Much of Utah and Idaho is situated within the seismically active Intermountain Seismic Belt of the Western United States. This area is marked by numerous historical earthquakes and active fault systems; the Cache Valley faults are active and form a part of this system. Historical seismicity in the Cache Valley area has been low, although there was a period of increased seismic activity between 1961 and 1969. The maximum Richter magnitude to occur during that period was 5.7, recorded in 1962. Faulting in Cache Valley extends from near James Peak, Utah, north to approximately Preston, Idaho, and consists of fault scarps along the western edge of the Bear River Range and a discontinuous zone of faulting at the eastern edge of the Wellsville and Malad ranges. Youthful surface faulting has also been identified within Cache Valley north of Logan, Utah, and within the Bear River Range southeast of Logan. The Cache Valley faults are likely to generate damaging earthquakes in the future, accompanied by surface faulting and strong ground shaking. In the past, major urban areas have developed within land-use planning that accounted for the active fault hazard. Future planning and development in Cache Valley should incorporate geologic and earthquake engineering investigations in order to more accurately define the locations of faults and fault-related geologic hazards for use in planning and design to reduce earthquake risks.

  • Supplemental Notes:
    • This article is an excerpt from the Proceedings of the Fourteenth Annual Engineering Geology and Soils Engineering Symposium that was sponsored by Idaho Transportation Department, Division of Highways; University of Idaho, Department of Geology and Department of Civil Engineering; Idaho State University, Department of Geology and Department of Engineering; and Boise State University, Department of Geology, and Department of Physical Science and Engineering. This symposium was held at the Rodeway Inn, Boise, Idaho, and was hosted by Boise State University.
  • Corporate Authors:

    Idaho Department of Highways

    P.O. Box 7129
    Boise, ID  United States  83707
  • Authors:
    • Glass, C E
    • Brogan, G E
    • Cluff, L S
  • Publication Date: 1976-4-9

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Filing Info

  • Accession Number: 00142673
  • Record Type: Publication
  • Created Date: Feb 1 1977 12:00AM