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Glossary

earthquake

An earthquake is a sudden motion or shaking of the Earth's crust, caused by the abrupt release of slowly accumulated strain stored in the rocks beneath the surface.

earthquake

About the image: Earthquake of October 15, 1979, El Centro, California. The magnitude 6.9 earthquake caused $30 million property damage and injured 91 people. Here earthquake faulting has caused an offset of rows in a lettuce field near El Centro. Such a fault with purely horizontal displacement to the right as one looks across the fault is known as a right lateral strike slip fault. The agriculture industry suffered heavy losses due to damage to canals, irrigation ditches, and subsurface drain tiles disturbed by the movement along the Imperial Fault.

Image Location: El Centro, California

Image Credit: National Geophysical Data Center
   

    Last Modified: 2005-04-15