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Nearfield interseismic vertical strain on the Central Garlock Fault, southern California, 1984–1991
Author(s) -
Sylvester Arthur Gibbs
Publication year - 1992
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/92gl00753
Subject(s) - geology , fault (geology) , vertical displacement , subsidence , induced seismicity , seismology , tectonics , geodesy , displacement (psychology) , geomorphology , psychology , structural basin , psychotherapist
Repeated precise leveling of fault‐crossing arrays at two sites on the central and western parts of the Garlock fault discloses minor height changes of a few centimeters across the fault in seven years. During that time, the seismicity of the fault has been very low relative to other parts of California. Although other investigators have measured a millimeter or two of horizontal displacement per year near each of the leveling arrays, the vertical changes measured in this study probably result from nontectonic differential subsidence across the fault due to the effects of the 1985–1991 drought in southern California. The vertical displacement at Cameron could turn out to be tectonic, but at the Koehn Lake site the subsidence may be related to nearby pumping of groundwater. The changes and rates of heights reported here should not be extrapolated in time or space, because of the relatively short period of observations, and because these sites measure only minuscule parts of the 250 km‐long fault.