Distribution and timing of slip along the Nunez fault after June 11, 1983

Journal Article · Mon Jan 01 04:00:00 EST 1990 · United States Geological Survey, Professional Paper; (USA)

OSTI ID:5668187

Rymer, M J

Nine leveling lines were installed across the Nunez fault near Coalinga, Calif., after the second of five moderate earthquakes occurred on the fault. Surface rupture on two north-south-trending fault segments was associated with the first of these earthquakes on June 11, 1983. The lines were installed to record postseismic-slip and possible later coseismic-slip events. Leveling began July 15, 1983, and was repeated five times, ending August 29, 1984. Horizontal-angle surveys measured the lateral component of postseismic slip along one of these leveling lines from August 10, 1983, to February 12, 1985. Direct measurements of scarp heights and leveling data indicate a complex history for slip on the Nunez fault during the 1983 Coalinga earthquake sequence. Possible minor postseismic slip on the fault followed the June 11 initial surface rupture. On July 22, 41 days after the initial rupture, the largest earthquake on the Nunez fault coincided with a second episode of coseismic surface displacement of more than 3 cm. The July 22 earthquake and its aftershocks either initiated or accelerated postseismic slip along the fault. The July 22 coseismic and postseismic slips were greater at the north ends of both fault segments. The largest surveyed value of July 22 coseismic and postseismic slip was more than 6 cm. The right-lateral component of postseismic slip at one site, starting 60 days after the initial surface rupture, amounted to 9 mm. The proportion of right-lateral to vertical components measured for post-July 22 postseismic slip is similar to that for the June 11 coseismic-slip observations.

• OSTI ID: 5668187
• Journal Information: United States Geological Survey, Professional Paper; (USA), Journal Name: United States Geological Survey, Professional Paper; (USA) Vol. 1487; ISSN XGPPA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AFTERSHOCKS
CALIFORNIA
DEFORMATION
DEVELOPED COUNTRIES
DISTRIBUTION
EARTHQUAKE MAGNITUDE
EARTHQUAKES
FAILURES
FEDERAL REGION IX
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GROUND MOTION
MEASURING INSTRUMENTS
MECHANICS
MOTION
NORTH AMERICA
ROCK MECHANICS
RUPTURES
SEISMIC EFFECTS
SEISMIC EVENTS
SLIP
SURVEYS
TIME DEPENDENCE
USA