ABSTRACT
Humankind has an often uneasy relationship with the geosphere on which it dwells. Frequently, there is a need to modify the geosphere to construct dwellings and other structures, to build roads and railroads, to impound water, or for a number of other purposes. Humans are often unpleasantly surprised by the results of their efforts as destructive landslides form on sloping ground, dams collapse releasing destructive fl oods, and other unforeseen consequences result. Some natural geospheric processes are quite destructive of property and even human life. The two most dangerous of these are earthquakes and volcanoes. These are internal phenomena that result from changes deep underground. Surface processes, including landslides and ground subsidence, can be very destructive to property. Though usually not threatening to human life, surface processes can cause fatalities. Perhaps the most dangerous such processes are mudslides following extremely high rainfalls that sometimes bury whole villages entombing their residents. Cases have occurred in which vast amounts of earthen material have slid into reservoirs, causing them to overfl ow violently drowning many people downstream.
