Cochise College Student Papers in Geology
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Roger Weller, geology instructor
wellerr@cochise.edu
Landslides
Tracy Cottrell
Physical Geology
Fall 2005
Mass Wasting, Also Known As…
LANDSLIDES
Introduction
Landslides cost billions of dollars and a large number of deaths every year. Many homes are built in these high-risk areas and is unknown to the homeowner. There are many telltale signs of a potential landslide area. Most people are unaware of the severity of landslides. They can take the lives of humans and animals. A lot of work is currently going on to study the causes of landslides and possible prevention of them.
What
are they?
Landslides occur when the earth falls off of a slope. They can be a really slow long process or can take a matter of seconds to cause their damage. Landslides will take everything in their way... anything from people to homes. Landslides can contain rocks, trees, dirt, mud or any combination. Landslides can happen anywhere and are caused by many different factors.
Nature and humans can cause landslides. They can be triggered from anything from heavy rain to a car door shutting. Nature starts the landslides by heavy rain, wind, earthquakes, streams and by falling trees. Humans can cause landslides by walking to close to the edge of a slope.
Construction
is one of the greatest causes of landslides.
With so many people in the US, the need for homes is rapidly increasing.
Good land to build homes on is getting scarce and people are building
anywhere they can. California has
the greatest amount of high-risk homes. There
is such a need for the land that builders are resorting to building on
mountainsides. When part of a
mountain or hill is dug away it creates a steeper slope.
The increased slope now has more gravitational force pulling it.
This causes landslides and can be triggered by a butterfly landing on the
ground. After they cut the slope there is tons of unneeded dirt.
They then put this dirt on top of the mountain because of convenience.
Landslide facts
Cost up to $2 billion dollars a year in damages.
Can take 50 lives a year in the US and thousand around the world.
There are groups of scientists that only work on studies of landslides.
Usually occur with a slope greater than 15%.
Intro
How to identify high-risk areas...
What to do when landslide hits...