Collapsing Cliff at Telegonus Mensa (MULTISPECTRUM; credits: Lunexit)

Caption NASA:"This mosaic, showing an area called Telegonus Mensa, on Jupiter's moon Io and obtained by using frames taken by the NASA's Galileo Spacecraft on Oct. 16, 2001, reveal a complex interplay of geologic processes.
Four small, HR frames (9,6 mt, or 32 feet, per picture element) have been set into the larger context mosaic, which has a resolution of 42 mt (140 feet) per picture element. The illumination is from the upper right and North is to the top of the mosaic. A fracture runs North-West from the lower right corner of the mosaic into the amphitheater in the center of the frame. A HR image along this fracture reveals that lava has erupted from it.

The amphitheater itself is the site of extensive erosion, as the cliff has slumped South-Eastward under the influence of Io's gravity. HR frames directly south of the amphitheater show another slumping cliff in detail. Flat tops of massive slump blocks — up to 6 Km (3,7 miles) long and 0,5 Km (0,3 miles) across — are illuminated by the the Sun and cast shadows down the face of the cliff.
Based on these shadows, Galileo scientists estimate that the cliff is 1 to 2 Km high.

Just to the left of center a series of landslides can be seen, the longest of which extends for about 4 Km (such as approx. 2,5 miles)".