.

===Present=== The Sea of Japan has a surface area of {{cvt|978000|km2|sqmi}}, a mean depth of {{cvt|1,752|m|ft}}, and a maximum depth of {{cvt|3742|m|ft}}. It has a carrot-like shape, with the major axis extending from southwest to northeast and a wide southern part narrowing toward the north. The coastal length is about {{cvt|7600|km|mi}}, with the largest part ({{cvt|3240|km|mi|disp=or}}) belonging to Russia. The sea extends from north to south for more than {{cvt|2255|km|mi}} and has a maximum width of about {{cvt|1070|km|mi}}.<ref name=bse>[http://bse.sci-lib.com/article128477.html Sea of Japan] {{Webarchive|url=https://web.archive.org/web/20120123133920/http://bse.sci-lib.com/article128477.html |date=2012-01-23 }}, ''Great Soviet Encyclopedia'' {{in lang|ru}}</ref>

There are three major basins: the Yamato Basin in the southeast, the Japan Basin in the north, and the Tsushima Basin in the southwest.<ref name=brit>[https://www.britannica.com/EBchecked/topic/300960/Sea-of-Japan Sea of Japan] {{Webarchive|url=https://web.archive.org/web/20150608142442/http://www.britannica.com/EBchecked/topic/300960/Sea-of-Japan |date=2015-06-08 }}, Encyclopædia Britannica on-line</ref> The Japan Basin has an oceanic crust and is the deepest part of the sea, whereas the Tsushima Basin is the shallowest, with depths below {{cvt|2300|m|ft}}. The Yamato Basin and Tsushima Basin have thick oceanic crusts.<ref name = bse/> The continental shelves of the sea are wide on the eastern shores of Japan. On the western shores, they are narrow, particularly along the Korean and Russian coasts, averaging about {{cvt|30|km|mi}}.

The geographical location of the Japanese archipelago has defined the Sea of Japan for millions of years. Without the Japanese archipelago, it would just be the Pacific Ocean. The term has been the international standard since at least the early 19th century.<ref name="Basic Position">{{cite web |url=http://www1.kaiho.mlit.go.jp/GIJUTSUKOKUSAI/nihonkai/position_eng.htm |title=Japanese Basic Position on the Naming of the "Japan Sea" |publisher=Japan Coast Guard |date=March 1, 2005 | url-status = dead | archive-url = https://web.archive.org/web/20110524092704/http://www1.kaiho.mlit.go.jp/GIJUTSUKOKUSAI/nihonkai/position_eng.htm | archive-date = May 24, 2011}}</ref> In 2012, the International Hydrographic Organization, the international governing body for naming bodies of water around the world, recognized the term "Sea of Japan" as the only title for the sea.<ref>Kyodo News, "IHO nixes 'East Sea' name bid", ''Japan Times'', 28 April 2012, p. 2; Rabiroff, Jon, and Yoo Kyong Chang, "[http://www.stripes.com/news/pacific/korea/agency-rejects-south-korea-s-request-to-rename-sea-of-japan-1.175687 Agency rejects South Korea's request to rename Sea of Japan] {{Webarchive|url=https://web.archive.org/web/20160920033907/http://www.stripes.com/news/pacific/korea/agency-rejects-south-korea-s-request-to-rename-sea-of-japan-1.175687 |date=2016-09-20 }}", ''Stars and Stripes'', 28 April 2012, p. 5.</ref>

==Ocean currents== [[File:Japan%27s_ocean_currents.PNG|thumb|upright=1.3|The ocean currents surrounding the Japanese archipelago: 1. Kuroshio 2. Kuroshio extension 3. Kuroshio countercurrent 4. Tsushima Current 5. Tsugaru Current 6. Sōya Current 7. Oyashio 8. Liman Current]]

The Japanese archipelago is surrounded by eight ocean currents. * The {{nihongo|'''Kuroshio'''|黒潮 ("くろしお")|"Black Tide"}} is a warm, north-flowing ocean current on the west side of the Ryukyu Islands and along the east coast of Kyushu, Shikoku, and Honshu. It is a strong western boundary current and part of the North Pacific ocean gyre. * The '''Kuroshio Current''' starts on the east coast of Luzon, Philippines, past Taiwan, and flows northeastward past Japan, where it merges with the easterly drift of the North Pacific Current.<ref name="EB1911">{{cite EB1911 |wstitle=Kuro Siwo |volume=15 |page=953}}</ref> It transports warm, tropical water northward toward the polar region. The Kuroshio extension is a northward continuation of the Kuroshio Current in the northwestern Pacific Ocean. The Kuroshio countercurrent flows southward to the east of the Kuroshio current in the Pacific Ocean and Philippine Sea. ** The winter-spawning Japanese Flying Squid are associated with the Kuroshio Current. The eggs and larvae develop during winter in the East China Sea, and the adults travel with minimum energy via the Kuroshio Current to the rich northern feeding grounds near northwestern Honshu and Hokkaido.<ref name="mann">Mann, K.H. and J.R.N. Lazier. (2006). ''Dynamics of Marine Ecosystems''. Blackwell Scientific Publications, 2nd Edition</ref> * The {{nihongo|'''Tsushima Current'''|対馬海流|Tsushima Kairyū}} is a branch of the Kuroshio Current. It flows along the west coast of Kyushu and Honshu into the Sea of Japan. * The {{nihongo|'''Oyashio'''|親潮||"Parental Tide"}} current is a cold subarctic ocean current that flows southward and circulates counterclockwise along the east coast of Hokkaido and northeastern Honshu in the western North Pacific Ocean. The waters of the Oyashio Current originate in the Arctic Ocean and flow southward via the Bering Sea, passing through the Bering Strait and transporting cold water from the Arctic Sea into the Pacific Ocean and the Sea of Okhotsk. It collides with the Kuroshio Current off the eastern shore of Japan to form the North Pacific Current. The nutrient-rich Oyashio is named for its metaphorical role as the {{nihongo|parent|親|''oya''}} that provides for and nurtures marine organisms.<ref>{{cite book |chapter=Kuroshio and Oyashio Currents |date=2001 |last=Qiu |first=Bo |title=Encyclopedia of Ocean Sciences |pages=1413–25 |publisher=Academic Press |chapter-url=http://www.soest.hawaii.edu/oceanography/bo/Q01.pdf |quote=The upwelled, nutrient-rich water feeds the Oyashio from the north and leads to its nomenclature, parent (''oya'') stream (''shio''). |access-date=2018-10-25 |archive-date=2021-08-02 |archive-url=https://web.archive.org/web/20210802164839/http://www.soest.hawaii.edu/oceanography/bo/Q01.pdf |url-status=live }}</ref><ref>{{cite book |last=Glattstein |first=Judy |title=Enhance Your Garden with Japanese Plants |url=https://books.google.com/books?id=BAhIAAAAYAAJ |year=1996 |publisher=Kodansha International |isbn=978-1-56836-137-6 |page=16 |quote=[...] currents whirl around and ascend, and nourish microscopic plankton. Oyashio is thus the parent of fishes |access-date=2018-10-25 |archive-date=2023-08-08 |archive-url=https://web.archive.org/web/20230808005358/https://books.google.com/books?id=BAhIAAAAYAAJ |url-status=live }}</ref> * The '''Liman Current''' is a southward-flowing cold ocean current that flows from the Strait of Tartary along the Asian continent in the Sea of Japan.<ref>{{cite web |url=http://www3.pa.hrr.mlit.go.jp/hokurikukankyo/shizen/ryukyo/tsusima.html| archive-url = https://web.archive.org/web/20140308151146/http://www3.pa.hrr.mlit.go.jp/hokurikukankyo/shizen/ryukyo/tsusima.html |title=海流 |publisher=北陸地方整備局 (Hokuriku Regional Development Bureau)| access-date = 2014-03-08| archive-date = 2014-03-08| url-status= dead |date=2018-04-14}}</ref> * The {{nihongo|'''Tsugaru Warm Current'''|津軽暖流|Tsugaru Danryū}} originates when the Tsushima Current is divided in two as it flows through the west entrance of the Tsugaru Strait, and along the La Perouse Strait at the north coast of Hokkaido it becomes the {{nihongo|'''Sōya Warm Current'''|宗谷暖流|Sōya Danryū}}. The flow rate is 1 to 3 knots. There is a relatively stronger flow in the summer than in the winter.<ref name="milt1">{{Cite web |url=http://www1.kaiho.mlit.go.jp/KAN1/soudan/kairyu.html |title=北海道周辺の海流第一管区海上保安本部 |access-date=2018-10-25 |archive-date=2020-01-10 |archive-url=https://web.archive.org/web/20200110005019/https://www1.kaiho.mlit.go.jp/KAN1/soudan/kairyu.html |url-status=live }}</ref>

==Natural resources== {{Main|Energy in Japan|Mining in Japan}}

===Land resources=== There are small deposits of coal, oil, iron, and minerals in the Japanese archipelago.<ref name="CIA World Factbook"/> Japan is scarce in critical natural resources and has long been heavily dependent on imported energy and raw materials.<ref name="CIA World Factbook"/><ref>{{cite web |title=Can nuclear power save Japan from peak oil? |url=http://ourworld.unu.edu/en/can-nuclear-power-save-japan-from-peak-oil/ |publisher=Our World 2.0 |access-date=March 15, 2011 |date=February 2, 2011 |archive-date=January 16, 2013 |archive-url=https://web.archive.org/web/20130116212759/http://ourworld.unu.edu/en/can-nuclear-power-save-japan-from-peak-oil/ |url-status=live }}</ref> The oil crisis in 1973 encouraged the efficient use of energy.<ref>{{cite web |last=Sekiyama |first=Takeshi |title=Japan's international cooperation for energy efficiency and conservation in Asian region |url=http://nice.erina.or.jp/en/pdf/C-SEKIYAMA.pdf|archive-url=https://web.archive.org/web/20080216005103/http://nice.erina.or.jp/en/pdf/C-SEKIYAMA.pdf |archive-date=February 16, 2008 |publisher=Energy Conservation Center|access-date=January 16, 2011}}</ref> Japan has therefore aimed to diversify its sources and maintain high levels of energy efficiency.<ref>{{cite web |title=U.S. Relations with Japan |date=11 March 2016 |url=https://2009-2017.state.gov/r/pa/ei/bgn/4142.htm |publisher=U.S. Department of State |access-date=23 May 2019 |archive-date=4 June 2019 |archive-url=https://web.archive.org/web/20190604185025/https://2009-2017.state.gov/r/pa/ei/bgn/4142.htm |url-status=live }}</ref> In regards to agricultural products, the self-sufficiency rate of most items is less than 100%, except for rice. Rice has 100% food self-sufficiency. This makes it difficult to meet Japan's food demand without imports.

===Marine resources=== [[File:Japan Exclusive Economic Zones.png|thumb|right|upright=1.3|Japan's exclusive economic zones:{{legend|#dd12c2|Japan's EEZ}}{{legend|#f080e1|Joint regime with Republic of Korea}}{{legend|#f2d1ee|EEZ claimed by Japan, disputed by others}}]] The exclusive economic zone of Japan has an estimated large quantity of mineral resources such as methane clathrate, natural gas, metallic minerals, and rare-earth mineral reserves. Seabed mineral resources such as manganese nodules, cobalt-rich crust, and submarine hydrothermal deposits are located at depths over {{convert|1000|m|ft|abbr=on}}.<ref name="japan-seabed"/> Most of these deep-sea resources are unexplored at the seabed. Japan's mining law restricts offshore oil and gas production. There are technological hurdles to mine at such extreme depths and to limit the ecological impact. There are no successful commercial ventures that mine the deep sea yet. So currently, there are few deep sea mining projects to retrieve minerals or deepwater drilling on the ocean floor.

It is estimated that there are approximately 40 trillion cubic feet of methane clathrate in the eastern Nankai Trough of Japan.<ref name="天然ガスの本">藤田和男ほか監修佐々木詔雄ほか編著『天然ガスの本』日刊工業新聞 2008年3月25日初版1刷発行 {{ISBN|978-4-526-06024-3}}</ref> As of 2019, the methane clathrate in the deep sea remains unexploited because the necessary technology has not been established yet. This is why, currently, Japan has very limited proven reserves like crude oil.

The Kantō region alone is estimated to have over 400 billion cubic meters of natural gas reserves. It forms a Minami Kantō gas field in the area spanning Saitama, Tokyo, Kanagawa, Ibaraki, and Chiba prefectures. However, mining is strictly regulated in many areas because it is directly below Tokyo and is only slightly mined on the Bōsō Peninsula. In Tokyo and Chiba Prefecture, there have been frequent accidents with natural gas that was released naturally from the Minami Kantō gas field.<ref>{{Cite journal |doi=10.14863/geosocabst.2008.0.426.0 |year=2008 |volume=2008 |last1=金子 |first1=信行 |title=関東平野下に賦存する可燃性天然ガスについて |journal=日本地質学会学術大会講演要旨 |last2=佐脇 |first2=貴幸 |last3=棚橋 |first3=学.}}</ref>

In 2018, {{convert|250|km|mi|abbr=on}} south of Minami-Tori-shima at {{convert|5700|m|ft|abbr=on}} deep, approximately 16 million tons of rare-earth minerals were discovered by JAMSTEC in collaboration with Waseda University and the University of Tokyo.<ref>{{cite news |title=Centuries worth of rare earth elements found in Japan's EEZ |url=http://www.asahi.com/ajw/articles/AJ201804170045.html |newspaper=The Asahi Shimbun |date=April 17, 2018| archive-url=https://web.archive.org/web/20180621021131/http://www.asahi.com/ajw/articles/AJ201804170045.html|archive-date=June 21, 2018|access-date=February 24, 2019}}</ref>

====Marine life==== Japan maintains one of the world's largest fishing fleets and accounts for nearly 15% of the global catch (2014).<ref name="CIA World Factbook"/> In 2005, Japan ranked sixth in the world in the tonnage of fish caught.<ref name="World review of fisheries and aquaculture">{{cite web |url=http://www.fao.org/docrep/w9900e/w9900e02.htm |title=World review of fisheries and aquaculture |website=Food and Agriculture Organization |access-date=January 18, 2014 |archive-date=March 12, 2015 |archive-url=https://web.archive.org/web/20150312075816/http://www.fao.org/docrep/w9900e/w9900e02.htm |url-status=live }}</ref> Japan captured 4,074,580 metric tons of fish in 2005, down from 4,987,703 tons in 2000 and 9,864,422 tons in 1980.<ref name="Fish capture by country">{{cite web |url=https://www.theguardian.com/environment/datablog/2009/sep/02/fish-capture-country |title=Fish capture by country |website=The Guardian |date=September 2, 2003 |access-date=January 18, 2014 |last=Brown |first=Felicity |archive-date=January 18, 2017 |archive-url=https://web.archive.org/web/20170118075757/https://www.theguardian.com/environment/datablog/2009/sep/02/fish-capture-country |url-status=live }}</ref> In 2003, the total aquaculture production was predicted at 1,301,437 tonnes.<ref name="Japan National Aquaculture Sector Overview">{{cite web |url=http://www.fao.org/fishery/countrysector/naso_japan/en |title=Japan National Aquaculture Sector Overview |website=FAO Fisheries & Aquaculture |access-date=2018-10-04 |archive-date=2017-01-21 |archive-url=https://web.archive.org/web/20170121134330/http://www.fao.org/fishery/countrysector/naso_japan/en |url-status=live }}</ref> In 2010, Japan's total fishery production was 4,762,469 fish.<ref name="World fisheries production, by capture and aquaculture, by country (2010)">{{cite web |url=ftp://ftp.fao.org/FI/STAT/summary/a-0a.pdf |title=World fisheries production, by capture and aquaculture, by country (2010) |website=Food and Agriculture Organization |access-date=January 18, 2014 |archive-url=https://web.archive.org/web/20170120164556/ftp://ftp.fao.org/FI/STAT/summary/a-0a.pdf |archive-date=2017-01-20 |url-status=dead |df=mdy-all}}</ref> Offshore fisheries accounted for an average of 50% of the nation's total fish catches in the late 1980s, although they experienced repeated ups and downs during that period.<ref name=loc/>

===Energy=== {{As of|2011}}, 46.1% of energy in Japan was produced from petroleum, 21.3% from coal, 21.4% from natural gas, 4.0% from nuclear power, and 3.3% from hydropower. Nuclear power is a major domestic source of energy and produced 9.2 percent of Japan's electricity {{As of|2011|lc=y}}, down from 24.9 percent the previous year.<ref>{{cite web |title=Energy |url=http://www.stat.go.jp/english/data/handbook/c0117.htm#c07 |website=Statistical Handbook of Japan 2013 |publisher=Statistics Bureau |access-date=February 14, 2014 |archive-date=November 13, 2013 |archive-url=https://web.archive.org/web/20131113221530/http://www.stat.go.jp/english/data/handbook/c0117.htm#c07 |url-status=live }}</ref> Following the 2011 Tōhoku earthquake and tsunami disaster, the nuclear reactors were shut down. Thus, Japan's industrial sector became even more dependent than before on imported fossil fuels. By May 2012, all of the country's nuclear power plants were taken offline because of ongoing public opposition following the Fukushima Daiichi nuclear disaster in March 2011, though government officials continued to try to sway public opinion in favor of returning at least some of Japan's 50 nuclear reactors to service.<ref>{{cite news |last=Tsukimori |first=Osamu |title=Japan nuclear power-free as last reactor shuts |url=https://www.reuters.com/article/us-nuclear-japan-idUSBRE84405820120505 |access-date=May 8, 2012 |work=Reuters |date=May 5, 2012 |archive-date=September 24, 2015 |archive-url=https://web.archive.org/web/20150924163821/http://www.reuters.com/article/2012/05/05/us-nuclear-japan-idUSBRE84405820120505 |url-status=live }}</ref> Shinzo Abe's government sook to restart the nuclear power plants that meet strict new safety standards and is emphasizing nuclear energy's importance as a base-load electricity source.<ref name="CIA World Factbook"/> In 2015, Japan successfully restarted one nuclear reactor at the Sendai Nuclear Power Plant in Kagoshima prefecture, and several other reactors around the country have since resumed operations. Opposition from local governments has delayed several restarts that remain pending.

Reforms of the electricity and gas sectors, including the full liberalization of Japan's energy market in April 2016 and the gas market in April 2017, constitute an important part of Prime Minister Abe's economic program.<ref name="CIA World Factbook"/>

Japan has the third-largest geothermal reserves in the world. Geothermal energy is being heavily focused on as a source of power following the Fukushima disaster. The Ministry of Economy, Trade, and Industry is exploring over 40 locations for potential geothermal energy plants.<ref>{{Cite web |url=http://www.renewableenergyworld.com/articles/print/volume-18/issue-3/features/geothermal/is-japan-the-next-boom-market-for-the-geothermal-energy-industry.html |title=Is Japan the Next Boom Market for the Geothermal Energy Industry? |last=Cichon |first=Meg |date=29 May 2015 |website=Renewable Energy World|access-date=20 October 2016|archive-date=8 August 2019|archive-url=https://web.archive.org/web/20190808114015/https://www.renewableenergyworld.com/articles/print/volume-18/issue-3/features/geothermal/is-japan-the-next-boom-market-for-the-geothermal-energy-industry.html|url-status=dead}}</ref>

On 3 July 2018, Japan's government pledged to increase renewable energy sources from 15% to 22–24%, including wind and solar, by 2030. Nuclear energy will provide 20% of the country's energy needs as an emissions-free energy source. This will help Japan meet climate change commitments.<ref>{{cite web |title=Japan aims for 24% renewable energy but keeps nuclear central |url=https://phys.org/news/2018-07-japan-aims-renewable-energy-nuclear.html |publisher=Phys.org |date=July 3, 2018| archive-url=https://web.archive.org/web/20180703120614/https://phys.org/news/2018-07-japan-aims-renewable-energy-nuclear.html|archive-date=July 3, 2018|access-date=October 3, 2018}}</ref>

==National Parks and Scenic Beauty== ===National Parks=== [[File:Jrb 2007 LakeToya Showashinzan.jpg|thumb|right|upright=1.3|Lake Tōya and Shōwa-shinzan in Shikotsu-Tōya National Park]] Japan has 34 {{nihongo|National Parks|国立公園|Kokuritsu Kōen}} and 56 {{nihongo|Quasi-National Parks|国定公園|Kokutei Kōen}} in 2019. These are designated and managed for protection and sustainable usage by the Ministry of the Environment under the {{nihongo|Natural Parks Law|自然公園法}} of 1957.<ref>{{cite web |url=http://www.env.go.jp/en/laws/nature/law_np.pdf |title=Natural Parks Act (1957) |publisher=Ministry of the Environment |access-date=1 February 2012 |archive-date=21 December 2016 |archive-url=https://web.archive.org/web/20161221172418/http://www.env.go.jp/en/laws/nature/law_np.pdf |url-status=live }}</ref> The Quasi-National Parks have slightly less beauty, size, diversity, or preservation. They are recommended for ministerial designation and managed by the prefectures under the supervision of the Ministry of the Environment.<ref>{{cite web |url=http://www.env.go.jp/en/nature/nps/park/doc/files/parksystem.pdf |title=Natural Park Systems in Japan |publisher=Ministry of the Environment |pages=4, 12 |access-date=1 February 2012 |archive-date=29 January 2013 |archive-url=https://web.archive.org/web/20130129013911/http://www.env.go.jp/en/nature/nps/park/doc/files/parksystem.pdf |url-status=live }}</ref>

The Japanese archipelago has diverse landscapes.<ref name="water-supply"/> For example, the northern part of Hokkaido has a taiga biome.<ref>C.Michael Hogan. 2011. [http://www.eoearth.org/view/article/171390/ ''Taiga''. eds. M.McGinley & C.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC] {{Webarchive|url=https://web.archive.org/web/20131104122600/http://www.eoearth.org/view/article/171390/ |date=2013-11-04 }}</ref> Hokkaido has 22% of Japan's forestland with coniferous trees (Sakhalin fir and Sakhalin spruce) and broad-leaved trees (Japanese oak, birch, and painted maple). The seasonal views change throughout the year.<ref>{{Cite web |url=http://www.rinya.maff.go.jp/hokkaido/koho/koho_net/library/pdf/national_forest_in_hokkaido.pdf |title=National Forests in Hokkaido |date=2014-03-01 |website=Ministry of Agriculture, Forestry and Fisheries |publisher=Hokkaido Regional Forest Office |language=ja|archive-url=https://web.archive.org/web/20180627115721/http://www.rinya.maff.go.jp/hokkaido/koho/koho_net/library/pdf/national_forest_in_hokkaido.pdf|archive-date=2018-06-27|access-date=2019-07-21}}</ref> In the south, the Yaeyama Islands are in the subtropics, with numerous species of subtropical and tropical plants and mangrove forests.<ref name="c">{{cite encyclopedia |encyclopedia=Nihon Rekishi Chimei Taikei |title=八重山諸島 |url=http://rekishi.jkn21.com/ | access-date = 2012-12-04 |year=2012 |publisher=Shogakukan |location=Tokyo |language=ja | trans-title = Yaeyama Islands |oclc=173191044 | archive-url = https://web.archive.org/web/20070825113418/http://rekishi.jkn21.com/ | archive-date = 2007-08-25 | url-status = dead}}</ref><ref>{{Cite web |url=https://www.pref.okinawa.jp/okinawa_kankyo/shizen_hogo/hozen_chiiki/shishin/yaeyama_hozen_shishin/yaeyama_riku_shizen2.html |title=自然環境の保全に関する指針八重山編（陸域） |website=Okinawa Prefectural Government |language=ja |trans-title=Guidelines for conservation of the natural environment |access-date=2019-01-15 |archive-date=2016-04-05 |archive-url=https://web.archive.org/web/20160405084024/http://www.pref.okinawa.jp/okinawa_kankyo/shizen_hogo/hozen_chiiki/shishin/yaeyama_hozen_shishin/yaeyama_riku_shizen2.html |url-status=live }}</ref> Most natural islands have mountain ranges in the center and coastal plains. * List of National Parks of Japan * List of National Geoparks in Japan * Wildlife Protection Areas in Japan * List of Ramsar sites in Japan * Cultural Landscapes

===Places of Scenic Beauty=== [[File:Ritsurin_park16s3200.jpg|thumb|Ritsurin Garden, Takamatsu, Japan]] The Places of Scenic Beauty and Natural Monuments are selected by the government via the Agency for Cultural Affairs in order to protect Japan's cultural heritage.<ref>{{cite web |url=http://www.bunka.go.jp/koho_hodo_oshirase/hodohappyo/__icsFiles/afieldfile/2017/11/15/a1397922_01.pdf |script-title=ja:史跡等の指定等について |trans-title=Designation of Special Historic Sites |author= |date=2017-09-14 |website=Agency for Cultural Affairs |access-date=2017-11-18 |archive-date=2017-12-01 |archive-url=https://web.archive.org/web/20171201033530/http://www.bunka.go.jp/koho_hodo_oshirase/hodohappyo/__icsFiles/afieldfile/2017/11/15/a1397922_01.pdf |url-status=dead}}</ref> As of 2017, there are 1,027 {{nihongo|Natural Monuments|天然記念物|tennen kinenbutsu}} and 410 {{nihongo|Places of Scenic Beauty|名勝|meishō}}. The highest classifications are 75 {{nihongo|Special Natural Monuments|特別天然記念物|tokubetsu tennen kinenbutsu}} and 36 {{nihongo|Special Places of Scenic Beauty|特別名勝|tokubetsu meishō}}.

===Three Views of Japan=== The {{nihongo|Three Views of Japan|日本三景|Nihon Sankei}} is the canonical list of Japan's three most celebrated scenic sights, attributed to 1643 scholar Hayashi Gahō.<ref>{{cite web |url=http://www.amanohashidate.jp/rekishi.html |title=Amanohashidate – History |publisher=Amanohashidate kankokyokai |access-date=14 May 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110717114213/http://www.amanohashidate.jp/rekishi.html |archive-date=17 July 2011}}</ref> These are traditionally the pine-clad islands of Matsushima in Miyagi Prefecture, the pine-clad sandbar of Amanohashidate in Kyoto Prefecture, and Itsukushima Shrine in Hiroshima Prefecture. In 1915, the New Three Views of Japan were selected in a national election by the Jitsugyo no Nihon Sha (株式会社実業之日本社). In 2003, the Three Major Night Views of Japan were selected by the ''New Three Major Night Views of Japan and the 100 Night Views of Japan Club'' (新日本三大夜景・夜景100選事務局).

<gallery> Matsushima miyagi z.JPG|Pine-clad islands of Matsushima Amanohashidate view from Mt Moju02s3s4592.jpg|Sandbar of Amanohashidate 20131012_07_Miyajima_-_Torii_(10491662566).jpg|Torii at Itsukushima Shrine </gallery>

==Climate== {{main|climate of Japan}} [[File:Koppen-Geiger_Map_v2_JPN_1991–2020.svg|thumb|upright=2|A Köppen climate classification map of Japan]] Most regions of Japan, such as much of Honshu, Shikoku, and Kyushu, belong to the temperate zone with a humid subtropical climate (Köppen climate classification ''Cfa'') characterized by four distinct seasons. However, its climate varies from a cool, humid continental climate (Köppen climate classification ''Dfa''/''Dfb'') in the north, such as northern Hokkaido, to a warm tropical rainforest climate (Köppen climate classification ''Af'') in the south, such as the Yaeyama Islands and Minami-Tori-shima. Japan's varied geographical features divide it into six principal climatic zones: Hokkaido, Sea of Japan, Central Highland, Seto Inland Sea, Pacific Ocean, and Ryukyu Islands.<ref>{{Cite journal |title=中学校社会科・地理的分野における「気候」の扱いに関する一考察 |url=https://nfu.repo.nii.ac.jp/records/2000080 |accessdate=2013-12-09 |publisher=日本福祉大学教育・心理学部 |language=ja |journal=日本福祉大学子ども発達学論集 |date=2024-02-14 |issue=16 }}</ref> The highest recorded temperature in Japan was 41.8 °C (107.2 °F) on 5 August 2025, and the lowest was −41.0 °C (−41.8 °F) in Asahikawa on 25 January 1902.<ref>{{cite web |author1=気象庁 |title=歴代全国ランキング |url=https://www.data.jma.go.jp/stats/etrn/view/rankall.php |website=www.data.jma.go.jp |accessdate=2025-12-29}}</ref>

==Population distribution== {{Main|Demographics of Japan}} {{see also|List of cities in Japan}} thumb|upright=2|A map of Japan's major cities, main towns and selected smaller centers Japan has a population of 126.3 million in 2019.<ref name="SBJ-Population-June-2019">{{cite web |url=http://www.stat.go.jp/english/data/jinsui/tsuki/index.html |title=Population Estimates Monthly Report June 2019 |date=June 20, 2019 |website=www.stat.go.jp |publisher=Statistics Bureau Japan|access-date=July 18, 2019 | archive-url=https://web.archive.org/web/20190606203315/http://www.stat.go.jp/english/data/jinsui/tsuki/index.html |archive-date= June 6, 2019}}</ref> It is the eleventh-most populous country and the second-most populous island country in the world.<ref name="world-atlas"/> The population is clustered in urban areas along the coast, plains, and valleys.<ref name="autogenerated1"/> In 2010, 90.7% of the total Japanese population lived in cities.<ref>{{cite web |title=平成22年国勢調査最終報告書人口の地域分布 |url=http://www.stat.go.jp/data/kokusei/2010/final/pdf/01-02.pdf |publisher=The Ministry of Internal Affairs and Communications Statistics Bureau |access-date=2015-10-14 |archive-date=2018-11-19 |archive-url=https://web.archive.org/web/20181119105951/http://www.stat.go.jp/data/kokusei/2010/final/pdf/01-02.pdf |url-status=live }}</ref> Japan is an urban society, with about 5% of the labor force working in agriculture. About 80 million of the urban population is heavily concentrated on the Pacific coast of Honshu.<ref name="jpn-places">{{cite web|url=https://www.loc.gov/today/placesinthenews/archive/2011arch/20110921_japan.html|title=Japan – Places in the News {{!}} Library of Congress|website=www.loc.gov|access-date=2017-01-30|archive-date=2017-02-02|archive-url=https://web.archive.org/web/20170202062725/https://www.loc.gov/today/placesinthenews/archive/2011arch/20110921_japan.html|url-status=live}}</ref>

81% of the population lives on Honshu, 10% on Kyushu, 4.2% on Hokkaido, 3% on Shikoku, 1.1% in Okinawa Prefecture, and 0.7% on other Japanese islands such as the Nanpō Islands. Nearly 1 in 3 Japanese people live in the Greater Tokyo Area, and over half live in the Kanto, Kinki, and Chukyo metropolitan areas.<ref>{{Cite web |last=Statistics Bureau of Japan |title=Statistical Handbook of Japan 2020 |url=https://www.stat.go.jp/english/data/handbook/pdf/2020all.pdf#page=21 |access-date=2021-04-19 |archive-date=2021-04-19 |archive-url=https://web.archive.org/web/20210419061817/https://www.stat.go.jp/english/data/handbook/pdf/2020all.pdf#page=21 |url-status=live }}</ref>

===Honshu=== {{nihongo|''Honshū''|本州}} is the largest island of Japan and the second most populous island in the world. It has a population of 104,000,000 with a population density of {{Pop density|447|1|km2|sqmi}} (2010).<ref name="JPCensus">{{cite web |url=http://www.soumu.go.jp/main_sosiki/jichi_gyousei/c-gyousei/daityo/index.html |title=総務省{{pipe}}住基ネット |work=soumu.go.jp |access-date=2018-10-21 |archive-date=2021-02-24 |archive-url=https://web.archive.org/web/20210224144613/https://www.soumu.go.jp/main_sosiki/jichi_gyousei/c-gyousei/daityo/index.html |url-status=live }}</ref> Honshu is roughly {{convert|1300|km|abbr=on}} long and ranges from {{convert|50|to|230|km|mi|abbr=on}} wide, and the total area is {{convert|225,800|km2|sqmi|abbr=on}}. It is the 7th largest island in the world.<ref name="autogenerated5">{{cite web |url=http://islands.unep.ch/Tiarea.htm |title=Islands By Land Area |publisher=Islands.unep.ch |access-date=2010-08-01 |archive-date=2018-02-20 |archive-url=https://web.archive.org/web/20180220003634/http://islands.unep.ch/Tiarea.htm |url-status=dead}}</ref> This makes it slightly larger than the island of Great Britain ({{convert|209,331|km2|sqmi|abbr=on}}).<ref name="autogenerated5"/>

The Greater Tokyo Area on Honshu is the largest metropolitan area (megacity) in the world, with {{nts|38,140,000}} people (2016).<ref name="japan1">{{cite web |url=http://www.stat.go.jp/english/data/handbook/c0117.htm |title=Table 2.10 Population of Three Major Metropolitan Areas |publisher=Statistics Bureau of Japan |access-date=26 November 2013 |archive-date=13 November 2013 |archive-url=https://web.archive.org/web/20131113221530/http://www.stat.go.jp/english/data/handbook/c0117.htm |url-status=live }}</ref><ref>{{cite web |url=https://www.un.org/en/development/desa/population/publications/pdf/urbanization/the_worlds_cities_in_2016_data_booklet.pdf |title=The World's Cities in 2016 |last=United Nations |date=March 12, 2017 |website=United Nations |access-date=October 20, 2018 |archive-date=January 12, 2017 |archive-url=https://web.archive.org/web/20170112211410/http://www.un.org/en/development/desa/population/publications/pdf/urbanization/the_worlds_cities_in_2016_data_booklet.pdf |url-status=live }}</ref> The area is {{convert|13,500|km2|sqmi|abbr=on}}<ref name=MMA>[http://www.stat.go.jp/data/kokusei/2000/final/zuhyou/092.xls Japan Statistics Bureau – Keihin'yō Major Metropolitan Area] {{webarchive|url=https://web.archive.org/web/20070210012525/http://www.stat.go.jp/data/kokusei/2000/final/zuhyou/092.xls |date=2007-02-10 }}</ref> and has a population density of 2,642 persons/km2.<ref>{{Citation |title=Demographia World Urban Areas: 12th Annual Edition: 2016:04 |date=2016 |url=http://demographia.com/db-worldua.pdf|archive-url=https://web.archive.org/web/20161013155105/http://demographia.com/db-worldua.pdf |publisher=Demographia|access-date=2007-05-10|archive-date=2016-10-13|url-status=dead}}</ref>

===Kyushu=== {{nihongo|''Kyushu''|九州}} is the third-largest island of Japan of the five main islands.<ref name="main-islands-japan"/><ref>Nussbaum, Louis-Frédéric. (2005). "Kyūshū" in {{Google books|p2QnPijAEmEC|''Japan Encyclopedia'', p. 588|page=588}}</ref> {{As of|2016}}, Kyushu has a population of 12,970,479 and covers {{convert|36782|km2|sqmi|abbr=on}}.<ref>{{Cite news |url=https://www.thoughtco.com/islands-of-japan-1435071 |title=Discover the Geography of the 4 Main Islands of Japan |work=ThoughtCo |access-date=2018-09-26 |archive-date=2018-09-26 |archive-url=https://web.archive.org/web/20180926205952/https://www.thoughtco.com/islands-of-japan-1435071 |url-status=live }}</ref> It has the second-highest population density of 307.13 persons/km2 (2016).

===Shikoku=== {{nihongo|''Shikoku''|四国}} is the second-smallest of the five main islands (after Okinawa Island), with {{convert|18,800|km2|sqmi|abbr=on}}. It is located south of Honshu and northeast of Kyushu. It has the second-smallest population of 3,845,534 (2015)<ref name="main-islands-japan"/><ref name=tourism>{{cite web |url=http://www.jnto.go.jp/eng/location/rtg/pdf/pg-607.pdf |title=Shikoku and Awaji Island |publisher=Japan National Tourism Organization |date=September 2011 |access-date=2013-05-02 |url-status=live |archive-url=https://web.archive.org/web/20130204132833/http://www.jnto.go.jp/eng/location/rtg/pdf/pg-607.pdf |archive-date=2013-02-04}}</ref> and the third-highest population density of 204.55 persons/km2.

===Hokkaido=== {{nihongo|''Hokkaido''|北海道}} is the second-largest island of Japan and the largest and northernmost prefecture. The Tsugaru Strait separates Hokkaido from Honshu.<ref name="nussbaum343">Nussbaum, Louis-Frédéric. (2005). "Hokkaido" in {{Google books|p2QnPijAEmEC|''Japan Encyclopedia'', p. 343|page=343}}</ref> It has the third largest population of the five main islands, with 5,383,579 (2015),<ref name="main-islands-japan"/><ref name="JPCensus"/> and the lowest population density, with just 64.5 persons/km2 (2016). The island area ranks 21st in the world by area. It is 3.6% smaller than the island of Ireland.

===Okinawa Prefecture=== {{nihongo|''Okinawa Prefecture''|沖縄県}} is the southernmost prefecture of Japan.<ref>Nussbaum, Louis-Frédéric. (2005). "Okinawa-shi" in {{Google books|p2QnPijAEmEC|''Japan Encyclopedia'', p. 746-747|page=746}}</ref> It encompasses two-thirds of the Ryukyu Islands, over {{convert|1000|km}} long. It has a population of 1,445,812 (2017) and a density of 662 persons/km2. {{nihongo|''Okinawa Island''|沖縄本島 or 沖縄島}} is the smallest and most southwestern of the five main islands, at {{convert|1,206.98|km2|sqmi|abbr=on}}.<ref name="main-islands-japan"/> It has the smallest population of 1,301,462 (2014) and the highest population density of 1083.6 persons/km2.

===Nanpō Islands=== {{nihongo|''Nanpō Islands''|南方諸島}} are the groups of islands that are located to the south and east of the main islands of the Japanese archipelago. They extend from the Izu Peninsula west of Tokyo Bay southward for about {{convert|1,200|km}} to within {{convert|500|km}} of the Mariana Islands. The Nanpō Islands are all administered by Tokyo Metropolis.

===Taiheiyō Belt=== [[File:Major_metropolitan_employment_areas_of_Taiheiyō_Belt.svg|thumb|upright=1.2|right|Taiheiyō Belt]] The Taiheiyō Belt is a megalopolis that includes the Greater Tokyo Area and Keihanshin megapoles. It is almost {{convert|1,200|km|mi|abbr=on}} long, from Ibaraki Prefecture in the northeast to Fukuoka Prefecture in the southwest. Satellite images at night show a dense and continuous strip of light (demarcating urban zones) that delineates the region with overlapping metropolitan areas in Japan.<ref>{{Cite web |url=http://agora.ex.nii.ac.jp/~kitamoto/research/rs/world-lights.html.en |title=Satellite images of stable night time lights in Japan |access-date=2018-10-20 |archive-date=2006-02-16 |archive-url=https://web.archive.org/web/20060216012218/http://agora.ex.nii.ac.jp/~kitamoto/research/rs/world-lights.html.en |url-status=live }}</ref> It has a total population of approximately 81,859,345 (2016). * Taiheiyō Belt – includes Ibaraki, Saitama, Chiba, Tokyo, Kanagawa, Shizuoka, Aichi, Gifu, Mie, Kyoto, Osaka, Hyōgo, Wakayama, Okayama, Hiroshima, Yamaguchi, Fukuoka, and Ōita. (81,859,345 people)<ref>{{cite web |url=http://www.meti.go.jp/committee/materials/downloadfiles/g60519c03j.pdf#page=4 |title=地域活性化戦略（案）資料 |publisher=Ministry of Economy, Trade and Industry|access-date=August 13, 2016 |format=PDF |language=ja |page=4|archive-url=https://web.archive.org/web/20160923151046/http://www.meti.go.jp/committee/materials/downloadfiles/g60519c03j.pdf#page=4|archive-date=September 23, 2016|url-status=live |df=mdy-all}}</ref><ref>{{cite web |title=2015 Population Census |url=http://www.stat.go.jp/english/data/kokusei/2015/summary.htm |publisher=Statistics Bureau, Ministry of Internal Affairs and Communications|access-date=August 13, 2016|archive-url=https://web.archive.org/web/20160825120347/http://www.stat.go.jp/english/data/kokusei/2015/summary.htm|archive-date=August 25, 2016|url-status=live |df=mdy-all}}</ref> ** Greater Tokyo Area – Part of the larger Kantō region, broadly includes Tokyo and Yokohama. (38,000,000 people)<ref>United Nations (March 12, 2017). "[https://www.un.org/en/development/desa/population/publications/pdf/urbanization/the_worlds_cities_in_2016_data_booklet.pdf The World's Cities in 2016] {{Webarchive|url=https://web.archive.org/web/20170112211410/http://www.un.org/en/development/desa/population/publications/pdf/urbanization/the_worlds_cities_in_2016_data_booklet.pdf |date=2017-01-12 }}" (PDF). United Nations</ref> ** Keihanshin – Part of the larger Kansai region, includes Osaka, Kyoto, and Kobe. (19,341,976 people)<ref>[http://www.stat.go.jp/data/nenkan/back60/zuhyou/y0206000.xls Japan Statistics Bureau] {{Webarchive|url=https://web.archive.org/web/20150924120320/http://www.stat.go.jp/data/nenkan/back60/zuhyou/y0206000.xls |date=2015-09-24 }} – "2010 Census", retrieved August 23, 2015</ref>

===Underwater habitats=== There are plans to build underwater habitats in Japan's Exclusive Economic Zone. Currently no underwater city is constructed yet. For example, the Ocean Spiral by Shimizu Corporation would have a floating dome 500 meters in diameter with hotels, residential and commercial complexes. It could be 15 km long. This allows mining of the seabed, research and production of methane from carbon dioxide with micro-organisms. The Ocean Spiral was co-developed with JAMSTEC and Tokyo University.<ref>{{cite web |url=http://www.shimz.co.jp/theme/dream/oceanspiral.html |title=Ocean Spiral |access-date=November 21, 2014 |language=ja |archive-date=November 23, 2014 |archive-url=https://web.archive.org/web/20141123072243/http://www.shimz.co.jp/theme/dream/oceanspiral.html |url-status=live }}</ref><ref>{{cite news |url=https://www.telegraph.co.uk/news/worldnews/asia/japan/11244758/City-of-the-future-sinks-into-the-ocean.html |title=City of the future sinks into the ocean |newspaper=Daily Telegraph |access-date=November 21, 2014 |archive-url=https://web.archive.org/web/20180908021259/https://www.telegraph.co.uk/news/worldnews/asia/japan/11244758/City-of-the-future-sinks-into-the-ocean.html |archive-date = September 8, 2018}}</ref>

Japan extends from 20° to 45° north latitude (Okinotorishima to Benten-jima) and from 122° to 153° east longitude (Yonaguni to Minami Torishima).<ref name="geohack">{{cite web |url=https://tools.wmflabs.org/geohack/geohack.php?pagename=Geography_of_Japan&params=36_N_138_E_type:country |title=GeoHack – Geography of Japan |publisher=GeoHack |access-date=October 14, 2018 |archive-date=April 15, 2020 |archive-url=https://web.archive.org/web/20200415133454/https://tools.wmflabs.org/geohack/geohack.php?pagename=Geography_of_Japan&params=36_N_138_E_type:country |url-status=live }}</ref> These are the points that are farther north, south, east, or west than any other location in Japan.

{| class="wikitable" style="width:75%;" |- ! style="width:10%;"| Heading ! style="width:15%;"| Location ! style="width:10%;"| Prefecture ! style="width:15%;"| Bordering entity ! style="width:20%;" class="unsortable"| Coordinates{{ref|coord|†}} ! style="width:5%;" class="unsortable"| Ref |- class="vcard" | North (disputed) | class="fn org" | Cape Kamoiwakka on Etorofu | Hokkaido{{ref|iturup|‡}} | Sea of Okhotsk | {{coord|45|33|26|N|148|45|09|E|region:JP-01_type:landmark|name=Cape Kamoiwakka (Northernmost – disputed)}} | <ref>{{cite web |url=https://maps.google.com/maps?ll=45.557187,148.752367&q=45.557187,148.752367&t=h&z=15 |title=Google Maps (Cape Kamoiwakka) |work=Google|access-date=2009-07-29}}</ref> |- class="vcard" | North (undisputed) | class="fn org" | Benten-jima | Hokkaido | La Pérouse Strait | {{coord|45|31|38|N|141|55|06|E|region:JP-01_type:landmark|name=Bentenjima (Northernmost – undisputed)}} | <ref>{{cite web |url=https://maps.google.com/maps?ll=45.527336,141.918211&q=45.527336,141.918211&t=h&z=13 |title=Google Maps (Bentenjima) |work=Google|access-date=2009-07-29}}</ref> |- class="vcard" | South | class="fn org" | Okinotorishima | Tokyo | Philippine Sea | {{coord|20|25|31|N|136|04|11|E|region:JP-13_type:landmark|name=Okinotorishima (Southernmost)}} | |- class="vcard" | East | class="fn org" | Minami Torishima | Tokyo | Pacific Ocean | {{coord|24|16|59|N|153|59|11|E|region:JP-13_type:landmark|name=Minami Torishima (Easternmost)}} | |- class="vcard" | West | class="fn org" | Yonaguni | Okinawa | East China Sea | {{coord|24|26|58|N|122|56|01|E|region:JP-47_type:landmark|name= (Westernmost)}} | The westernmost Monument of Japan |}

===Japan's main islands=== The five main islands of Japan are Hokkaido, Honshū, Kyūshū, Shikoku, and Okinawa. These are also called the mainland.<ref name="main-islands-japan"/> All of these points are accessible to the public.

===Extreme altitudes=== {| class="wikitable sortable" style="width:75%;" |- ! style="width:12%;" class="unsortable"| Extremity ! style="width:15%;"| Name ! style="width:13%;"| Altitude ! style="width:7%;" class="unsortable"| Prefecture ! style="width:25%;" class="unsortable"| Coordinates{{ref|coord|†}} ! style="width:5%;" class="unsortable"| Ref |- class="vcard" | Highest | class="fn org" | Mount Fuji | {{convert|3776|m|ft|0|abbr=on}} | Yamanashi | {{coord|35|21|29|N|138|43|52|E|region:JP-19_type:mountain|name=Mount Fuji (Highest)}} | <ref name="CIA World Factbook"/> |- class="vcard" | Lowest (human-made) | class="fn org" | Hachinohe mine | −170 m (−558 ft) | Aomori | {{coord|40|27|10|N|141|32|16|E|region:JP-02_type:landmark|name=Hachinohe mine (Lowest – man-made)}} | <ref name="mine">{{cite web |url=http://www.iceee.jp/sisetudb/prev.php?id=367 |script-title=ja:施設見学ガイド八戸鉱山株式会社八戸石灰鉱山(八戸キャニオン) |access-date=2016-04-06 |work=The Information Center for Energy and Environment Education |language=ja |archive-date=2016-04-17 |archive-url=https://web.archive.org/web/20160417025218/http://www.iceee.jp/sisetudb/prev.php?id=367 |url-status=dead}}</ref> |- class="vcard" | Lowest (natural) | class="fn org" | Hachirōgata | −4 m (−13 ft) | Akita | {{coord|39|54|50|N|140|01|15|E|region:JP-05_type:landmark|name=Hachirōgata (Lowest – natural)}} | <ref name="CIA World Factbook"/> |}

{{main|List of islands of Japan|List of islands of Japan by area|Japanese archipelago}}

These are the 50 largest islands of Japan. It excludes the disputed Kuril Islands, known as the northern territories.

{| class="sortable wikitable" |- ! Rank !! Island name !! | Area (km2) !! Area (sq mi) !! Island group |- | 1 ||Honshu|| 227,960 ||{{convert|227,960|km2|disp=number}}|| |- | 2 || Hokkaido || 83,424.31 || {{convert|83,424.31|km2|disp=number}} || |- | 3 || Kyushu || 36,782 || {{convert|36,782|km2|disp=number}} || |- | 4 || Shikoku || 18,800 || {{convert|18,800|km2|disp=number}} || |- | 5 || Okinawa Island || 1,207 || {{convert|1,207|km2|disp=number}} || Ryukyu Islands |- | 6 || Sado Island || 855.26 || {{convert|855.26|km2|disp=number}} || |- | 7 || Amami Ōshima || 712.35 || {{convert|712.35|km2|disp=number}} || Amami Islands |- | 8 || Tsushima Island || 708.7|| {{convert|708.7|km2|disp=number}} || |- | 9 || Awaji Island || 592.17|| {{convert|592.17|km2|disp=number}} || |- | 10 || Shimoshima Island, Amakusa || 574.01|| {{convert|574.01|km2|disp=number}} || |- | 11 || Yakushima || 504.88 || {{convert|504.88|km2|disp=number}} || Ōsumi Islands |- | 12 || Tanegashima || 444.99 || {{convert|444.99|km2|disp=number}} || Ōsumi Islands |- | 13 || Fukue Island || 326.43 || {{convert|326.43|km2|disp=number}} || Gotō Islands |- | 14 || Iriomote Island || 289.27 || {{convert|289.27|km2|disp=number}} || |- | 15 || Tokunoshima || 247.8 || {{convert|247.8|km2|disp=number}} || |- | 16 || Dōgojima || 241.58 || {{convert|241.58|km2|disp=number}} || Oki Islands |- | 17 || Kamishima Island, Amakusa || 225.32 || {{convert|225.32|km2|disp=number}} || Amakusa islands |- | 18 || Ishigaki Island || 222.5 || {{convert|222.5|km2|disp=number}} || |- | 19 || Rishiri Island || 183 || {{convert|183|km2|disp=number}} || |- | 20 || Nakadōri Island || 168.34 || {{convert|168.34|km2|disp=number}} || Gotō Islands |- | 21 || Hirado Island || 163.42 || {{convert|163.42|km2|disp=number}} || |- | 22 || Miyako-jima || 158.87 || {{convert|158.87|km2|disp=number}} || |- | 23 || Shōdoshima || 153.30 || {{convert|153.30|km2|disp=number}} || |- | 24 || Okushiri Island || 142.97 || {{convert|142.97|km2|disp=number}} || |- | 25 || Iki Island || 138.46|| {{convert|138.46|km2|disp=number}} || |- | 26 || Suō-Ōshima || 128.31|| {{convert|128.31|km2|disp=number}} || |- | 27 || Okinoerabujima || 93.63 || {{convert|93.63|km2|disp=number}} || |- | 28 || Etajima || 91.32 || {{convert|91.32|km2|disp=number}} || |- | 29 || Izu Ōshima || 91.06 || {{convert|91.06|km2|disp=number}} || Izu Islands |- | 30 || Nagashima Island, Kagoshima || 90.62 || {{convert|90.62|km2|disp=number}} || |- | 31 || Rebun Island || 80 || {{convert|80|km2|disp=number}} || |- | 32 || Kakeromajima || 77.39 || {{convert|77.39|km2|disp=number}} || |- | 33 || Kurahashi-jima || 69.46 || {{convert|69.46|km2|disp=number}} || |- | 34 || Shimokoshiki-jima || 66.12 || {{convert|66.12|km2|disp=number}} || |- | 35 || Ōmishima Island, Ehime || 66.12 || {{convert|66.12|km2|disp=number}} || |- | 36 || Hachijō-jima || 62.52 || {{convert|62.52|km2|disp=number}} || |- | 37 || Kume Island || 59.11 || {{convert|59.11|km2|disp=number}} || Okinawa Islands |- | 38 || Kikaijima || 56.93 || {{convert|56.93|km2|disp=number}} || Amami Islands |- | 39 || Nishinoshima || 55.98 || {{convert|55.98|km2|disp=number}} || |- | 40 || Miyake-jima || 55.44 || {{convert|55.44|km2|disp=number}} || |- | 41 || Notojima || 46.78 || {{convert|46.78|km2|disp=number}} || |- | 42 || Kamikoshiki-jima || 45.08 || {{convert|45.08|km2|disp=number}} || |- | 43 || Ōshima (Ehime) || 41.87 || {{convert|41.87|km2|disp=number}} || |- | 44 || Ōsakikamijima || 38.27 || {{convert|38.27|km2|disp=number}} || |- | 45 || Kuchinoerabu-jima || 38.04 || {{convert|38.04|km2|disp=number}} || |- | 46 || Hisaka || 37.23 || {{convert|37.23|km2|disp=number}} || |- | 47 || Innoshima || 35.03 || {{convert|35.03|km2|disp=number}} || |- | 48 || Nakanoshima (in Kagoshima) || 34.47 || {{convert|34.47|km2|disp=number}} || Tokara Islands |- | 49 || Hario Island || 33.16 || {{convert|33.16|km2|disp=number}} || |- | 50 || Nakanoshima (in Shimane) || 32.21 || {{convert|32.21|km2|disp=number}} || Oki Islands |}

===Northern Territories=== upright=1.25|thumb|The Kuril Islands, with their Russian names. The borders of the Treaty of Shimoda (1855) and the Treaty of St. Petersburg (1875) are shown in red. Currently, all islands northeast of Hokkaido are administered by Russia. {{Main|Kuril Islands dispute}} Japan has a longstanding claim to the Southern Kuril Islands (Etorofu, Kunashiri, Shikotan, and the Habomai Islands). These islands were occupied by the Soviet Union in 1945.<ref>MOFA, [http://www.mofa.go.jp/region/europe/russia/territory/index.html Japan's Northern Territories] {{Webarchive|url=https://web.archive.org/web/20110322191810/http://www.mofa.go.jp/region/europe/russia/territory/index.html |date=2011-03-22 }}</ref> The Kuril Islands historically belonged to Japan.<ref>{{cite book |last=Peattie |first=Mark R. |title=The Cambridge History of Japan Vol. 6 |chapter=Chapter 5 – The Japanese Colonial Empire 1895–1945 |publisher=Cambridge University Press |year=1988 |location=Cambridge |isbn=0-521-22352-0}}</ref> The Kuril Islands were first inhabited by the Ainu people and then controlled by the Japanese Matsumae clan in the Edo Period.<ref>{{Cite book |title=The Kuril Islands |first=John J |last=Stephan |publisher=Clarendon Press |location=Oxford |year=1974 |pages=50–56}}</ref> The Soviet Union did not sign the San Francisco Treaty in 1951. The U.S. Senate Resolution of April 28, 1952, ratifying the San Francisco Treaty, explicitly stated that the USSR had no title to the Kurils.<ref name="goodby">James E. Goodby, Vladimir I. Ivanov, Nobuo Shimotomai, ''Northern territories and beyond: Russian, Japanese, and American Perspectives'', Praeger Publishers, 1995</ref> This dispute has prevented the signing of a peace treaty between Japan and Russia.

Geographically, the Kuril Islands are a northeastern extension of Hokkaido. Kunashiri and the Habomai Islands are visible from the northeastern coast of Hokkaido. Japan considers the northern territories (aka Southern Chishima) part of the Nemuro Subprefecture of Hokkaido Prefecture.

==Time zone== {{main|Japan Standard Time}}

There is one time zone in the whole Japanese archipelago. It is 9 hours ahead of UTC.<ref>{{cite web |url=https://www.timeanddate.com/worldclock/japan |title=Current Local Time in Japan |website=timeanddate.com |access-date=2020-01-23 |archive-date=2021-03-24 |archive-url=https://web.archive.org/web/20210324201303/https://www.timeanddate.com/worldclock/japan |url-status=live }}</ref> There is no daylight saving time. The easternmost Japanese island, Minami-Tori-shima, also uses Japan Standard Time, while it is geographically {{convert|1848|km|mi|0}} southeast of Tokyo and in the UTC+10:00 time zone.

Sakhalin uses UTC+11:00, even though it is located directly north of Hokkaido. The Northern Territories and the Kuril Islands use UTC+11:00, although they are geographically in UTC+10:00.

==Natural hazards== ===Earthquakes and tsunami=== [[File:SH-60B helicopter flies over Sendai.jpg|thumb|The aftermath of the 2011 Tōhoku earthquake and tsunami]] {{see also|List of earthquakes in Japan}} Japan is substantially prone to earthquakes, tsunamis, and volcanoes because of its location along the Pacific Ring of Fire.<ref>{{cite web |url=http://www.livescience.com/30226-japan-tectonics-explosive-geology-ring-of-fire-110314.html |title=Japan's Explosive Geology Explained |publisher=Live Science |last=Israel |first=Brett |date=March 14, 2011 |access-date=June 17, 2016 |archive-date=August 5, 2019 |archive-url=https://web.archive.org/web/20190805085127/https://www.livescience.com/30226-japan-tectonics-explosive-geology-ring-of-fire-110314.html |url-status=live }}</ref> It has the 15th highest natural disaster risk as measured in the 2013 World Risk Index.<ref name="2013 World Risk Report">[http://www.worldriskreport.com/uploads/media/WorldRiskReport_2013_online_01.pdf 2013 World Risk Report] {{webarchive |url=https://web.archive.org/web/20140816173655/http://www.worldriskreport.com/uploads/media/WorldRiskReport_2013_online_01.pdf |date=August 16, 2014 }}</ref>

As many as 1,500 earthquakes are recorded yearly, and magnitudes of 4 to 6 are common.<ref name=loc/> Minor tremors occur almost daily in one part of the country or another, causing slight shaking of buildings.<ref name=loc/> Undersea earthquakes also expose the Japanese coastline to danger from {{nihongo|tsunamis|津波}}.<ref name=loc/>

Destructive earthquakes, often resulting in tsunamis, occur several times each century.<ref name="volcanoes-japan" /> The 1923 Tokyo earthquake killed over 140,000 people.<ref>{{cite web |last=James |first=C.D. |title=The 1923 Tokyo Earthquake and Fire |url=http://nisee.berkeley.edu/kanto/tokyo1923.pdf |publisher=University of California Berkeley |access-date=January 16, 2011 |year=2002 |url-status=dead |archive-url=https://web.archive.org/web/20070316050633/http://nisee.berkeley.edu/kanto/tokyo1923.pdf |archive-date=March 16, 2007}}</ref> More recent major quakes are the 1995 Great Hanshin earthquake and the 2011 Tōhoku earthquake, a 9.1-magnitude<ref name="USGS9.1">{{cite web |url=https://earthquake.usgs.gov/earthquakes/eventpage/official20110311054624120_30#executive |title=M 9.1 – near the east coast of Honshu, Japan |publisher=Earthquake.usgs.gov |date=July 11, 2016 |access-date=August 29, 2017 |archive-date=April 7, 2011 |archive-url=https://web.archive.org/web/20110407005101/http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/#executive |url-status=live }}</ref> quake that hit Japan on March 11, 2011. It triggered a large tsunami and the Fukushima Daiichi nuclear disaster, one of the worst disasters in the history of nuclear power.<ref name="nytimes-tsunami">{{cite news |last1=Fackler |first1=Martin |last2=Drew |first2=Kevin |title=Devastation as Tsunami Crashes Into Japan |url=https://www.nytimes.com/2011/03/12/world/asia/12japan.html?ref=world |access-date=March 11, 2011 |work=The New York Times |date=March 11, 2011 |archive-date=July 28, 2018 |archive-url=https://web.archive.org/web/20180728101451/https://www.nytimes.com/2011/03/12/world/asia/12japan.html?ref=world |url-status=live }}</ref>

The 2011 Tōhoku earthquake was the largest ever recorded in Japan and is the world's fourth largest earthquake to strike since 1900, according to the U.S. Geological Service. It struck offshore about {{convert|371|km|mi}} northeast of Tokyo and {{convert|130|km|mi}} east of the city of Sendai and created a massive tsunami that devastated Japan's northeastern coastal areas. At least 100 aftershocks registering a magnitude of 6.0 or higher have followed the main shock. At least 15,000 people died as a result.

Researchers found the source of great thrust earthquakes and associated tsunamis in the Greater Tokyo Area at the Izu-Ogasawara Trench.<ref name="phys1"/> There is a 'trench-trench triple junction' of the oceanic Philippine Sea Plate that underthrusts a continental plate and is being subducted by the Pacific Plate.<ref name="phys1">{{cite web |author=Simon Fraser University |website=Phys.org |title=New source for earthquakes and tsunamis in the Greater Tokyo Region identified |url=https://phys.org/news/2021-09-source-earthquakes-tsunamis-greater-tokyo.html |access-date=September 12, 2021 |url-status=live |archive-url=https://web.archive.org/web/20210904134332/https://phys.org/news/2021-09-source-earthquakes-tsunamis-greater-tokyo.html |archive-date=September 4, 2021}}</ref>

Reclaimed land and human-made islands are particularly susceptible to liquefaction during an earthquake. As a result, there are specific earthquake resistance standards and ground reform work that apply to all construction in these areas. In an area that was possibly reclaimed in the past, old maps and land condition drawings are checked, and drilling is carried out to determine the strength of the ground. However, this can be very costly, so for a private residential block of land, a Swedish weight sounding test is more common.<ref name="reclaimed-land"/>

Japan has become a world leader in research on the causes and prediction of earthquakes.<ref name=loc/> The development of advanced technology has permitted the construction of skyscrapers even in earthquake-prone areas.<ref name=loc/> Extensive civil defense efforts focus on training in protection against earthquakes, in particular against accompanying fire, which represents the greatest danger.<ref name=loc/>

===Volcanic eruptions=== [[File:Sakurajima_20091003.jpg|thumb|upright|Sakurajima eruption on October 3, 2009]] {{see also|List of volcanoes in Japan}} Japan has 111 active volcanoes. That is 10% of all active volcanoes in the world. Japan has stratovolcanoes near the subduction zones of the tectonic plates. During the 20th century, several new volcanoes emerged, including Shōwa-shinzan on Hokkaido and Myōjin-shō off the Bayonnaise Rocks in the Pacific.<ref name="volcanoes-japan">{{cite web |url=http://volcano.und.edu/vwdocs/volc_images/north_asia/japan_tec.html |archive-url=https://web.archive.org/web/20070204064754/http://volcano.und.edu/vwdocs/volc_images/north_asia/japan_tec.html |archive-date=February 4, 2007 |title=Tectonics and Volcanoes of Japan |publisher=Oregon State University |access-date=March 27, 2007}}</ref> In 1991, Japan's Unzen Volcano on Kyushu, about {{convert|40|km|abbr=on}} east of Nagasaki, awakened from its 200-year slumber to produce a new lava dome at its summit. Beginning in June, repeated collapse of this erupting dome generated ash flows that swept down the mountain's slopes at speeds as high as {{convert|200|km/h|abbr=on}}. Unzen erupted in 1792 and killed more than 15,000 people. It is the worst volcanic disaster in the country's recorded history.<ref name="dynearth">{{USGS|title=Plate tectonics and people|last1=Kious|first1=W. Jacquelyne|last2=Tilling|first2=Robert I.|url=https://pubs.usgs.gov/gip/dynamic/tectonics.html}}</ref>

Mount Fuji is a dormant stratovolcano that last erupted on 16 December 1707 till about 1 January 1708.<ref name=GSJ_active>{{cite web |title=Active Volcanoes of Japan |url=https://gbank.gsj.jp/volcano/Quat_Vol/act_map_e.html |publisher=Geological Survey of Japan |work=AIST |access-date=March 7, 2016 |archive-date=March 8, 2016 |archive-url=https://web.archive.org/web/20160308105251/https://gbank.gsj.jp/volcano/Quat_Vol/act_map_e.html |url-status=live }}</ref><ref name=Britannica>{{cite web |url=https://www.britannica.com/EBchecked/topic/221527/Mount-Fuji |title=Mount Fuji |publisher=Encyclopædia Britannica, inc. |date=11 September 2019 |access-date=21 June 2022 |archive-date=29 October 2009 |archive-url=https://web.archive.org/web/20091029041347/http://www.britannica.com/EBchecked/topic/221527/Mount-Fuji |url-status=live }}</ref> The Hōei eruption of Mount Fuji did not have a lava flow, but it did release some {{convert|800|e6m3}} of volcanic ash. It spread over vast areas around the volcano and reached Edo almost {{convert|100|km|-1}} away. Cinders and ash fell like rain in Izu, Kai, Sagami, and Musashi provinces.<ref>{{cite book |language=fr |last1=Titsingh |first1=Isaac |last2=von Klaproth |first2=Julius |author3=Siyun-zai Rin-siyo |date=1834 |url=https://archive.org/details/niponodaitsiran01ringoog |oclc=63259938 |title=Nipon o daï itsi ran; ou, Annales des empereurs du Japon |page=416 |publisher=Paris, Printed for the Oriental Translation Fund; [etc., etc.]}}</ref> In Edo, the volcanic ash was several centimeters thick.<ref>{{cite web |title=18. 噴火災害 |language=ja |website=dil.bosai.go.jp |url=http://dil.bosai.go.jp/library/bousai/funkasaigai/explosion.htm |archive-url=https://web.archive.org/web/20110325062432/http://dil.bosai.go.jp/library/bousai/funkasaigai/explosion.htm |archive-date=March 25, 2011}}</ref> The eruption is rated a 5 on the Volcanic Explosivity Index.<ref name="Fuji — Eruption History">{{cite web |url=http://www.volcano.si.edu/volcano.cfm?vn=283030 |title=Fuji — Eruption History |website=Global Volcanism Program |publisher=Smithsonian Institution |access-date=10 August 2013 |archive-date=11 March 2022 |archive-url=https://web.archive.org/web/20220311110333/https://volcano.si.edu/volcano.cfm?vn=283030 |url-status=live }}</ref>[[File:Aso-4_tephra_90-85ka.svg|thumb|Mount Aso 4 pyroclastic flow and the spread of Aso 4 tephra (90,000 to 85,000 years ago). The pyroclastic flow reached almost the whole area of Kyushu, and volcanic ash was deposited of 15 cm in a wide area from Kyushu to southern Hokkaido.]]

There are three VEI-7 volcanoes in Japan. These are the Aira Caldera, the Kikai Caldera, and the Aso Caldera. These giant calderas are remnants of past eruptions. Mount Aso is the largest active volcano in Japan. 300,000 to 90,000 years ago, there were four eruptions of Mount Aso that emitted huge amounts of volcanic ash that covered all of Kyushu and up to Yamaguchi Prefecture. * The Aira Caldera is 17 kilometers long and 23 kilometers wide, located in south Kyushu. The city of Kagoshima and the Sakurajima volcano are within the Aira Caldera. Sakurajima is the most active volcano in Japan.<ref>{{Cite web |url=https://www.nippon.com/en/features/h00194/ |title=Sakurajima, Japan's Most Active Volcano |date=2018-05-16 |website=nippon.com |publisher=Nippon Communications Foundation |access-date=2018-08-02 |df=mdy-all |archive-date=2018-08-03 |archive-url=https://web.archive.org/web/20180803013956/https://www.nippon.com/en/features/h00194/ |url-status=live }}</ref> * The Aso Caldera stretches 25 kilometers north to south and 18 kilometers east to west in Kumamoto Prefecture, Kyushu. It has erupted four times: 266,000 and 141,000 years ago with 32 DRE km3 (dense-rock equivalent) each; 130,000 years ago with 96 DRE km3; and 90,000 years ago with 384 DRE km3.<ref name="52Aso">[https://www.gsj.jp/data/openfile/no0613/52Aso.pdf 阿蘇カルデラ] 産総研</ref> * The Kikai Caldera is a massive, mostly submerged caldera up to 19 kilometres (12 mi) in diameter in the Ōsumi Islands of Kagoshima Prefecture, Japan. It is the remains of the ancient eruption of a colossal volcano. Kikai Caldera was the source of the Akahoya eruption, one of the largest eruptions during the Holocene (10,000 years ago to present). About 4,300 BC, pyroclastic flows from that eruption reached the coast of southern Kyūshū up to {{convert|100|km|mi|abbr=on}} away, and ash fell as far as Hokkaido. The eruption produced about 150 km3 of tephra,<ref>[http://www.volcano.si.edu/world/volcano.cfm?vnum=0802-06=&volpage=erupt Kikai – Eruptive history] {{Webarchive|url=https://web.archive.org/web/20120820003439/http://www.volcano.si.edu/world/volcano.cfm?vnum=0802-06=&volpage=erupt |date=2012-08-20 }}, Global Volcanism Program. Smithsonian Institution.</ref> giving it a Volcanic Explosivity Index of 7.<ref>Johnston, Eric, "[http://search.japantimes.co.jp/cgi-bin/nn20110301i1.html Latest volcano show: Shinmoe] {{Webarchive|url=https://archive.today/20120715074943/http://search.japantimes.co.jp/cgi-bin/nn20110301i1.html |date=2012-07-15 }}", ''The Japan Times'', 1 March 2011, p. 3.</ref> The Jōmon culture of at least southern Kyushu was destroyed, and it took nearly 1,000 years to recover.<ref name = "KOBEC Caldera Eruption"/>

Surveys by KOBEC (Kobe Ocean-Bottom Exploration Center) confirm that a giant lava dome of 23 cubic kilometers formed after the Kikai Caldera erupted in 4,300 BC. There is a 1% chance of a giant caldera eruption in the Japanese archipelago within the next 100 years. Approximately 40 cubic kilometers of magma would be released in one burst and cause enormous damage.<ref name = "Japan's Kikai Caldera">{{cite web |title=Giant lava dome confirmed in Japan's Kikai Caldera |format=website |url=http://www.kobe-u.ac.jp/research_at_kobe_en/NEWS/news/2018_02_09_01.html |archive-url=https://web.archive.org/web/20180727045127/http://www.kobe-u.ac.jp/research_at_kobe_en/NEWS/news/2018_02_09_01.html |archive-date = July 27, 2018 |publisher=Kobe Ocean Bottom Exploration Center (KOBEC) | access-date = 31 March 2019}}</ref>

According to a 2014 study by KOBEC of Kobe University, in a worst-case scenario, if there is a VEI-7 eruption of the Aso Caldera and if the volcanic ash is carried by westerly winds, then pyroclastic flows would cover the 7 million population near the Aso Caldera within two hours. The pyroclastic flows could reach much of Kyushu. Beyond the pyroclastic area is volcanic ash that falls from the sky. If the volcanic ash continuously flows northward, then the ash fall would make it impossible to live normally in large parts of the main islands of Japan due to the paralysis of traffic and lifelines for a limited period (a few days to 2 weeks) until the eruption subsides. In this scenario, the exception would be eastern and northern Hokkaido (the Ryukyu Islands and southern Nanpo Islands would also be excluded). Professor Yoshiyuki Tatsumi, head of KOBEC, told the ''Mainichi Shimbun'' that "the probability of a gigantic caldera eruption hitting the Japanese archipelago is 1 percent in the next 100 years" with a death toll of many tens of millions of people and wildlife.<ref name = "KOBEC Caldera Eruption">{{cite web |title=巨大カルデラ噴火のメカニズムとリスクを発表 (Announce the mechanism and risk of a huge caldera eruption) |work=国立大学法人神戸大学 (Kobe University) |format=website |url=http://www.kobe-u.ac.jp/NEWS/info/2014_10_22_01.html |archive-url=https://web.archive.org/web/20190330103442/http://www.kobe-u.ac.jp/NEWS/info/2014_10_22_01.html |archive-date = March 30, 2019 |publisher=Kobe University | access-date = 31 March 2019}}</ref> The potential exists for tens of millions of humans and other living beings to die during a VEI-7 volcanic eruption with significant short-term effects on the global climate. Most casualties would occur in Kyushu from the pyroclastic flows. The potential damage from the volcanic ash depends on the wind direction. If, in another scenario, the wind blows in a western or southern direction, then the volcanic ash could affect the East Asian continent or South-East Asia. If the ash flows eastward, then it will spread over the Pacific Ocean. Since the Kikai Caldera is submerged, it is unclear how much damage the hot ash clouds would cause if large quantities of volcanic ash stayed beneath the ocean surface. The underwater ash would be swept away by ocean currents.

Paektu Mountain on the Chinese–North Korean border had a VEI-7 eruption in 946. Paektu Mountain is mainly a threat to the surrounding area in North Korea and Manchuria. The west coast of Hokkaido is about {{convert|971.62|km|abbr=on}} away. However, a temple in Japan reported "white ash falling like snow" on 3 November 946 AD.<ref name="paektu-sd">{{Cite press release |url=https://www.sciencedaily.com/releases/2017/01/170129111657.htm# |title=Fossilized tree and ice cores help date huge volcanic eruption 1,000 years ago to within three months |website=Science Daily.com |access-date=8 February 2017 |archive-url=https://web.archive.org/web/20201112013611/https://www.sciencedaily.com/releases/2017/01/170129111657.htm |archive-date=November 12, 2020}}</ref> So strong winds carried the volcanic ash eastward across the Sea of Japan. An average of {{convert|5|cm|abbr=on}} of ashfall covered about {{convert|1500000|km2|abbr=on}} of the Sea of Japan and northern Japan (Hokkaido and Aomori Prefecture).<ref name=":1">{{Cite journal |title=Volatile emission during the eruption of Baitoushan Volcano (China/North Korea) ca. 969 AD |last=Horn |first=S |date=2000 |journal=Bull Volcanol |doi=10.1007/s004450050004 |volume=61 |issue=8 |pages=537–555 |bibcode=2000BVol...61..537H |s2cid=129624918}}</ref> It took the ash clouds a day or so to reach Hokkaido.<ref name="paektu-sd"/> The total eruption duration was 4 and a half to 14 days (111–333 hours).<ref name="changbaishan">{{Cite book |title=Modern eruption of Changbaishan Tianchi volcano |last=L'iu |first=RX |publisher=China Science Publishing |year=1998}}</ref>

In October 2021, large quantities of pumice pebbles from the submarine volcano Fukutoku-Okanoba damaged fisheries, tourism, the environment, 11 ports in Okinawa, and 19 ports in Kagoshima prefecture.<ref name="pumice"/> Clean-up operations took 2–3 weeks.<ref name="pumice">{{cite web |date=October 30, 2021 |title=Japan ports swamped by pumice spewed from undersea volcano |website=The Guardian |url=https://www.theguardian.com/world/2021/oct/30/japan-ports-swamped-by-pumice-spewed-from-undersea-volcano |archive-url=https://web.archive.org/web/20211030070901/https://www.theguardian.com/world/2021/oct/30/japan-ports-swamped-by-pumice-spewed-from-undersea-volcano |archive-date=October 30, 2021}}</ref>

{| class="wikitable sortable mw-collapsible" |+VEI 7 eruptions happened in the following locations of Japan. !Name !Zone !Location !Event / notes !Years ago before 1950 (Approx.) !Ejecta volume (Approx.) |- valign="top" | '''Kikai Caldera''' | | Japan, Ryukyu Islands | Akahoya eruption 5,300 BC | style="text-align:right;"| 7,300<ref name="Smith2013">{{Cite journal |date=2013 |title=Identification and correlation of visible tephras in the Lake Suigetsu SG06 sedimentary archive, Japan: chronostratigraphic markers for synchronising of east Asian/west Pacific palaeoclimatic records across the last 150 ka |author=Smith|display-authors=etal |journal=Quaternary Science Reviews |volume=67 |pages=121–137 |doi=10.1016/j.quascirev.2013.01.026 |bibcode=2013QSRv...67..121S}}</ref> | style="text-align:right;"| 170 km3 |- valign="top" | '''Aira Caldera''' | | Japan, Kyūshū | Aira-Tanzawa ash | style="text-align:right;"| 30,000<ref name="Smith2013"/> | style="text-align:right;"| 450 km3 |- valign="top" | '''Aso Caldera''' | | Japan, Kyūshū | Aso-4 pyroclastic flow | style="text-align:right;"| 90,000 | style="text-align:right;"| 600 km3 |- valign="top" | '''Mount Aso''' | | Japan, Kyūshū | Four large eruptions between 300,000 and 90,000 years ago. | style="text-align:right;"| 300,000 | style="text-align:right;"| 600 km3 |}

Improving technology and methods to predict volcano and giant caldera eruptions would help to prepare and evacuate people earlier. Technology is needed to accurately capture the state of the magma chamber, which spreads thinly with a thickness of less than several kilometers around the middle of the crust. The underground area of Kyushu must be monitored because it is a dangerous area with the potential for a caldera eruption. The most protective measure is to stop the hot ash clouds from spreading and devastating areas near the eruption so that people don't need to evacuate. There are currently no protective measures to minimize the spread of millions of tons of deadly hot ash during a VEI-7 eruption.

In 2018, NASA published a theoretical plan to prevent a volcanic eruption by pumping large quantities of cold water down a borehole into the hydrothermal system of a supervolcano. The water would cool the huge body of magma in the chambers below the volcano so that the liquid magma would become semi-solid. Thus, enough heat could be extracted to prevent an eruption. The heat could be used by a geothermal plant to generate geothermal energy and electricity.<ref name=NASA-supervolcano>{{cite news |url=https://www.businessinsider.com/nasa-is-looking-at-how-to-contain-a-volcano-that-may-wipe-out-humanity-2018-10 |title=NASA is trying to figure out how to contain a supervolcano that could destroy humanity |work=Business Insider |date=October 6, 2018|access-date=January 31, 2019 |url-status=live |archive-url=https://web.archive.org/web/20190111060313/https://www.businessinsider.com/nasa-is-looking-at-how-to-contain-a-volcano-that-may-wipe-out-humanity-2018-10/ |archive-date=2019-01-11}}</ref>

===Typhoons=== {{Main|Typhoons in Japan}} Since recording started in 1951, an average of 2.6 typhoons reached the main islands of Kyushu, Shikoku, Honshu, and Hokkaido per year. Approximately 10.3 typhoons approach within the 300-kilometer range near the coast of Japan. Okinawa is, due to its geographic location, most vulnerable to typhoons, with an average of 7 storms per year. The most destructive was the Isewan Typhoon, with 5,000 casualties in the Tokai region in September 1959. In October 2004, Typhoon Tokage caused heavy rain in Kyushu and central Japan, resulting in 98 casualties. Until the 1960s, the death toll was hundreds of people per typhoon. Since the 1960s, improvements in construction, flood prevention, high tide detection, and early warnings have substantially reduced the death toll, which rarely exceeds a dozen people per typhoon. Japan also has special search and rescue units to save people in distress.

Heavy snowfall during the winter in the snow country regions causes landslides, flooding, and avalanches.

==Environmental issues== {{main|Environmental issues in Japan}}In the 2006 environment annual report,<ref>[http://www.env.go.jp/en/wpaper/2006/02.pdf Annual Report on the Environment in Japan 2006] {{Webarchive|url=https://web.archive.org/web/20230813205236/https://www.env.go.jp/en/wpaper/2006/02.pdf |date=2023-08-13 }}, Ministry of the Environment</ref> the Ministry of Environment reported that the current major issues are: global warming and preservation of the ozone layer; conservation of the atmospheric environment, water, and soil; waste management and recycling; measures for chemical substances; conservation of the natural environment; and participation in international cooperation.

==See also== {{Portal|Japan|Geography}} * List of peninsulas of Japan * Japanese addressing system

==References== {{reflist|colwidth=30em}} * [https://www.cia.gov/the-world-factbook/countries/japan/ Japan] {{Webarchive|url=https://web.archive.org/web/20210105105736/https://www.cia.gov/the-world-factbook/countries/japan/ |date=2021-01-05 }}. ''The World Factbook''. Central Intelligence Agency..

==External links== {{commons category|Geography of Japan}} * [http://www.wdl.org/en/item/75 "Colton's Japan: Nippon, Kiusiu, Sikok, Yesso and the Japanese Kuriles"] {{Webarchive|url=https://web.archive.org/web/20170504085115/https://www.wdl.org/en/item/75/ |date=2017-05-04 }} a map from 1855 * [http://maps.gsi.go.jp/?ll=35.799994,139.680176&z=5&base=english&ls=lake2%7Crelief&disp=11&vs=c1j0l0u0 Terrain of Japan] {{Webarchive|url=https://web.archive.org/web/20170512072905/http://maps.gsi.go.jp/?ll=35.799994,139.680176&z=5&base=english&ls=lake2%7Crelief&disp=11&vs=c1j0l0u0 |date=2017-05-12 }} – GJI Maps (Geospatial Information Authority of Japan)

Category:Geography of Japan Category:Lists of subdivisions of Japan

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