Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, Sue Hirschfeld. |
(Left) Fault creep is slowly deforming Berkeley Memorial Stadium, built in 1923 across the Hayward fault. View A provides an overview of the stadium, but creep is not visible in the photo. The crowd is gathered near the location of view B. (Right) Offset of expansion joints and fracturing of the exterior walls of the stadium result from a third of a meter or about 13 inches of fault movement that has deformed the structure. Image Credit: Sue Hirschfeld. Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden rupture associated with an earthquake. It is a usually slow deformation of rock resulting from constant stress being applied over a period of time. Sometimes aseismic slip is observed at the ground surface along a ruptured fault that has produced a substantial earthquake. Examples are from the Hollister and Hayward, California, region. Several of the slides are split images of a location, comparing fault movement over the years. |
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