Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, G. Pflafker, U.S. Geological Survey. |
In 1970, an earthquake-induced rock and snow avalanche on Mount Huascaran, Peru, buried the towns of Yungay and Ranrahirca. The death toll from the landslide was 20,000. The avalanche started as a sliding mass of glacial ice and rock. The avalanche swept about 16.5 km to the village of Yungay at a speed of 210-280 km/hr. The fast- moving mass picked up glacial deposits and by the time it reached Yungay, it consisted of 50-100 million m3 of water, mud, and rocks. Image Credit: G. Pflafker. U.S. Geological Survey 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. |
|
