Hrad Vallis

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 km in length and was named for the word for "Mars" in Armenian.^[1]

Hrad Vallis

Hrad Vallis may have been formed when the large Elysium Mons volcanic complex melted ground ice, as seen by THEMIS.
Coordinates	38.7°N 224.7°W / 38.7; -224.7

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.^[2]

• 
  Streamlined islands in Hrad Vallis, as seen by HiRISE.

References

1. "Hrad Vallis". Gazetteer of Planetary Nomenclature. USGS Astrogeology Science Center. Retrieved 2014-07-11. {{cite web}}: External link in |work= (help)
2. "THEMIS: Image Detail". Archived from the original on 2004-10-16. Retrieved 2009-02-15.

See also

• Geography of Mars
• Geology of Mars
• HiRISE
• Lakes on Mars
• Outflow channels
• Vallis (planetary geology)
• Water on Mars