scholarly journals Surface Creep Rate of the Southern San Andreas Fault Modulated by Stress Perturbations From Nearby Large Events

2018 ◽  
Vol 45 (19) ◽  
pp. 10,259-10,268 ◽  
Author(s):  
Xiaohua Xu ◽  
Lauren A. Ward ◽  
Junle Jiang ◽  
Bridget Smith‐Konter ◽  
Ekaterina Tymofyeyeva ◽  
...  
Keyword(s):  
Creep Rate ◽  
San Andreas Fault ◽  
San Andreas ◽  
Surface Creep

Creep on the San Andreas fault

1960 ◽  
Vol 50 (3) ◽  
pp. 389-415
Author(s):  
Karl V. Steinbrugge ◽  
Edwin G. Zacher ◽  
Don Tocher ◽  
C. A. Whitten ◽  
C. N. Claire
Keyword(s):  
Creep Rate ◽  
San Andreas Fault ◽  
Total Duration ◽  
Fault Line ◽  
Fault Movement ◽  
Central California ◽  
San Andreas ◽  
Different Types ◽  
Present Rate ◽  
Local Earthquake

ABSTRACT Progressive destruction of buildings and other works of man at the W. A. Taylor Winery near Hollister, California, indicates that one side of a segment of the San Andreas fault is creeping relative to the other. Three different types of measurements all yield an annual rate of creep of approximately one-half inch per year. Steinbrugge and Zacher: Measurements of the separations of pairs of reference marks adjacent to the line of creep have been repeated periodically since 1956, and damage to structures provides a good measure of the total creep since 1948. Reports of damage to older buildings on the same site suggest that the creep may have been going on at about the present rate for fifty or more years. Tocher: Creep recorders designed to measure continuously the differential lateral movement of adjacent sections of the concrete floor have been installed in the main winery building. The creep rate so determined has been about one-half inch per year (with right-lateral sense) for the past two years. Creep accumulates largely in spasms of rather short duration (on the order of a week) separated by intervals of weeks or months during which little or no creep takes place. Ninety-two per cent of the movement in a recent 371-day period accumulated in four spasms of total duration 34 days. Three of these spasms began at times when no local earthquakes were recorded on near-by seismographs; the fourth began with a sudden right-lateral fault movement of 3 mm. at the time of a sharp local earthquake (Richter magnitude 5.0) on January 20, 1960 (GCT). Whitten and Claire: Resurveys over monumented points established near the winery also yield a rate of slippage or creep along the fault line of one-half inch per year. A new method for analyzing the data obtained by retriangulating over monumented points at wide intervals (10 to 20 years) is presented and applied to two triangulation networks which cross the San Andreas fault in central California. Results from a net near Hollister show an average creep rate of about one-half inch per year; results from a net near Cholame (about 75 miles southeast of Hollister) show an average creep rate of about one-tenth inch per year. The results also give an angular value which represents the deformation in the crust adjacent to the fault line.

Observations of creep-related tilt, strain, and water-level changes on the central San Andreas fault

1977 ◽  
Vol 67 (3) ◽  
pp. 641-649 ◽  
Author(s):  
C. E. Mortensen ◽  
R. C. Lee ◽  
R. O. Burford
Keyword(s):  
Water Level ◽  
San Andreas Fault ◽  
Slip Surface ◽  
Lower Boundary ◽  
Water Level Fluctuations ◽  
Fault Creep ◽  
San Andreas ◽  
Strain Data ◽  
Data Source ◽  
Surface Creep

abstract Several simultaneous observations of surface fault creep, tilt, strain, and water-level fluctuations have been recorded along the San Andreas fault in the vicinity of the Almaden-Cienega Winery south of Hollister, California. Creep events recorded on the winery creepmeters on February 16, 1975, and by the winery and Harris Ranch creepmeters on September 17, 1975, were modeled as migrating dislocations with geometries chosen to give results that match the observed tilt and strain data. Source depths for the February 16th and September 17th creep events were found to be relatively shallow, the depth to the lower boundary of the slip surface being 0.4 and 2.0 km, respectively. In both cases slip was found to propagate from the northwest toward the southeast, which is consistent with changes in water level observed in a well near the winery. Since the installation of the tiltmeter and strainmeter 0.8 km northwest of the Cienega Winery, six tilt and strain signals with durations typical of creep events have been related to observed surface creep, while 11 such signals appear unrelated to recorded surface creep. The latter may result from surface creep of limited extent or creep at depth.

Seismicity of northern California and western Nevada

1964 ◽  
Vol 54 (2) ◽  
pp. 845-850
Author(s):  
Mansour Niazi
Keyword(s):  
Fault Zone ◽  
Frequency Distribution ◽  
Seismic Activity ◽  
San Andreas Fault ◽  
Seismic Energy ◽  
Northern California ◽  
Time Intervals ◽  
San Andreas ◽  
Strain Release ◽  
Surface Creep

abstract Nearly 1500 recent northern California and western Nevada earthquakes of magnitude 2 and above have been used to study aspects of the seismicity of the region. In an area covering 512 degrees of latitude by 8 degrees of longitude, each square degree was subdivided into 16 approximately equal quadrilateral blocks. The seismic energy and associated strain release in each block were computed for time intervals up to five years. The computed representations of strain release for each year are contoured to define the distribution of seismic zones in the area and to give a dynamic measure of thier variation. The observed surface creep along the San Andreas fault at the Vineyard seismographic station is compared with the intensity of the seismic activity in the immediate neighborhood of the fault zone. The frequency distribution of earthquakes of different magnitude is discussed.

Deformation near the junction of the creeping and locked segments of the San Andreas fault, Cholame Valley, California (1970-1980)

1983 ◽  
Vol 73 (5) ◽  
pp. 1407-1414
Author(s):  
W. F. Slawson ◽  
J. C. Savage
Keyword(s):  
San Andreas Fault ◽  
Level Line ◽  
Dislocation Model ◽  
Fault Creep ◽  
Slip Rates ◽  
Fault Surface ◽  
Geodetic Networks ◽  
San Andreas ◽  
Elevation Changes ◽  
Surface Creep

Abstract We have constructed a simple dislocation model of the San Andreas fault near Cholame, California, that reproduces the observed deformation of nearby geodetic networks as well as the transition from quasi-continuous slip (fault creep) to a no-slip (locked) condition on the surface trace. The model is specified by the slip rates imposed on the fault surface. Slip on the surface trace is given by the observed fault creep rates, and slip at depths greater than 12.6 km is taken to 30 mm/yr along the entire length of the fault (i.e., beneath creeping and locked sections alike). Slip at intermediate depths is assigned by a rather arbitrary extrapolation of the surface creep values. This postulated distribution of slip on the fault is tested by using it in a dislocation model to predict the deformation in two geodetic networks, a trilateration network (20-km aperture), and a 20-km-long level line. The calculated deformation of the trilateration network agrees with the observed deformation within the observational error. Agreement between the predicted and observed elevation changes along the level line was satisfactory in the sense that the predicted values were below the level of detection, and the observed changes were not significant.

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