Utah's Earthquake Threat: 1983 Borah Peak, Idaho Fault Scarp
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Resource ID
1128
Resource Type
Photo
Title
Utah's Earthquake Threat: 1983 Borah Peak, Idaho Fault Scarp
Author
Bill Lund (Utah Geological Survey)
Publisher
University of Utah Seismograph Stations
Accession
UGS-HB5756
Camera make / model
LS9000 Slide
Caption
If the earthquake is large enough (magnitude 6.5 or greater for the ISB states), movement of blocks of rock along the fault will be enough to rupture the surface of the earth, producing a fresh cliff face or fault scarp. The magnitude 7.3 earthquake that occurred in central Idaho in 1983 produced this new fault scarp 26 miles long and with a maximum displacement of9.8 feet. (Notice that the man is standing on the down thrown block ofrock. There was no opening up.)