Earthquakes in California are A. always above magnitude 7.5, because the San Andreas is such a large fault. B. the result of wid
ening along the San Andreas fault, which will eventually cause western California to sink into the ocean. C. shallow and occur in the upper 15 to 20 km of crust, even though the San Andreas fault cuts through the crust to deeper depths. D. the result of reverse faulting along the San Andreas fault.
C. shallow and occur in the upper 15 to 20 km of crust, even though the San Andreas fault cuts through the crust to deeper depths.
Explanation:
Earthquakes in California usually occur in the upper 15 to 20 km of crust. This is the case even though the San Andreas fault cuts through the crust to deeper depths. The San Andreas fault extends roughly 1,200 kilometers through California, and it forms the tectonic boundary between the Pacific Plate and the North American plate. It is believed that there is significant risk of a major earthquake (greater than 7.0) along this fault, particularly in the southern section of the fault, which is the region along Los Angeles.
