A system of large, arcuate normal faults lie radial to the volcano's center. The normal faults have large offsets and transect the volcano into at least four sectors. The north and south sectors have smooth, convex upward profiles. The western and eastern sectors of the volcano consist of huge, down-dropped blocks. A large debris avalanche deposit (DAD) is present at the northwestern edge of the western block. The DAD appears to be made up of coherent slabs of flank material originating from the down-dropped western flank. Some researchers have compared the deformation on the flanks of Tharsis Tholus to sector collapse observed at Mauna Loa in Hawaii and other terrestrial volcanoes. Sector collapse is a sudden, catastrophic detachment of a volcano's flank caused by lateral spreading of the volcano. Another suggested terrestrial analog for Tharsis Tholus is the Maderas Volcano in Nicaragua.