Collapsed Subsurface Channel
Jet Propulsion Laboratory https://www.jpl.nasa.gov/ April 16, 2004
16 April 2004
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows evidence of a collapsed lava tube (or other form of subterranean channel) on the plains northwest of the Elysium volcanoes. Lava or another fluid (e.g., water) was transported through a subsurface channel; later, the roof collapsed to form a series of pits and troughs, revealing the channel's location. This landform is located near 32.7°N, 219.5°W. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.