The shield volcano Pavonis Mons, perspective colour view. The surface structures seen in the view lie on the south-west flank of the volcano. The dramatic features visible in the colour image are located on the south western flank of the volcano. Researchers believe these are lava tubes, channels originally formed by hot, flowing lava that forms a crust as the surface cools. Lava continues to flow beneath this hardened surface, but when the lava production ends and the tunnels empty, the surface collapses, forming elongated depressions.
Image: Copyright ESA/DLR/FU Berlin (G. Neukum).