What is the probability that an earthquake is a foreshock to a larger earthquake?
Worldwide the probability that an earthquake will be followed within 3 days by a large earthquake nearby is somewhere just over 6%. In California, that probability is about 6%. This means that there is about a 94% chance that any earthquake will NOT be a foreshock. In California, about half of the biggest earthquakes were preceded by foreshocks; the other half were not. At this time, we cannot tell whether or not an earthquake is a foreshock until something larger happens after it... so only in retrospect.
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What is the USGS doing to mitigate and respond to earthquake hazards?
The U.S. Geological Survey performs the following functions related to earthquake hazard mitigation: Receives, analyzes, maintains, and distributes data on earthquake activity worldwide. Satellites link our National Earthquake Information Center in Golden, Colorado to a network of seismograph stations. These stations, located throughout the world, are maintained by the U.S. Geological Survey...
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What is the USGS doing to mitigate and respond to earthquake hazards?
The U.S. Geological Survey performs the following functions related to earthquake hazard mitigation: Receives, analyzes, maintains, and distributes data on earthquake activity worldwide. Satellites link our National Earthquake Information Center in Golden, Colorado to a network of seismograph stations. These stations, located throughout the world, are maintained by the U.S. Geological Survey...
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