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U.S. Geological Survey Open-File Report 95-820

Breaks in Pavement and Pipes as Indicators of Range-Front Faulting Resulting from the 1989 Loma Prieta Earthquake near the Southwest Margin of the Santa Clara Valley, California

By Kevin M. Schmidt, Stephen D. Ellen, Ralph A. Haugerud, David M. Peterson, and Geoffrey A. Phelps


Thumbnail of publication and link to PDF (7.7 MB)


Damage to pavement and near-surface utility pipes, caused by the October 17, 1989, Loma Prieta earthquake, provide indicators for ground deformation in a 663 km2 area near the southwest margin of the Santa Clara Valley, California. The spatial distribution of 1284 sites of such damage documents the extent and distribution of detectable ground deformation. Damage was concentrated in four zones, three of which are near previously mapped faults. The zone through Los Gatos showed the highest concentration of damage, as well as evidence for pre- and post-earthquake deformation. Damage along the foot of the Santa Cruz Mountains reflected shortening that is consistent with movement along reverse faults in the region and with the hypothesis that tectonic strain is distributed widely across numerous faults in the California Coast Ranges.

Version 1.0

First posted July 8, 2009

  • Report text PDF (36 pages; 7.7 MB)
  • Plate 1 PDF, Map showing distribution of breaks in pavement and pipes near the southwest margin of the Santa Clara Valley, California (~32" x ~31"; 17.2 MB)
  • Plate 2 PDF, Map showing subset of damage to pavement and pipes near Los Gatos, Cupertino, and Los Altos Hills (~45" x ~29"; 31.8 MB)

This report is available only on the Web

For additional information contact:
Kevin Schmidt

Western Earth Surface Processes Team

This report is presented in Portable Document Format (PDF); at least version 7 of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Schmidt, Kevin M., Ellen, Stephen D., Haugerud, Ralph A., Peterson, David M., and Phelps, Geoffrey A., 1995, Breaks in pavement and pipes as indicators of range-front faulting resulting from the 1989 Loma Prieta Earthquake near the southwest margin of the Santa Clara Valley, California: U.S. Geological Survey Open-File Report 95-820, 33 p., 2 plates, scale 1:62,500 [].





Damage, Methods, and Sources of Information


Categories of Damage





References Cited

two plates

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