Landslide Images What is a landslide The downward

Landslide Images

What is a landslide? The downward sliding of a relatively dry mass of earth and rock

What is a mudslide? The downward sliding of soft wet earth and debris, made fluid by rain or melted snow

Types of Landslides • Major types of landslide movements • Landslides occur at different speeds — very slow to very quick • All landslides are the result of gravity, friction and their materials • Both natural and human-made factors contribute to landslides Source: U. S. Geological Survey, http: //pubs. usgs. gov/fs/2004/3072/pdf/fs 20043072. pdf

Wow! Landslides & mudslides can move: • Soil • Gravel • Rocks • Plants • Trees • Houses • Cars • Roads • …and you Source: U. S. Geological Survey, http: //pr. water. usgs. gov/public/venezuela

La Conchita, CA • A typical type of landslide • Landslide and earthflow at a southern California coastal area • People were evacuated • The houses nearest the slide were completely destroyed • Spring 1995 Source: R. L. Schuster, U. S. Geological Survey, http: //pubs. usgs. gov/of/2001/ofr-01 -0276/

La Conchita, California • Debris flow that came from a large landslide above the town • What happened to the road and houses? • March 2005 Source: U. S. Geological Survey, http: //landslides. usgs. gov/recent/socal _reconn/photo 2. php

Laguna Beach, California • A large landslide occurred in the Bluebird Canyon area, near Laguna Beach • What happened to the road and houses? • 2005 Source: Jim Bowers, U. S. Geological Survey, http: //landslides. usgs. gov/recent/.

Carabelleda, Venezuela • An aerial view shows newly opened channels of debris flow (in foreground and center right) • Huge amounts of freshly deposited sediment was spread across the community by floods and debris flows • December 1999 Source: U. S. Geological Survey, http: //pr. water. usgs. gov/public/venezuela/image_14. html

Mount St. Helens, WA • An eruption sent pumice and ash 14 km (9 mi) into the air, resulting in a lahar (the dark deposit on the snow) flowing from the crater • Some of the lahar flowed to a lake (lower left corner), but most the debris went down the river, as far as 80 km (50 mi) Source: Tom Casadevall, U. S. Geological Survey, • March 1982 http: //vulcan. wr. usgs. gov/Volcanoes/MSH/Images/mudflow_images. html

Experiment to Learn • A debris-flow flume in Oregon provides a laboratory to study landslides • A concrete chute up a hillside (see stairs and windows) • • Drop wet or dry soil and rocks See what happens Measure what happens Try different materials and conditions Source: U. S. Geological Survey, http: //vulcan. wr. usgs. gov/Projects/Mass. Movement/Publications/OFR 92483/OFR 92 -483_inlined. html

Howe Sound, British Columbia, Canada • To prevent future landslide destruction, a retention structure was created • The stream bed was cleared, straightened and deepened above and below the structure • Note the highway crossing at the bottom Source: Copyright © Geology Department, Malaspina University-College, British Columbia, Canada http: //www. mala. bc. ca/~earles/howesound/