A possible geodetic anomaly observed prior to the Loma Prieta, California, earthquake

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL017i008p01211· OSTI ID:5981045

Lisowski, M; Prescott, W H; Savage, J C; Svarc, J L

Monthly measurements since mid-1981 of distance from a geodetic station located 11 km from the epicenter of the Loma Prieta earthquake (M{sub s} = 7.1; October 17, 1989) to three stations 30 to 40 km distant provides an unusually complete record of deformation in the epicentral region in the years prior to an earthquake. Roughly 1.3 years before the earthquake, at about the time of the first magnitude-5 foreshock, the rate of change in line length for two of the lines appears to change; the rate for the third line does not change. Other similar, though smaller, changes in rate are apparent in the eight-year record. Thus, there is marginal evidence for a change in deformation rate about one year before the Loma Prieta earthquake, but that change need not be a precursor.

• OSTI ID: 5981045
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 17:8; ISSN GPRLA; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CALIFORNIA
DEFORMATION
EARTHQUAKES
FEDERAL REGION IX
FORECASTING
FORESHOCKS
GEODETIC SURVEYS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
NORTH AMERICA
SEISMIC EVENTS
SURVEYS
TECTONICS
USA