Landslides often have devastating effects on humans. The wall of mud wipes out buildings, covers roads and changes the landscape. The economic cost of landslides in the United States ranges from $1 billion to $2 billion annually. NBC News reports a death toll of 41 individuals with two missing from the March 22, 2014, landslide in Oso, Washington.Continue Reading
Many landslides are the aftereffects of volcanoes or earthquakes. The damage they cause is often more significant than the damage caused by the triggering event.
Both natural and human forces increase the likelihood of a landslide. Activity at the base of the incline, such as the cutting action of a river or excavation by humans, removes some of the supporting material, giving gravity a greater advantage at moving the sediment from the higher layer.
According to HowStuffWorks.com, geologists classify landslides as "mass movement," a term describing any kind of "gravity induced movement of sediment down a slope." While some mass movements occur slowly over several years, landslides often occur in a matter of minutes. Mass movements are sometimes small, as when a deer kicks a few rocks down an incline. Others are large, such as the 1980 landslide due to Mount St. Helens' eruption. From a technical point of view, a landslide is a specific type of mass movement in which sediment loosens from its underlying bedrock along a distinct line of weakness, separates and moves down a slope in a rapid fashion.Learn more about Earth Science
Mass movement, or mass wasting, has significant effects on humans, including loss of property, severe injury and death. This has become a larger problem as the human population grows and people have spread over more previously uninhabited land. The effects are also greater in underdeveloped countries that lack zoning laws, information and disaster preparedness.Full Answer >
Excavations and agricultural activities are the two primary ways humans influence the geosphere. One example from the 20th century was the Dust Bowl, in which farming practices in the Midwest led to the erosion of topsoil, rendering the Great Plains largely unable to support crops.Full Answer >
As opposed to man-made structures, natural structures are those forms that stand on their own and take a specific configuration but are not made by humans, including things like beehives, rock arches, canyons, eggshells, bird's nests, coral reefs and naturally formed caves. One way to understand natural structures is to look at the difference between natural structural phenomena such as mountain ranges compared to man-made structures such as houses and highways. Natural structures are created from the Earth's natural forces or through the efforts of animals.Full Answer >
Olduvai Gorge is important due to the famous discoveries by Mary and Louis Leakey of early humans from about 2 million years ago in the area. This led to a documentation of the evolutionary history of vertebrate fauna, the ancestors that used stone tools and the environment.Full Answer >