Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, G.K. Gilbert, U.S. Geological Survey. |
The fence was offset 2.6 m by the magnitude 8.2 earthquake of April 18, 1906, San Francisco, California. The section of the San Andreas fault shown here is 0.8 km north of Woodville. The photo is looking northeast. The lateral or strike-slip fault offset is large; however, the trace is nearly invisible. This earthquake, together with the fire that followed, resulted in more than 3,000 deaths and 400 million dollars of property damage. Note: photo has been colorized. Image Credit: G.K. Gilbert. 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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