Friday 14 January 2011
Instrument: HRSC: High-Resolution Stereo Camera
Phoenicis Lacus has an area of 8100 sq km (59.5 x 136 km), which corresponds to the size of Corsica. Only a small portion of it appears in this image, which was obtained on 31 July 2010 using the High-Resolution Stereo Camera (HRSC) on ESA’s Mars Express spacecraft. Phoenicis Lacus was formed by the uplift of the Tharsis plateau. The continual episodes of strong volcanic activity in Tharsis not only lifted the plateau, but also deformed Phoenicis Lacus, creating blocks and multiple fault lines at different orientations. Extension has taken place here, resulting in this characteristic ‘horst-and-graben’ (cliffs and valleys) landscape. A prominent collapse feature in the region is visible in this image. It shows as a long pit and sinks to a depth of about 3 km below the surrounding plains. Its walls give a glimpse of extensive basalt layers and a small field of sand dunes covers the floor.