Studying Earthquakes

Seismologists are now studying radar images that clearly show surface displacements caused by ground motion at earthquake sites. These displacements can be measured accurately to within a fraction of a centimeter. This image shows surface displacements resulting from the 1994 6.7 magnitude Northridge, California, earthquake. The area was imaged before and after the earthquake by the JERS-1 SAR system. The before and after images were combined with USGS digital elevation models to create the interferogram shown here. In the interferogram, color indicates the amount of surface displacement attributable to the earthquake. This displacement ranges from 0 centimeters (shown in the light purple) to 60 centimeters or just under two feet (shown in the deep red.) LightSAR's Additional Contribution: By monitoring a fault zone after it has experienced an earthquake, scientists may be able to determine whether subsequent earthquakes and aftershocks are adding to or relieving stress. Continuous imaging would allow scientists to pinpoint areas where stress is building, making these areas at risk for future quakes. LightSAR will provide continuous imaging, covering nearly every point on Earth every eight to ten days, for three to five years. In addition, LightSAR will provide higher resolution images, with a millimeter-level surface displacement resolution. This improved resolution will allow very precise monitoring of earth movements. Technical Details Related Links References

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