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Geological Investigations Relevant to Earthquake Engineering Problems

Allen, Clarence R. (1984) Geological Investigations Relevant to Earthquake Engineering Problems. In: Fundamentals of Geology and Seismology for Earthquake Engineers. Earthquake Engineering Research Institute , Berkeley, Ca, 1-1-1-5.

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Virtually all large earthquakes are caused by sudden movements on faults, which are simply surfaces of shearing within the earth's crust. We know this not only from the observations of surface faulting during large earthquakes, but also from seismological studies indicating that the source mechanism of large earthquakes is indeed an abrupt shearing process and not some other sort of mechanical phenomenon such as implosion or tensile failure. The energy released during large earthquakes demands fault ruptures of significant lengths, with rupture lengths of up to 1000 km being observed during the largest of earthquakes; even a relatively moderate earthquake of magnitude 6 normally requires a fault rupture length of 5-10 km. The largest fault displacements observed at the ground surface during individual historic earthquakes are 11.5 m vertical (Assam, 1897) and 9.9 m horizontal (Mongolia, 1957), although significantly larger individual fault displacements at depth are inferred from some geodetic observations.

Item Type:Book Section
Additional Information:© 1984 Earthquake Engineering Research Institute. Seminar No. 4. Organizer W. W. Hays. Publication No. 84-06.
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ID Code:50358
Deposited By: Kristin Buxton
Deposited On:13 Oct 2014 22:59
Last Modified:03 Oct 2019 07:22

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