# Ice calving > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Ice_calving > Markdown URL: https://mediated.wiki/source/Ice_calving.md > Source: https://en.wikipedia.org/wiki/Ice_calving > Source revision: 1316519079 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Breaking of ice chunks from the edge of a glacier}} {{Use dmy dates|date=January 2025}}{{Use British English|date=January 2025}} [[File:SantaCruz-Spegazzini-CaidaAnimation.gif|thumb|right|A mass of ice calves from the [Perito Moreno glacier](/source/Perito_Moreno_glacier) in [Lago Argentino](/source/Lago_Argentino)]] '''Ice calving''', also known as '''glacier calving''' or '''iceberg calving''', is the breaking of ice chunks from the edge of a glacier.Essentials of Geology, 3rd edition, Stephen Marshak It is a form of [ice ablation](/source/Ablation_zone) or [ice disruption](/source/Ice_shelf). It is the sudden release and breaking away of a mass of [ice](/source/ice) from a [glacier](/source/glacier), [iceberg](/source/iceberg), [ice front](/source/ice_front), [ice shelf](/source/ice_shelf), or [crevasse](/source/crevasse). The ice that breaks away can be classified as an iceberg, but may also be a growler, bergy bit, or a crevasse wall breakaway.[http://ebeltz.net/glacier/glacglos.html Glossary of Glacier Terms], Ellin Beltz, 2006. Retrieved July 2009. Calving of glaciers is often accompanied by a loud cracking or booming sound[https://www.nps.gov/glba/learn/nature/glaciers.htm Glacier Bay], National Park Service. Retrieved July 2009. before blocks of ice up to {{convert|60|m|ft}} high break loose and crash into the water. The entry of the ice into the water causes large, and often hazardous waves.[http://nsidc.org/gallery/staff/glacier_calving_photos.html Glacier Calving photos] {{Webarchive|url=https://web.archive.org/web/20100125073056/http://nsidc.org/gallery/staff/glacier_calving_photos.html |date=2010-01-25 }}. Retrieved July 2009. The waves formed in locations like [Johns Hopkins Glacier](/source/Johns_Hopkins_Glacier) can be so large that boats cannot approach closer than {{convert|3|km|nmi|frac=2|abbr=off|spell=in}}. These events have become major tourist attractions in locations such as [Alaska](/source/Alaska). Many glaciers terminate at oceans or freshwater lakes which results naturally[http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf ARCTIC, Vol. 39, No. 1 (March 1986) P. 15-19, ''Ice Island Calvings and Ice Shelf Changes, Milne Ice Shelf and Ayles Ice Shelf, Ellesmere Island, N.W.T.''] {{Webarchive|url=https://web.archive.org/web/20190928113808/http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf |date=2019-09-28 }}, Martin O. Jeffries, 1985, University of Calgary. Retrieved 18 July 2009. with the calving of large numbers of icebergs. Calving of [Greenland](/source/Greenland)'s glaciers produce 12,000 to 15,000 icebergs each year alone.[https://archive.today/20070806200947/http://www.oxfam.org.zw/coolplanet/ontheline/explore/nature/oceans/prtoceans.htm Oceans], Oxfam. Retrieved June 2009. Calving of ice shelves is often preceded by a rift.{{cite web|author=Promotions/Public Relations |url=http://www.aad.gov.au/default.asp?casid=11975 |title=The loose tooth: rifting and calving of the Amery Ice Shelf - Australian Antarctic Division |publisher=Aad.gov.au |date=2006-12-08 |access-date=2010-07-30 |url-status=dead |archive-url=https://web.archive.org/web/20091002042344/http://www.aad.gov.au/default.asp?casid=11975 |archive-date=October 2, 2009 }} An ice shelf in steady state calves at roughly the same rate as the influx of new ice,{{cite journal |last1=Rignot |first1=E. |last2=Jacobs |first2=S. |last3=Mouginot |first3=J. |last4=Scheuchl |first4=B. |title=Ice-Shelf Melting Around Antarctica |journal=Science |date=19 July 2013 |volume=341 |issue=6143 |pages=266–270 |doi=10.1126/science.1235798|pmid=23765278 |s2cid=206548095 |url=http://www.escholarship.org/uc/item/0jm230gv |doi-access=free |bibcode=2013Sci...341..266R }}{{cite journal |last1=Depoorter |first1=M. A. |last2=Bamber |first2=J. L. |last3=Griggs |first3=J. A. |last4=Lenaerts |first4=J. T. M. |last5=Ligtenberg |first5=S. R. M. |last6=van den Broeke |first6=M. R. |last7=Moholdt |first7=G. |title=Calving fluxes and basal melt rates of Antarctic ice shelves |journal=Nature |date=3 October 2013 |volume=502 |issue=7469 |pages=89–92 |doi=10.1038/nature12567|pmid=24037377 |bibcode=2013Natur.502...89D |s2cid=4462940 |url=https://epic.awi.de/id/eprint/33781/1/Antarctica_masks.zip }} and calving events may occur on sub-annual to decadal timescales to maintain an overall average mean position of the ice shelf front. When calving rates exceed the influx of new ice, ice front retreat occurs, and ice shelves may grow smaller and weaker.{{cite journal |last1=Greene |first1=Chad A. |last2=Gardner |first2=Alex S. |last3=Schlegel |first3=Nicole-Jeanne |last4=Fraser |first4=Alexander D. |title=Antarctic calving loss rivals ice-shelf thinning |journal=Nature |date=10 August 2022 |volume=609 |issue=7929 |pages=948–953 |doi=10.1038/s41586-022-05037-w|pmid=35948639 |bibcode=2022Natur.609..948G |s2cid=251495070 }} ==Causes== thumb|Video of iceberg calving in Greenland, 2007 thumb|right|A calving glacier and the resulting ice field [[File:Glacier Bay - Johns Hopkins glacier calving.jpg|thumb|upright=0.8|[Glacier Bay](/source/Glacier_Bay), glacier calving]] It is useful to classify causes of calving into first, second, and third order processes.{{cite journal | last1 = Benn | first1 = D. | last2 = Warren | first2 = C. | last3 = Mottram | first3 = R. | year = 2007 | title = Calving processes and the dynamics of calving glaciers | url = http://stuff.mit.edu/~heimbach/papers_glaciology/earthscirev_benn_etal_2007_calving.pdf | journal = Earth-Science Reviews | volume = 82 | issue = 3–4| pages = 143–179 | doi=10.1016/j.earscirev.2007.02.002| bibcode = 2007ESRv...82..143B }} First order processes are responsible for the overall rate of calving at the glacier scale. The first order cause of calving is longitudinal stretching, which controls the formation of [crevasse](/source/crevasse)s. When crevasses penetrate the full thickness of the ice, calving will occur.{{cite journal | last1 = Nick | first1 = F. | last2 = Van der Veen | first2 = C. | last3 = Vieli | first3 = A. | last4 = Benn | first4 = D. | year = 2010 | title = A physically based calving model applied to marine outlet glaciers and implications for the glacier dynamics | journal = Journal of Glaciology | volume = 56 | issue = 199 | page = 781 | doi = 10.3189/002214310794457344 | bibcode = 2010JGlac..56..781N | doi-access = free | hdl = 1808/17292 | hdl-access = free }} Longitudinal stretching is controlled by [friction](/source/friction) at the base and edges of the glacier, glacier geometry and [water pressure](/source/Fluid_pressure) at the bed. These factors, therefore, exert the primary control on calving rate. Second and third order calving processes can be considered to be superimposed on the first order process above, and control the occurrence of individual calving events, rather than the overall rate. Melting at the waterline is an important second order calving process as it undercuts the [subaerial](/source/subaerial) ice, leading to collapse. Other second order processes include tidal and seismic events, [buoyant](/source/buoyancy) forces and melt water wedging. When calving occurs due to waterline melting, only the subaerial part of the glacier will calve, leaving a submerged 'foot'. Thus, a third order process is defined, whereby upward buoyant forces cause this ice foot to break off and emerge at the surface. This process is extremely dangerous, as it has been known to occur, without warning, up to {{convert|300|m|ft|abbr=on}} from the glacier terminus.{{cite web|last1=Kohler|first1=Jack|title=How close should boats come to the fronts of Svalbard's calving glaciers?|url=http://www.aeco.no/documents/CalvingglaciersNPreport2008.pdf|publisher=Norwegian Polar Institute|access-date=18 January 2018|archive-url=https://web.archive.org/web/20100928022706/http://www.aeco.no/documents/CalvingglaciersNPreport2008.pdf|archive-date=2010-09-28|date=September 28, 2010}} ==Calving law== Though many factors that contribute to calving have been identified, a reliable predictive [mathematical formula](/source/mathematical_formula) is still under development. Data is currently being assembled from ice shelves in [Antarctica](/source/Antarctica) and Greenland to help establish a 'calving law'. Variables used in models include properties of the ice such as thickness, density, [temperature](/source/temperature), [https://doi.org/10.3189/S0022143000017895 c-axis fabric], and impurity loading. A property known as 'ice front normal spreading stress' may be of key importance, despite it not normally being measured. {{Citation needed|date=February 2010}} There are currently several concepts upon which to base a predictive law. One theory states that the calving rate is primarily a function of the ratio of [tensile stress](/source/tensile_stress) to vertical compressive stress, i.e., the calving rate is a function of the ratio of the largest to smallest principle stress.{{cite journal|title=Modeling Iceberg Calving From Ice Shelves Using a Stress Based Calving Law: The |publisher=Adsabs.harvard.edu |bibcode=2008AGUFM.C41D..03B|last1=Bassis |first1=J. N. |last2=MacAyeal |first2=D. R. |last3=Alley |first3=R. |journal=AGU Fall Meeting Abstracts |year=2008 |volume=2008 }} Another theory, based on preliminary research, shows that the calving rate increases as a power of the spreading rate near the calving front.{{Citation needed|date=February 2010}} ==Major calving events== ===Filchner-Ronne Ice Shelf=== In October, 1988, the A-38 iceberg broke away from the Filchner-Ronne Ice Shelf. It was about 150 km x 50 km. A second calving occurred in May 2000 and created an iceberg 167 km x 32 km. ===Amery Ice Shelf=== {{Further|Amery Ice Shelf#Calving}} A major calving event occurred in 1962 to 1963, resulting in an iceberg approximately 10,000 sq km in size.{{cite journal| last=Fricker| first=Helen| url=https://www.cambridge.org/core/journals/annals-of-glaciology/article/iceberg-calving-from-the-amery-ice-shelf-east-antarctica/0602BA4781415E4345DC791C636A0F33| title="Iceberg calving from the Amery Ice Shelf, East Antarctica"| journal=Annals of Glaciology|publisher= Cambridge university press| date=September 14, 2017| volume=34| pages=241–246| doi=10.3189/172756402781817581}} In the 1990's scientists identified an exceptionally large rift forming a section at the front of the shelf. Expecting a calving event was imminent, the section was informally named the 'loose tooth". After over 2 decades of anticipation and study, the "tooth" finally calved on Sept. 26, 2019, forming a 1,636 sq km (632 sq mi), 315 billion tonne iceberg known as D-28 {{cite web|last= Pappas|first= Stephanie |url=https://www.livescience.com/giant-loose-tooth-iceberg-calves-antarctica.html# |title='Loose Tooth' Iceberg Calves Off East Antarctica in Surprising Spot |publisher=LiveScience.com|date=October 1, 2019}} ===Ward Hunt Ice Shelf=== {{Further|Ward Hunt Ice Shelf}} The largest observed calving of an ice island happened at Ward Hunt Ice Shelf. Sometime between August 1961 and April 1962 almost {{convert|600|km2|abbr=on}} of ice broke away.{{Cite web |url=http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf |title=ARCTIC, Vol. 39, No. 1 (March 1986) P. 15-19, ''Ice Island Calvings and Ice Shelf Changes, Milne Ice Shelf and Ayles Ice Shelf, Ellesmere Island, N.W.T.'' |access-date=2009-07-10 |archive-date=2019-09-28 |archive-url=https://web.archive.org/web/20190928113808/http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf |url-status=dead }} ===Ayles Ice Shelf=== {{Further|Ayles Ice Shelf}} In 2005, nearly the entire shelf calved from the northern edge of [Ellesmere Island](/source/Ellesmere_Island). Since 1900, about 90% of Ellesmere Island's ice shelves have calved and floated away. This event was the biggest of its kind for at least the past 25 years. A total of {{convert|87.1|km2|sqmi|frac=32|abbr=on}} of ice was lost in this event. The largest piece was {{convert|66.4|km2|sqmi|frac=32|abbr=on}} in area, which is slightly larger than the City of [Manhattan](/source/Manhattan).{{cite web|url=http://www.geomatics.uottawa.ca/copland/ |title=Ayles Ice Shelf - Dr. Luke Copland |publisher=Geomatics.uottawa.ca |access-date=27 January 2017 |archive-date=9 February 2007 |archive-url=https://web.archive.org/web/20070209181133/http://www.geomatics.uottawa.ca/copland/}} [[File:Jakobshavn retreat-1851-2006.jpg|thumb|upright=1.45|[Landsat](/source/Landsat_program) image of [Jacobshavn Isbræ](/source/Jacobshavn_Glacier). The lines show the position of the calving front of the Jakobshavn Isbræ since 1851. The date of this image is 2001, and the calving front of the glacier can be seen at the 2001 line. The area stretching from the calving front to the sea (towards the bottom left corner) is the [Ilulissat](/source/Ilulissat) icefjord. Courtesy of [NASA](/source/NASA) Space Observatory.]] ===Larsen Ice Shelf=== {{Further|Larsen Ice Shelf}} This large ice shelf, located in the [Weddell Sea](/source/Weddell_Sea), extending along the east coast of [Antarctic Peninsula](/source/Antarctic_Peninsula), consists of three segments, two of which have calved. In January 1995, the Larsen A Ice Shelf containing {{convert|3250|km2|abbr=on}} of ice {{convert|200|m|abbr=on}} thick calved and disintegrated. Then the Larsen B Ice Shelf calved and disintegrated in February 2002. ===Jacobshavn Isbræ Glacier=== Also known as the Ilulissat Glacier or Sermeq Kujalleq in western Greenland, in an ongoing event, 35 billion tonnes of icebergs calve off and pass out of the [fjord](/source/fjord) every year. Photographer [James Balog](/source/James_Balog) and his team were examining this glacier in 2008 when their cameras caught a piece of glacier the size of [Lower Manhattan](/source/Lower_Manhattan) fall into the ocean.{{Cite web|url=http://earthsky.org/earth/video-largest-glacier-calving-ever-caught-on-film|title=Video: Largest glacier calving ever caught on film {{!}} EarthSky.org|website=earthsky.org|date=5 February 2013 |language=en-US|access-date=2017-02-20}} The calving event lasted for 75 minutes, during which time the glacier retreated a full mile across a calving face three miles (five kilometers) wide. Adam LeWinter and Jeff Orlowski captured this footage, which is featured in the film ''[Chasing Ice](/source/Chasing_Ice)''. ==Glacier surfing== First conceived in 1995 by Ryan Casey while filming for [IMAX](/source/IMAX), this sport involves a [surfer](/source/surfing) being towed into range by a [jet ski](/source/jet_ski) and waiting for a mass of ice to calve from a glacier.{{cite web|last1=McNamara|first1=Garrett|title=Garrett McNamara Extreme Waterman|url=http://garrettmcnamara.com/}} Surfers can wait for several hours in the icy water for an event. When a glacier calves, the mass of ice can produce {{convert|8|m|abbr=}} waves. Rides of {{convert|300|m|abbr=}} lasting for one minute can be achieved.{{cite web|title=Glacier Surfing|url=http://coolthingsinrandomplaces.com/glacier-surfing/|archive-url=https://web.archive.org/web/20090201141943/http://coolthingsinrandomplaces.com/glacier-surfing|archive-date=February 1, 2009|url-status=usurped|date=June 30, 2008}} ==See also== * [Ablation](/source/Ablation) * [Ice sheet dynamics](/source/Ice_sheet_dynamics) * [Serac](/source/Serac) ==References== {{Reflist|2}} ==Further reading== * Holdsworth, G. 1971. Calving From Ward Hunt Ice Shelf, 1961–1962., Canadian Journal of Earth Sciences 8:299-305. * Jeffries, M. 1982. Ward Hunt Ice Shelf, Spring 1982. Arctic 35542–544. * Jeffries, M.O., And Serson, H. 1983. Recent Changes At The Front Of Ward Nwt. Arctic 36:289-290. Hunt Ice Shelf, Ellesmere Island, Koenig, L.S., Greenaway, K.R., Dunbar, M., And Haitersley * Smith, G. 1952. Arctic Ice Islands. Arctic 5:67-103. * Lyons, J.B., And Ragle, R.H. 1962. Thermal History And Growth Of The Ward Hunt Ice Shelf. International Union Of Geodesy And Geophysics International Association Of Hydrological Sciences, Colloque D’obergurgl, 10–18 September 1962. 88–97. * Rectic And Maykut, G.A., And Untersteiner, N. 1971. Some Results From A Time Of Geophysical Research Dependent Thermodynamic Model Of Sea Ice. Journal 761550–1575. ==External links== {{Commons category}} *[https://web.archive.org/web/20090923231126/http://geosci.uchicago.edu/research/glaciology_files/iceberg_calving_research.shtml University of Chicago article] *[https://www.youtube.com/watch?v=hC3VTgIPoGU "Chasing Ice" captures largest glacier calving ever filmed] {{Ice |expanded}} {{glaciers}} Category:Glaciers Category:Glaciology Category:Articles containing video clips Category:Water ice --- Adapted from the Wikipedia article [Ice calving](https://en.wikipedia.org/wiki/Ice_calving) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Ice_calving?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.