{{Short description|Vallis on Mars}} {{Infobox feature on celestial object |name = Hrad Vallis |image = [[Image:Hrad Vallis in Cebrenia.jpg|200px]] |caption = Hrad Vallis may have been formed when the large [[Elysium Mons]] volcanic complex melted ground ice, as seen by THEMIS. |coordinates = {{coord|38.7|N|224.7|W|globe:mars_type:landmark|display=inline,title}} }}

'''Hrad Vallis''' is an ancient [[outflow channel]] in the [[Cebrenia quadrangle]] of [[Mars]], located at 38.7° north latitude and 224.7° west longitude. It is 825&nbsp;km in length and was named for the word for "Mars" in [[Armenian language|Armenian]].<ref name = "USGS_Hrad_Vallis">{{cite web | title = Hrad Vallis | work = planetarynames.wr.usgs.gov | publisher = [[USGS Astrogeology Science Center]] | url = https://planetarynames.wr.usgs.gov/Feature/2565 | access-date = 2014-07-11}}</ref>

== Volcano ice interactions == Large amounts of water ice are believed to be present under the surface of Mars. Some channels lie near volcanic areas. When hot subsurface molten rock comes close to this ice, large amounts of liquid water and mud may be formed. Hrad Vallis in the Cebrenia quadrangle is close to [[Elysium Mons]], a large [[volcano]], and may have supplied water to create the channel.<ref>{{cite web |url=http://themis.asu.edu/zoom-20020715a.html |title=THEMIS: Image Detail |access-date=2009-02-15 |url-status=dead |archive-url=https://web.archive.org/web/20041016205124/http://themis.asu.edu/zoom-20020715a.html |archive-date=2004-10-16 }}</ref>

<gallery class="center" widths="190px" heights="180px" > Image:Hrad Vallis.JPG|Streamlined islands in Hrad Vallis, as seen by [[HiRISE]]. </gallery>

== References == {{Commons category|Hrad Vallis}} {{Reflist}}

==See also==

* [[Geography of Mars]] * [[Geology of Mars]] * [[HiRISE]] * [[Lakes on Mars]] * [[Outflow channels]] * [[Vallis (planetary geology)]] * [[Water on Mars]]

{{Geography of Mars}}

[[Category:Cebrenia quadrangle]] [[Category:Valleys and canyons on Mars]]

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