Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, U.S. Geological Survey. |
Rows in the cultivated field west of El Progresso, Guatemala, deformed by the earthquake of February 4, 1976. The thick, saturated, unconsolidated deposits have yielded by plastic deformation rather than rupture along the left-lateral strike-slip fault. This quake resulted in the deaths of 23,000 people and $1.1 billion dollars in property damage. Image Credit: U.S. Geological Survey Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal movements that have produced mountains and changed continents. Initially a section of Earth's crust may merely bend under pressure to a new position. Or slow movement known as seismic creep may continue unhindered along a fault plane. However stresses often continue to build until they exceed the strength of the rock in that section of crust. The rock then breaks, and an earthquake occurs, sometimes releasing massive amounts of energy. The ensuing earth displacement is known as a fault. This slide set describes the mechanism and types of faulting. It illustrates a variety of fault expressions in natural and manmade features. |
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