devastation of local regions. Volcanic eruptions and associated phenomena have killed tens of thousands of people in the 20th century, including the massive mudslides at Nevada del Ruiz, Colombia, that killed 23,000 in 1985. some of the larger volcanic eruptions cover huge parts of the globe with volcanic ash and are capable of changing the global climate. Plate tectonics is also responsible for uplifting the world's mountain belts, which are associated with their own sets of hazards, particularly landslides and other mass wasting phenomena.
some geologic hazards are associated with steep slopes and the effects of gravity moving material down these slopes to inhabited areas. Landslides and the slow downhill movement of earth material occasionally kill thousands in large disasters, such as when parts of a mountain collapsed in 1970 in the Peruvian Andes and buried a village several tens of miles away, killing 60,000 people. Downhill movements are typically more localized and destroy individual homes, neighborhoods, roads, or bridges. some downslope processes are slow and involve the inch-by-inch (cm by cm) creeping of soil and other earth material downhill, taking everything with it during its slide. Creep is one of the costliest of natural
Was this article helpful?