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Comment: 11:29 - 12:49 (01:20)
Source: Annenberg/CPB Resources - Earth Revealed - 25. Living With Earth, Part I
Keywords: "William Bakun", geologist, earthquake, "Loma Prieta Earthquake", fault, "San Andreas Fault", "strike-slip fault", focus, fissure, landslide
Our transcription: As research efforts continue, geologists begin to recognize that there are a number of surprising aspects to this quake.
One of the interesting things about the Loma Prieta Earthquake was that the fault that broke was not the vertical strike-slip fault that we tend to think of as characterizing the San Andreas Fault.
Geologists normally expect the two sides of the San Andreas Fault to slip past each other horizontally with the west side moving to the northwest.
This did, in fact happen, but the west side also moved vertically riding up on the eastside between one and two meters.
What also catches the attention of geologists is that the focus of the quake occurred 18 kilometers beneath the surface surprisingly deep for California earthquakes.
Perhaps because the quake was so deep-seated, no rupture broke the surface along the fault, but numerous fissures resulted form landslides triggered by the shaking.
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