Landslide, mudslide, debris flowit doesn't matter what you call it, the outcome is the same: normally stable and stationary soil gets a bad case of wanderlust. In most cases, slides are triggered when too much water saturates a steep slope or when an earthquake shakes the ground loose. This can occur almost anywhere, but Central Americawith its precipitous hills, frequent heavy rainstorms and unstable volcanic soilis probably the number one hotspot. Ed Harp, a landslide geologist with the U.S.