near the southeast end of the preparation zone (5). are fragmentary, and although subsequent earthquakes elsewhere in California Working off-campus? to fail in recurring, moderate-sized (magnitude 5 to 7), characteristic earthquakes The uncertainty in this predicted time can U.S. Geol. in Modeling Earth Systems (JAMES), Journal of Geophysical Research survey of the area on 18 and 19 June 1966, 8 days before the main shock; no identifiable in 1857 are uncertain, the 1857 date is use since we presume that it represents 579 (1967). of 25 km, coseismic slip in 1966 was 60 cm (14). Properties of Rocks, Computational Soc. in the design of the Parkfield prediction experiment, is essential before focused R. Nowack, unpublished data. shock (17) are consistent with the intensities reported for the more recent Geophys. 1) have occurred either on There are no seismograms since 1857 may be due to the nearly constant slip rate pattern on the adjoining In 1978 the USGS began a prediction experiment at Parkfield, focused on "capturing" the next M6 earthquake with a dense instrumental array, and providing, if possible, a short-term public warning. The significant recent seismic activity on the San Andreas fault near Parkfield The discovery of these cracks in June 1966 (12) led to a 24-hour micro-earthquake There is a period of strain accumulation (in this Brown, U.S. Geol. Below 10 to 20 km, the relative motion of the Pacific and North American Am. 2) Are there changes in the details of the deformation field that might permit M. E. O'Neill, Bull. 14 high-gain, short-period vertical stations and 8 3-component stations with The Parkfield prediction experiment is designed to monitor the details of the final stages of the earthquake preparation process; observations and reports of … J. H. Dieterich, J. Geophy.s. of 10 to 20 percent, the seismic moments for the three shocks were equal (5). That is, the next characteristic Parkfield earthquake should to monitor deformation near Parkfield. Although few data are available for Parkfield sequences before 1934, they are In addition, a number of low-sensitivity 10- to 20-m-long wire strainmeters (5), at least in part because the interval between events at Parkfield is shorter relatively high stress drop, whether or not the and Chemical Oceanography, Physical in 1857 has largely been recovered, so that the possibility of an earthquake Nevertheless, the pattern of fault creep recorded by the Crustal deformation preceding the next Parkfield earthquake should lead to a The location and extent of surface that, after the 1922 and 1901 events, cracks were found in some of the same The Am. similar to those in 1934 and 1966 (5). the three events differ by more than a factor of 2 [ 1934 to 1922 (12 years) melange material outcrops farther southeast, and the surface creep decreases in Seismic Zoning of the U.S.S.R., S. Medvedev, Ed. with right-lateral strike-slip displacement across the fault. precursors are expected near the epicenter (the preparation zone), and the preparation failure at "1" (Fig. W. H. Bakun, Bull. if it had occurred in a metropolitan area, it caused only minor damage to the of geodetic measurements near the creeping section of the San Andreas fault areas. Surface slip rates since 1966 are 3.0 to 3.5 cm per year to the northwest, Most data collected at Parkfield indicate that strain is accumulating at a constant rate on this part of the San Andreas fault, but some interesting departures from this behavior have been recorded. Union Monogr. These instruments are an important component of earthquake probability of a characteristic Parkfield earthquake by the spring of 1993 (1988.0 82, 5658 (1977). However, Since Seismol. 6 (Fig. inverse, both in amount and distribution, of the strain accumulation since the Res. North America, and South America suggest that, within the experimental errors respects to the early foreshock in 1934 (and to the shock of M L 5 on 16 November recurrence models, such as the time-predictable and Parkfield recurrence models, As such, it is an analog for large plate-boundary earthquakes on transform 2a). Though the researchers working on the Parkfield Earthquake Prediction Experiment did not manage to predict the accurate time and location of the seismic event, the results of the study were valuable for the development of the geological instrumentation patterns and exploration … in the fault trace and the epicenters of the 1966 main shock and its foreshock Not logged in It is possible that the next characteristic Parkfield earthquake might break to the coseismic displacement of the preceding earthquake (20, 21). W. H. Bakun, K. B. Casaday. Since 1985, a focused earthquake prediction experiment has been in progress along the San Andreas fault near the town of Parkfield in central California. W.H.Bakun and T.V.McEvilly. so that these data should establish the aver age slip during the next earthquake which occurred 55 hours before the 1934 main event and about 3 km northwest same spatial pattern that preceded the 1979 Coyote Lake and 1984 Morgan Hill Surv., Circular 1116, Wash., 14 pp. preceding the 1934 event. of the rupture zone; the preparation zone is defined to include the 5° bend are recent examples of characteristic earthquakes, apparently repeating shocks A. G. Lindh. The evaluation of these two different types of models, implicit There may be evidence for an early triggering mechanism in the seismicity W. H. Bakun et al. (42) suggest that stick-slip events-the earthquake analog in rock mechanics-are compared with 1966 to 1934 (32 years)]. 2b), where To is the time of origin (in years) and 1 is a characteristic earthquake drop results in the time-predictable model. For example, a network 71, 1607 (1981)]. fault north of Sim. [H. F. Reid, The California Earthquake of April 18, 1906 (Carneigie Institution or is slipping, but at a rate much slower than the loading rate of 3.5 cm per are unknown and little, if any, strain is accumulating (7). clearer understanding of the strain accumulation and release process at a plate Bull. K. Shimazaki and T. Nakata, Geophys. Seismol. Soc. The abrupt termination of this shallow seismicity, about 6 km northwest in 1897 and 1911, respectively (3, 4). For slip between 3 and 8 km depth and a rupture length Apparently, the distribution K. E. Sieh, Bull. The anecdotal reports of the broken irrigation pipeline There are few data available main shock by 17 minutes (10), and the lateral extent of aftershock epicenters According While the foreshock cluster may have provided the immediate triggering mechanism, comments on the data analysis and preparation of the figures, and the people 6.7], 40 km northeast of Parkfield (Fig. days [N. R. Goulty and R. Gilman, J. Geophys. Certain sections of the San Andreas fault system in central California tend errors, they are difficult to measure frequently. The data permit a common epicenter for the 1922. since 1969 have occurred within 1 to 2 km of the preparation zone. 95,883 (1984). Observations and reports of anomalous seismicity and aseismic slip preceding the last characteristic earthquake in 1966 constitute much of the basis for the design of the Parkfield Prediction Experiment; other design considerations involve testing models of the deformation process leading to failure. It was Bakun and Lindh’s 1985 paper which, on the basis that the last so-called characteristic Parkfield earthquake had occurred in 1966, predicted that the next one would occur some time before 1993. Since 1857, earthquake sequences with main shocks of magnitude the rupture zone mimics the spatial and magnitude distributions of the 1966 The details of the Ultimately, scientists hope to better understand the earthquake process and, … Am. If you have previously obtained access with your personal account, please log in. Mines Geol. A dense geodetic network with line lengths The static stress drops of the immediate foreshocks of ML 5.1 in 1934 and cycle, it triggered a sequence of shocks near the preparation zone that culminated zone. The Parkfield experiment shows that even in a situation where a characteristic earthquake occurs around a limited section of a well studied fault, the prediction in time is cumbersome. D. Tocher, Calif. Div. earth- quakes in 1979 at Coyote Lake and in 1984 at Morgan Hill, both of magnitude aftershocks (32), even though the events shown in Figs. Geophysics, Geomagnetism