Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, B. Bradley, University of Colorado. |
In 1970, an earthquake-induced rock and snow avalanche on Mt. Huascaran, Peru, buried the towns of Yungay and Ranrahirca. The death toll from the earthquake and landslide was 66,700. The avalanche started as a sliding mass of glacial ice and rock. The avalanche swept about 16.5 km to Yungay at a speed of 210 to 280 km/hr. The fast-moving mass picked up glacial deposits and by the time it reached Yungay, it is estimated to have consisted of about 50 to 100 million m3 of water, mud, and rocks. Image Credit: B. Bradley. University of Colorado The slopes above streams and rivers are subjected to a variety of processes that cause them to recede and retreat from the river or stream channel. These processes, collectively called mass wasting, can be classified according to rapidity of movement and according to the type of materials that are transported. |
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