| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 U.S. Geological Survey
345
Middlefield Road, MS 977
Menlo Park, California
94025
harris{at}usgs.gov
(R.A.H.)
2 Department of Geological
Sciences
Arizona State University
Tempe, Arizona
85287
ramon.arrowsmith{at}asu.edu
(J
R.A.)
 |
Abstract |
|---|
 Top Abstract IntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
|
The Parkfield experiment was designed in the mid- 1980s, at a time when it appeared that similar M 6.0 earthquakes occurred fairly regularly near Parkfield (Bakun and McEvilly, 1984; Bakun and Lindh, 1985). The Parkfield sequence has included M 6.0 earthquakes in 1881, 1901, 1922, 1934, 1966, and 2004 (see Bakun et al. [2005] for information about the magnitudes of the older earthquakes). The 1966 earthquake was carefully examined by field geologists (e.g., Brown et al., 1967) and recorded by strong ground motion and geodetic instruments, and similar to the 2004 event, led to a considerable number of scientific advances (for starters, see the Bulletin of the Seismological Society of America Special Issue on the 1966 earthquake, vol. 57, no. 6, 1967) including basic ideas about earthquake source behavior and the resulting short-term strong ground motions and longer-term postseismic fault behavior.
Many of the expectations for the next Parkfield earthquake following 1966 were based on the known characteristics of its M 6.0 predecessors (Michael and Jones, 1998), such as the epicenter, magnitude, rupture direction, rupture extent, and surface cracking (Bakun and McEvilly, 1984). Although the 2004 event did not fulfill all of these expectations, it was due to this optimism of a potentially predictable earthquake that so many instruments were installed and maintained in place to capture the 2004 event.
In this article we discuss some of the new advances brought to light by the 2004 earthquake and the Parkfield Earthquake Prediction Experiment. We also encourage the reader to consult comprehensive overviews of the Parkfield Earthquake Prediction Experiment by Roeloffs and Langbein (1994) and Roeloffs (2000), and preliminary reviews of data generated by the 2004 Parkfield earthquake by Bakun et al. (2005), Bilham (2005), Langbein et al. (2005), and Shakal et al. (2005). In Table 1 we list the articles included in the special issue and the general subject areas that they cover.
|
|
Results and Discussion |
|---|
|
TopAbstractIntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
Earthquake interaction effects have been explored as an explanation for the time delay of the Parkfield earthquake. Stress change effects due to the nearby 1983 M 6.4 Coalinga earthquake have been credited with delaying the Parkfield earthquake by up to a few years (Simpson et al., 1988; Toda and Stein, 2002). However, even with this delay, the occurrence of the most recent M 6.0 earthquake in 2004 is still inconsistent with the time-predictable model. It has also been proposed that interaction effects due to the distant M 7.9 1906 and nearby M 7.9 1857 earthquakes have modulated the timing of M 6.0 Parkfield earthquakes (Ben-Zion et al., 1993). While intriguing, this idea may need more features to explain why the times between successive Parkfield M 6.0 have not been progressively longer (i.e., this idea works well for the successively longer 1934–1966 and 1966–2004 time intervals, but does not explain why a short interval suddenly appeared from 1922 to 1934, following longer intervals from 1881 to 1901 and 1901 to 1922). Alternatively, this idea of lengthening interevent times may be consistent if additional earthquakes in the surrounding region are considered (Toppozada and Branum, 2006).
Similar to the time-predictable model, the slip-predictable earthquake model also appears unsatisfactory at Parkfield (Bakun and McEvilly, 1984; Jackson and Kagan, 2006; Lienkaemper et al., 2006; Murray and Langbein, 2006; Toké and Arrowsmith, 2006). In the slip-predictable model a fixed lower level of fault strength sets the slip in the next earthquake to be determined by the amount of time that has elapsed since the last earthquake. According to the slip- predictable model, much more slip should have occurred in the 2004 Parkfield earthquake, leading to a larger magnitude event than the actual M 6.0 (e.g., Harris and Archuleta, 1988; Arrowsmith et al., 1997; Murray and Langbein et al., 2006).
Given that the San Andreas fault zone in the Parkfield region also releases some of its energy aseismically (fault slip without generation of seismic waves) in addition to seismically (fault slip with generation of seismic waves), some investigators have calculated the energy budget by including the aseismic slip that occurs right after Parkfield earthquakes. The addition of the aseismic slip does make a significant difference in the magnitude of the total slip events at Parkfield (Murray and Segall, 2005; Johanson et al., 2006; Johnson et al., 2006; Langbein et al., 2006; Murray and Langbein, 2006; Toké and Arrowsmith, 2006), but still does not satisfy the slip-predictable model. This earthquake is the first time that slip as a function of time has been imaged in detail, due to the extensive Parkfield Earthquake Prediction Experiment networks of strong ground motion stations, creep meters, alignment arrays, and GPS stations at frequencies starting at 1 Hz. However, even with this detailed imaging, it is still clear that the substantial postseismic slip following M 6.0 Parkfield earthquakes does not catch the shallower parts of the fault up to the longer-term slip rates of the deeper parts of the San Andreas fault. Instead, the largest earthquakes on the fault, such as the M 7.9 1857 Ft. Tejon event, likely dominate in the energy equation (Toké and Arrowsmith, 2006).
Time-predictable or slip-predictable models are sometimes featured elements in earthquake hazard assessments (e.g., Jackson and Kagan, 2006). Because M 6.0 earthquakes at Parkfield fit neither time nor slip-predictable models of earthquake recurrence, the question is if these recurrence concepts should be applied elsewhere. One could argue that M 6.0 earthquakes are not the largest events that occur in the Parkfield region, instead M 7.9–M 8 events dominate the strain budget, so perhaps these largest events are what should be tested instead. A challenge is that the most recent M 7.9 earthquake thought to have started at Parkfield is not clearly revealed in the paleoseismic trenches at Parkfield (Toké et al., 2006), but major slip is apparent southeast of Parkfield along the fault (Grant and Sieh, 1993, 1994; Young et al., 2002).
The gradient in interseismic slip and slip deficit along the Parkfield segment (e.g., Murray et al., 2006; Toké and Arrowsmith, 2006) may suggest that while the segmentation concept works in that the Parkfield segment contained the 2004 event, it does not work so well in that the 1857 event may have ruptured into the southern portion of the segment (slip measurements of Sieh, [1978a,b] and Lienkaemper [2001]). However, the exposures of Toké et al. (2006) can be interpreted by repeating moderate earthquakes and creep in the Parkfield area and do not require large (multimeter) surface rupture, so perhaps 1857 terminated somewhere between Highway 46 and the town of Parkfield (e.g., Lienkaemper et al., 2006; Toké and Arrowsmith, 2006).
Paleoseismic investigations even farther southeast on the San Andreas fault, at Wrightwood, reveal irregular earthquake recurrence, and it has been posited that these events also do not fit the simple times or slip-predictable models (Weldon et al., 2004). Because these investigations are point measurements and the amount of slip per event is often unknown, future study is needed to help resolve the issue. In the case of Parkfield, this includes more coverage along the main San Andreas fault as well as information on the paleoseismic behavior of the Southwest Fracture Zone.
Precursors
The utility of short-term earthquake prediction has been proposed by some yet
dismissed by others in the scientific community. This type of prediction might
involve precursory signals that could alert scientists and the public seconds to
days in advance of a pending earthquake hazard. With this goal in mind, numerous
sensors were deployed at Parkfield to record potential precursory signals. The
instruments included water wells, high-resolution strain, electric field,
magnetic field, and seismic-wave detectors. It appears that nothing unusual
(statistically significant) was recorded before the 2004 Parkfield mainshock
(Bakun et al., 2005;
Borcherdt et al., 2006;
Johnston et al., 2006a,b).
Unlike the previous two Parkfield M 6.0 earthquakes in 1934 and 1966, but
similar to the M 6.0 Parkfield earthquakes in 1901 and 1922, there were
no M 5 foreshocks in 2004, and no other notable precursory signals were
recorded on any of the sensors.
Even without precursory signals, measurements before, during, and after a mainshock provide constraints on nucleation and subsequent earthquake processes. For example, the Parkfield data provide good comparisons among the various types of coseismic and postseismic signals caused by the M 6.0 earthquake (Johnston et al. 2006b). The Parkfield data also provide constraints on the nucleation process during the mainshock. Johnston et al. (2006a) find that the nucleation zone was probably smaller than 30 m in size and released less moment than a M 2.2 earthquake.
Ground Motions
The M 6.0 Parkfield earthquake produced highly variable patterns of
ground motions in the near-field region
(Shakal et al., 2005,
2006a;
Borcherdt et al., 2006;
Fletcher et al., 2006;
Wang et al., 2006). The
highest recorded ground motions were greater than 2g acceleration and
80 cm/sec velocity in the fault-normal direction on a soil site station, Fault
Zone 16
(Shakal et al., 2006b).
This peak acceleration is among the highest ever recorded.
Bakun et al. (2005), Shakal et al. (2006a), and Wang et al. (2006) compare the Parkfield ground-motion recordings with some of the ground-motion attenuation relations currently in use. The attenuation relations are measures of how ground motions change with distance from a fault. The attenuation relations appear consistent with the Parkfield data, in terms of both the median values and the variability, but the high ground motion at FZ16 (Shakal et al., 2006b) demonstrate why one should not be truncating the ground- motion distribution at one or two sigma in the attenuation relations (Norm Abrahamson, personal comm., 2006). Additionally, the wide range of ground motion recorded at Parkfield in the near-field (Fletcher et al., 2006 Shakal et al., 2006a,b; Wang et al., 2006) emphasize why it is necessary to use a probabilistic approach for design ground motions (Norm Abrahamson, personal comm., 2006).
Source, path, and site effects all played important roles in determining the ground motions produced by the 2004 Parkfield earthquake. Stations that were in place during 2004, as well as during earlier events, such as the 1983 M 6.4 Coalinga earthquake and 2003 M 6.5 San Simeon earthquake (Hardebeck et al., 2004), were often, but not always, affected differently by each earthquake. Liu et al. (2006), Shakal et al. (2006a,b), and Wang et al. (2006) discuss these interearthquake comparisons. Fletcher et al. (2006) and Wang et al. (2006) note the marked near-field variability among the close stations in the U.S. Geological Survey Parkfield Dense Seismograph Array (UPSAR) that recorded the 2004 mainshock and show how detailed features of the path (i.e., velocity structure of the fault region and the ground surface topography) in addition to the source, affected the ground motions. Clearly probabilistic approaches will be necessary to forecast the ground-motion variability caused by all future large earthquakes (Norm Abrahamson, personal comm., 2006).
Source Behavior
The coseismic slip during the 2004 mainshock was observed geologically at the
Earth’s surface
(Lienkaemper et al., 2006,
Rymer et al., 2006) and
inferred at depth using surface slip, creep, alignment array, GPS,
INSAR, strong ground motion, strain, and magnetic data
(Borcherdt et al., 2006;
Custodio et al., 2005;
Fletcher et al., 2006;
Johanson et al., 2006;
Langbein et al., 2006;
Lienkaemper et al., 2006;
Liu et al., 2006;
Murray and Langbein, 2006;
Mena et al., 2006).
Constraints on the geodetic models for deep slip were assisted by estimates of
slip rates for the creeping section to the north
(Titus et al., 2006).
It should be noted that the Parkfield earthquake is probably the first time that
such a comprehensive geodetic data set has been recorded for a mainshock and its
immediate postseismic period. These data sets, along with the newly revealed
geometry
(Simpson et al., 2006
Thurber et al., 2006)
and velocity structure of the fault of the San Andreas fault zone in this region
(Cochran et al., 2006;
Li et al., 2006;
Thurber et al., 2006)
have allowed for an unprecedented view of an M 6.0 earthquake, and the
mechanical transition of a fault and its surroundings into the postseismic
period.
Inclusion of detailed fault zone geometry allowed Murray and Langbein (2006) to show temporal migration of slip from one fault strand to another. Availability of high-rate GPS and strain data allowed for investigations of the transition from coseismic to postseismic response of the fault zone (Johnson et al., 2006; Langbein et al., 2006). Unlike some earthquakes where postseismic slip may be a small fraction of the mainshock, at Parkfield the postseismic slip was revealed to be comparable to that of the mainshock (e.g., Johanson et al., 2006; Johnson et al., 2006; Langbein et al., 2006; Murray and Langbein, 2006). Similar behavior was suspected for previous M 6.0 Parkfield earthquakes, and sizeable afterslip was observed at the earth’s surface following the 1966 event (e.g., Allen and Smith, 1966), but before 2004 the geodetic data did not allow separation of the (deep) mainshock slip from comingled mainshock and postseismic slip, due to less frequent (and more difficult to collect) geodetic measurements in earlier decades.
Using the high-rate GPS and strain data from the 2004 Parkfield earthquake, Langbein et al. (2006) and Johnson et al. (2006) analyzed the transition from coseismic to postseismic periods. Langbein et al. (2006) determined that the observed behavior from 100 sec to 9 months following the 2004 mainshock is consistent with creep models for elastic solids. Johnson et al. (2006) looked at possible afterslip, poroelastic, and viscoelastic effects. They determined that rate-state friction and a simple model of afterslip on the fault plane fits the postseismic data in the first few months following the 2004 earthquake.
Comparisons of the strong-motion-derived models for the 2004 mainshock and the geodetically inferred models show some similarities and some differences. It should be noted though that the two data sets have different resolving capabilities that partly depend on each network’s spatial coverage on the Earth’s surface. Overall, a comparison of the geodetic and seismological models image the major coseismic slip occurring northwest of the Gold Hill hypocenter (Custodio et al., 2005; Johanson et al., 2006; Johnson et al., 2006; Liu et al., 2006; Murray and Langbein, 2006). Discrepancies include whether or not major slip also occurred at the hypocenter, with the strong ground motion inversion and forward modeling (Custodio et al., 2005; Liu et al., 2006; Shakal et al., 2006a) inferring considerable slip at the hypocenter, and the high-rate of sampling geodetic inversions not imaging slip at the hypocenter (Johnson et al., 2006; Langbein et al., 2006; Murray and Langbein, 2006). Interestingly, the study by Johanson et al. (2006) that included lower frequency GPS, in addition to INSAR data, did image slip at the hypocenter. It is quite possible that these differences may be reconciled with a look at the temporal and spatial station resolution, as demonstrated in models by Langbein et al. (2006), and Johnson et al. (2006) that force slip to occur at the hypocenter and still satisfactorily fit the geodetic data. This question may be solved with joint strong- motion/geodetic-data inversions that carefully consider the resolving capabilities of each data set. Future work may also consider a more accurate fault geometry model in the ground-motion inversions, as was done for the geodetic inversions by Murray and Langbein (2006).
Rupture extent was one part of the successful definition of Parkfield
earthquakes outlined by
Michael and Jones (1998) for the
Parkfield source, with the expectation that the M 
5.7 earthquake(s)
following 1966 would repeat certain aspects of the 1966 mainshock and its
M 6.0 predecessors. Fortunately for the
Michael and Jones (1998)
definition, they, unlike
Bakun and McEvilly (1984) and
Bakun and Lindh (1985) did not
assume a rupture propagation direction to the southeast. The 2004 earthquake,
although it appeared similar to its predecessors in 1922, 1934, and 1966 at
teleseismic distances
(Dost and Haak, 2006), appears
to have primarily ruptured to the northwest, with perhaps a bilateral component
of short southeast rupture
(Custodio et al., 2005;
Liu et al., 2006;
Shakal et al., 2006a).
There has been some debate (with one viewpoint represented by
Ben-Zion [2006] and the
other viewpoint represented by
Harris and Day [2005,
2006] and
Xia et al. [2005])
about whether or not the 2004 earthquake should have propagated either to the
northwest or bilaterally, considering the material contrast across the fault
zone revealed by
Eberhart-Phillips and Michael (1993)
and
Thurber et al. (2006).
However, theoretical studies by
Harris and Day (1997,
2005) and
Andrews and Harris (2005) of the
behavior of an earthquake rupture near a material contrast show the 2004
Parkfield earthquake to be fully consistent with our physics-based
understandings of earthquake behavior. Earthquake ruptures depend on not just
the material properties of the surrounding rocks, but also depend on the fault
geometry, fault friction, and perhaps most importantly, the state of stress on
the fault (Harris, 2004;
Andrews and Harris, 2005).
Li et al. (2006) and Cochran et al. (2006) image the state of the fault zone itself and the surrounding medium before and after the 2004 earthquake, and Shcherbakov et al. (2006) examine how the fault region responds temporally with background seismicity and aftershocks. The Li et al. (2006) Parkfield study, in conjunction with similar analyses of earthquake effects on other faults (e.g., Li et al., 1998, 2003) provides tantalizing clues about how fault zones are damaged then gradually recover after each large earthquake.
Fault Geometry and Long-Term Behavior of the San Andreas Fault near Parkfield
Bakun et al. (2005),
Langbein et al. (2005),
and
Thurber et al. (2006)
reveal an updated 3D view of the San Andreas fault zone in the Parkfield region.
They used seismic data from the dense network of Parkfield seismometers,
included the 1966 aftershock data of
Eaton et al. (1970),
and applied new methods for relocating earthquakes. The updated picture shows
that 1966 aftershocks, background seismicity, and 2004 aftershocks are
superimposed
(Thurber et al., 2006),
indicating that certain locations on the fault fail repeatedly in small
earthquakes. This view of the San Andreas is in agreement with that by
Waldhauser et al. (2004)
who imaged the 1969–2002 background seismicity and
Eberhart- Phillips and Michael (1993)
who imaged the 1966 aftershocks and the background seismicity. The observation
of stable microseismicity patterns may disagree with stress change models that
predict small earthquake locations purely on the basis of stress changes due to
neighboring previous earthquakes (e.g., see
Harris [1998],
Stein [1999], and
Steacy et al. [2005]
for overview discussions of stress- change calculations). This point, touched
upon briefly by
Thurber et al. (2006),
is a topic for continued study.
One use of the newly relocated microseismicity presented by Thurber et al. (2006) is to study fault zone structure and evolution. Simpson et al. (2006) performed such an analysis and imaged the San Andreas fault zone as a single fault zone at greater than 6-km depth that then transitions to two faults above 6-km depth, the San Andreas fault, and the Southwest Fracture Zone (see Simpson et al., 2006). The Simpson et al. (2006) image of the single fault plane at depths greater than 6 km agrees with the earlier study of Eberhart-Phillips and Michael (1993). Murray and Langbein (2006) used the Simpson et al. (2006) complex fault geometry in their geodetic modeling of coseismic and postseismic fault slip. This enabled Murray and Langbein (2006) to image the temporal and spatial evolution of the fault slip on the different near-surface strands.
Simpson et al. (2006) used the distribution of relocated aftershocks to suggest that the Cholame Valley step-over does not persist to depths greater than 6 km. This step-over has been invoked in previous attempts to explain what does or does not stop Parkfield earthquakes (Lindh and Boore, 1981; Harris and Day, 1999). Instead of a classic pull-apart, Simpson et al. (2006) argue that in the near surface in the Parkfield region the San Andreas fault surface is being warped to the northeast over geologic time. This deformation is the result of anelastic (plastic) deformation at shallow depths as the locked section of the fault to the southeast of Parkfield and the creeping section of the fault to the northwest of Parkfield interact, deforming the fault surface in the process. The Simpson et al. (2006) model foresees the Southwest Fracture Zone as an increasingly prominent player in San Andreas earthquakes as the principal fault surface readjusts into a simpler, straighter geometry. This pattern of activation and deactivation of adjacent fault surfaces along the San Andreas fault zone at Parkfield is also manifest at long timescales as shown in geologic mapping of Middle Mountain and vicinity (e.g., Sims, 1990; Rymer et al., 2003; Thayer et al., 2004; Thayer, 2006). These studies show that a major fault generally along strike with the Southwest Fracture Zone has accommodated significant long-term slip (in order to juxtapose granites and volcanic rocks of the Pinnacles–Neenach tie [Sims, 1990; Thayer, 2006]), and that there are numerous San Andreas fault-parallel fault surfaces within a couple kilometers of the active San Andreas fault trace that have been active since the Pliocene.
|
Conclusions |
|---|
|
TopAbstractIntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
|
Acknowledgments |
|---|
|
TopAbstractIntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
Manuscript received May 9, 2006
|
References |
|---|
|
TopAbstractIntroductionResults and DiscussionConclusionsAcknowledgmentsReferences |
|---|
Allen, C. R., and S. W. Smith (1966). Parkfield earthquakes of June 27– 29, 1966, Monterey and San Luis Obispo counties, California—preliminary report, pre-earthquake and post-earthquake surficial displacements, Bull. Seism. Soc. Am.56 ,966 –967.[Web of Science][GeoRef]
Andrews, D. J., and R. A. Harris (2005). The wrinkle-like slip pulse is not important in earthquake dynamics, Geophys. Res. Lett.32 , L23303, doi10.1029/2005GL023996 .[CrossRef]
Andrews, D. J., and R. A. Harris (2006). Reply to comment by Y. Ben- Zion on "The wrinkle-like slip pulse is not important in earthquake dynamics," Geophys. Res. Lett.33 , L06311, doi10.1029/2006GL025743 .[CrossRef]
Arrowsmith, R., K. McNally, and J. Davis (1997). Potential for earthquake rupture and M 7 earthquakes along the Parkfield, Cholame, and Carrizo segments of the San Andreas fault, Seism. Res. Lett. 68,902 – 916.
Bakun, W. H., and A. G. Lindh (1985). The Parkfield,
California, earthquake prediction experiment, Science229
,619
–624.
Bakun, W. H., and T. V. McEvilly (1984). Recurrence models and Parkfield, California earthquakes, J. Geophys. Res. 89,3051 –3058.[CrossRef][Web of Science]
Bakun, W. H., B. Aagaard, B. Dost, W. L. Ellsworth, J. L. Hardebeck, R. A. Harris, C. Ji, M. J. S. Johnston, J. Langbein, J. J. Lienkaemper, A. J. Michael, J. R. Murray, R. M. Nadeau, P. A. Reasenberg, M. S. Reichle, E. A. Roeloffs, A. Shakal, R. W. Simpson, and F. Waldhauser (2005). Implications for prediction and hazard assessment from the 2004 Parkfield earthquake, Nature437 ,969 –974, doi10.1038/ nature04067 .[CrossRef][Medline]
Ben-Zion, Y. (2006). Comment on "Material contrast does not predict earthquake rupture propagation direction," by R. A. Harris and S. M. Day, Geophys. Res. Lett.33 , L13310, doi:10.1029/2005GL025652
Ben-Zion, Y., J. R. Rice, and R. Dmowska (1993). Interaction of the San Andreas fault creeping segment with adjacent great rupture zones, and earthquake recurrence at Parkfield, J. Geophys. Res. 98,2135 –2144.
Bilham, R. (2005). Coseismic strain and the transition to surface afterslip recorded by creepmeters near the 2004 Parkfield epicenter, Seism. Res. Lett.76 ,49 –57.
Borcherdt, R. D., M. J. S. Johnston, G. Glassmoyer, and C. Dietel
(2006). Recordings of the Parkfield 2004 earthquake on the GEOS
array: implications for earthquake precursors, fault rupture, and coseismic
strain changes, Bull. Seism. Soc. Am.96
, no. 4B,S73
–S89.
Brown, R. D.Jr., J. G. Vedder, R. E. Wallace, E. F. Roth, R. F. Yerkes, R. O. Castle, A. O. Waananer, R. W. Page, and J. P. Eaton (1967). The Parkfield-Cholame, California earthquakes of June–August 1966—Surface geologic effects, water-resources aspects, and preliminary seismic data, U.S. Geol. Surv. Prof. Paper 579, 66 pp.
Bufe, C. G., P. W. Harsh, and R. O. Burford (1977). Steady-state seismic slip—A precise recurrence model, Geophys. Res. Lett. 4,91 –94.[Web of Science][GeoRef]
Cochran, E. S., Y.-G. Li, and J. E. Vidale (2006).
Anisotropy in the shallow crust observed around the San Andreas fault before and
after the 2004 M 6.0 Parkfield earthquake, Bull. Seism. Soc.
Am. 96, no. 4B,S364
– S375.
Custódio, S., P. Liu, and R. J. Archuleta (2005). The 2004 Mw 6.0 Parkfield, California, earthquake: inversion of near-source ground motion using multiple data sets, Geophys. Res. Lett. 32,L23312 , doi10.1029/ 2005GL024417 .[CrossRef]
Dost, B., and H. W. Haak (2006). Comparing waveforms by
digitization and simulation of waveforms for four Parkfield earthquakes observed
in station DBN, the Netherlands, Bull. Seism. Soc. Am.96
, no. 4B,S50
–S55.
Eaton, J. P., M. E. O’Neill, and J. N. Murdock
(1970). Aftershocks of the 1966 Parkfield–Cholame, California
earthquake: a detailed study, Bull. Seism. Soc. Am.60
,1151
–1197.
Eberhart-Phillips, D., and A. J. Michael (1993). Three-dimensional velocity structure, seismicity, and fault structure in the Parkfield region, central California, J. Geophys. Res.98 ,15,737 –15,758.
Fletcher, J. B., P. Spudich, and L. M. Baker (2006).
Rupture propagation of the 2004 Parkfield, California, earthquake from
observations at the UPSAR array, Bull. Seism. Soc.
Am. 96, no. 4B,S129
–S142.
Goel, R. K., and C. B. Chadwell (2004). Preliminary report on September 28, 2004 Parkfield earthquake, Earthquake Engineering Research Institute, Oakland, California, www.eeri.org/lfe/pdf/usa_parkfield_goel.pdf. (last accessed June 2006).
Grant, L. B., and K. Sieh (1993). Stratigraphic evidence
for seven meters of dextral slip on the San Andreas fault during the 1857
earthquake in the Carrizo Plain, Bull. Seism. Soc. Am.83
,619
–635.
Grant, L. B., and K. Sieh (1994). Paleoseismic evidence of clustered earthquakes on the San Andreas fault in the Carrizo Plain, California, J. Geophys. Res.99 ,6819 –6841.[CrossRef]
Hardebeck, J. L., J. Boatwright, D. Dreger, R. Goel, V. Graizer, K. Hudnut, C. Ji, L. Jones, J. Langbein, J. Lin, E. Roeloffs, R. Simpson, K. Stark, R. Stein, and J. C. Tinsley (2004) Preliminary report on the 22 December 2003 M 6.5 San Simeon, California, Earthquake, Seism. Res. Lett.75 ,155 –172.
Harris, R. A. (1998). Stress triggers, stress shadows, and implications for seismic hazard, introduction to the special issue, J. Geophys. Res.103 ,24,347 –24,358.[CrossRef]
Harris, R. A. (2004). Numerical simulations of large earthquakes: dynamic rupture propagation on heterogeneous faults, Pure Appl Geophys.161 , no. 11/12,2171 –2181, doi10.1007/s00024-004-2556-8 .[CrossRef]
Harris, R. A., and R. J. Archuleta (1988). Slip budget and potential for a M7 earthquake in central California, Geophys. Res. Lett. 15,1215 – 1218.[CrossRef][Web of Science][GeoRef]
Harris, R. A., and S. M. Day (1997). Effects of a
low-velocity zone on a dynamic rupture, Bull. Seism. Soc.
Am. 87,1267
–1280.
Harris, R. A., and S. M. Day (1999). Dynamic 3D simulations of earthquakes on en echelon faults, Geophys. Res. Lett. 26,2089 –2092.[CrossRef][Web of Science][GeoRef]
Harris, R. A., and S. M. Day (2005). Material contrast does not predict earthquake rupture propagation direction, Geophys. Res. Lett. 32,L23301 , doi10.1029/2005GL023941 .[CrossRef]
Harris, R. A., and S. M. Day (2006). Reply to "Comment on ‘Material contrast does not predict earthquake rupture propagation direction,’ by Y. Ben-Zion," Geophys. Res. Lett. 33, L13311, doi 10.1029/2006GL026811 .
Harris, R. A., and P. Segall (1987). Detection of a locked zone at depth on the Parkfield, California segment of the San Andreas fault, J. Geophys. Res.92 ,7945 –7962.
Hickman, S., M. Zoback, and W. Ellsworth (2004). Introduction to special section: preparing for the San Andreas fault observatory at depth, Geophys. Res. Lett.31 , L12S01, doi10.1029/20046L020688 .[CrossRef]
Jackson, D. D., and Y. Y. Kagan (2006). The 2004
Parkfield earthquake, the 1985 prediction, and characteristic earthquakes:
lessons for the future, Bull. Seism. Soc. Am.96
, no. 4B,S397
–S409.
Jennings, C. W. (1977). Geologic map of California, California Division of Mines and Geology, Geologic Data Map No. 2, scale 1:750,000.
Johanson, I. A., E. J. Fielding, F. Rolandone, and R. Bürgmann
(2006). Coseismic and postseismic slip of the 2004 Parkfield
earthquake from space-geodetic data, Bull. Seism. Soc.
Am. 96, no. 4B,S269
–S282.
Johnson, K. M., R. Bürgmann, and K. Larson (2006).
Frictional properties on the San Andreas fault near Parkfield, California
inferred from models of afterslip following the 2004 earthquake,
Bull. Seism. Soc. Am.96
, no. 4B,S321
–S338.
Johnston, M. J. S., R. D. Borcherdt, A. T. Linde, and M. T. Gladwin
(2006a). Continuous borehole strain and pore pressure in the near-
field of the 28 September 2004, M 6.0 Parkfield, California, earthquake:
implications for nucleation, fault response, earthquake prediction, and tremor,
Bull. Seism. Soc. Am.96
, no. 4B,S56
–S72.
Johnston, M. J. S., Y. Sasai, G. D. Egbert, and R. J. Mueller
(2006b). Seismomagnetic effects from the long-awaited 28 September
2004, M 6.0 Parkfield earthquake, Bull. Seism. Soc.
Am. 96, no. 4B,S206
– S220.
Langbein, J., R. Borcherdt, D. Dreger, J. Fletcher, J. L. Hardebeck, M. Hellweg, C. Ji, M. Johnston, J. R. Murray, and R. Nadeau (2005). Preliminary report on the 28 September 2004, M 6.0 Parkfield, California earthquake, Seism. Res. Lett.76 ,10 –26.
Langbein, J., J. R. Murray, and H. A. Snyder (2006).
Coseismic and initial postseismic deformation from the 2004 Parkfield,
California, earthquake, observed by Global Positioning System, Electronic
Distance Meter, creepmeters, and borehole strainmeters, Bull. Seism.
Soc. Am. 96, no. 4B,S304
–S320.
Lees, J. M., and C. Nicholson (1993). Three-dimensional
tomography of the 1992 Southern California earthquake sequence: constraints on
dynamic earthquake rupture? Geology21
,387
–390.
Li, Y.-G., P. Chen, E. S. Cochran, J. E. Vidale, and T. Burdette
(2006). Seismic evidence for rock damage and healing on the San
Andreas fault associated with 2004 M 6.0 Parkfield earthquake,
Bull. Seism. Soc. Am.96
, no. 4B,S349
–S363.
Li, Y. G., J. E. Vidale, K. Aki, F. Xu, and T. Burdette (1998). Evidence of shallow fault zone strengthening after the 1992 M 7.5 Landers, California, earthquake, Science279 ,217 –219.[CrossRef][Web of Science][GeoRef]
Li, Y. G., J. E. Vidale, S. M. Day, D. D. Oglesby, and E. Cochran
(2003). Post-seismic fault healing on the 1999 M 7.1
Hector Mine, California earthquake, Bull. Seism. Soc.
Am. 93,854
–869.
Lienkaemper, J. J. (2001). 1857 Slip on the San Andreas
fault southeast of Cholame, California, Bull. Seism. Soc.
Am. 91,1659
–1672.
Lienkaemper, J. J., B. Baker, and F. S. McFarland
(2006). Surface slip associated with the 2004 Parkfield,
California, earthquake measured on alinement arrays, Bull. Seism.
Soc. Am. 96, no. 4B,S239
–S249.
Lindh, A. G., and D. M. Boore (1981). Control of rupture
by fault geometry during the 1966 Parkfield earthquake, Bull. Seism.
Soc. Am. 71,95
– 116.
Liu, P., S. Custodio, and R. J. Archuleta (2006).
Kinematic inversion of the 2004 M 6.0 Parkfield earthquake including an
approximation to site effects, Bull. Seism. Soc. Am.96
, no. 4B,S143
–S158.
Mena, B., E. Durukal, and M. Erdik (2006). Effectiveness
of hybrid Green’s function method in the simulation of near field strong
motion: an application to the 2004 Parkfield earthquake, Bull. Seism.
Soc. Am. 96, no. 4B,S183
–S205.
Michael, A. J., and D. Eberhart-Phillips (1991).
Relations among fault behavior, subsurface geology, and three-dimensional
velocity models, Science253
,651
–654.
Michael, A. J., and L. M. Jones (1998). Seismicity alert
probabilities at Parkfield, California, revisited, Bull. Seism. Soc.
Am. 88,117
–130.
Murray, J., and J. Langbein (2006). Slip on the San
Andreas fault at Parkfield, California, over two earthquake cycles and the
implications for seismic hazard, Bull. Seism. Soc. Am.96
, no. 4B,S283
–S303.
Murray, J., and P. Segall (2002). Testing time-predictable earthquake recurrence by direct measurement of strain accumulation and release, Nature419 ,287 –291, doi10.1038/nature00984 .[CrossRef][GeoRef]
Murray, J. R., and P. Segall (2005). Spatiotemporal evolution of a transient slip event on the San Andreas fault near Parkfield, California, J. Geophys. Res.110 , B09407, doi10.1029/2005JB003651 .[CrossRef]
Murray, J. R., P. Segall, P. Cervelli, W. Prescott, and J. Svarc (2001). Inversion of GPS data for spatially variable slip-rate on the San Andreas fault near Parkfield, California, Geophys. Res. Lett.28 , 359– 362.[CrossRef][Web of Science][GeoRef]
Roeloffs, E. (2000). The Parkfield, California earthquake experiment: an update in 2000, Current Sci.79 , no. 9,1226 –1236.
Roeloffs, E., and J. Langbein (1994). The earthquake prediction experiment at Parkfield, California, Rev. Geophys. 32,315 –336.[CrossRef]
Rymer, M. J., R. D. Catchings, and M. R. Goldman (2003). Structure of the San Andreas fault zone as revealed by surface geologic mapping and high-resolution seismic profiling near Parkfield, California, Geophys. Res. Abs.5 ,13,523 .
Rymer, M. J., J. C. Tinsley, J. A. Treiman, J R. Arrowsmith, K. B. Clahan, A. M. Rosinski, W. A. Bryant, H. A. Snyder, G. S. Fuis, N. Toké, and G. W. Bawden
(2006). Surface fault slip associated with the 2004 Parkfield,
California, earthquake, Bull. Seism. Soc. Am.96
, no. 4B,S11
–S27.
Schorlemmer, D., and S. Wiemer (2005). Microseismicity data forecast rupture area, Nature434 ,1086 .[CrossRef][Medline]
Segall, P., and R. A. Harris (1986). Slip deficit on the
Parkfield, California section of the San Andreas fault as revealed by the
inversion of geodetic data, Science233
,1409
–1413.
Segall, P., and R. Harris (1987). Earthquake deformation cycle on the San Andreas fault near Parkfield, California, J. Geophys. Res. 92,10,511 – 10,525.
Shakal, A., V. Graizer, M. Huang, R. Borcherdt, H. Haddadi, K. Lin, C. Stephens, and P. Roffers (2005). Preliminary analysis of strong- motion recordings from the 28 September 2004 Parkfield, California earthquake, Seism. Res. Lett. 76,27 –39.
Shakal, A., H. Haddadi, V. Graizer, K. Lin, and M. Huang
(2006a). Some key features of the strong-motion data from the
M 6.0 Parkfield, California, earthquake of 28 September 2004,
Bull. Seism. Soc. Am.96
, no. 4B,S90
–S118.
Shakal, A. F., H. R. Haddadi, and M. J. Huang (2006b).
Note on the very high-acceleration Fault Zone 16 record from the 2004 Parkfield
earthquake, Bull. Seism. Soc. Am.96
, no. 4B,S119
–S142.
Shcherbakov, R., D. L. Turcotte, and J. B. Rundle
(2006). Scaling properties of the Parkfield aftershock sequence,
Bull. Seism. Soc. Am.96
, no. 4B,S376
–S384.
Shimazaki, K., and T. Nakata (1980). Time-predictable recurrence model for large earthquakes, Geophys. Res. Lett. 7,279 –282.[Web of Science][GeoRef]
Sieh, K. E. (1978a). Slip along the San Andreas fault
associated with the great 1857 earthquake, Bull. Seism. Soc.
Am. 68,1421
–1448.
Sieh, K. E. (1978b). Central California foreshocks of
the great 1857 earthquake, Bull. Seism. Soc. Am.68
,1731
–1749.
Simpson, R. W, M. Barall, J. Langbein, J. R. Murray, and M. J. Rymer
(2006). San Andreas fault geometry in the Parkfield, California,
region, Bull. Seism. Soc. Am.96
, no. 4B,S28
–S37.
Simpson, R. W., S. S. Schulz, L. D. Dietz, and R. O. Burford (1988). The response of creeping parts of the San Andreas fault to earthquakes on nearby faults: two examples, Pure Appl. Geophys. 126,665 –685.[CrossRef]
Sims, J. D. (1990). Geologic map of the San Andreas fault in the Parkfield 7.5-minute quadrangle, Monterey and Fresno Counties, California, U.S. Geol. Surv. Misc. Field Stud. Map MF 2115, scale 1:24,000.
Steacy, S., J. Gomberg, and M. Cocco (2005). Introduction to special section: stress transfer, earthquake triggering, and time-dependent seismic hazard, J. Geophys. Res.110 , doi10.1029/2005JB003692 .[CrossRef]
Stein, R. S. (1999). The role of stress transfer in earthquake occurrence, Nature402 ,605 –609.[CrossRef][GeoRef]
Thayer, M. R. (2006). Structural geology of the San Andreas fault zone at Middle Mountain, near Parkfield, central California, M.S. Thesis, Arizona State University, Tempe, 140 pp.
Thayer, M. R., J R. Arrowsmith, J. J. Young, A. K. Fayon, and M. J. Rymer (2004). Geologic structure of Middle Mountain within the San Andreas fault zone near Parkfield, California, EOS Trans. Am. Geophys. Union 85, no. 47,1335 .
Thurber, C., H. Zhang, F. Waldhauser, J. Hardebeck, A. Michael, and D. Eberhart-Phillips
(2006). Three-dimensional compressional wavespeed model, earthquake
relocations, and focal mechanisms for the Parkfield, California, region,
Bull. Seism. Soc. Am.96
, no. 4B,S38
– S49.
Titus, S. J., C. DeMets, and B. Tikoff (2006).
Thirty-five-year creep rates for the creeping segment of the San Andreas fault
and the effects of the 2004 Parkfield earthquake: constraints from alignment
arrays, continuous Global Positioning System, and creepmeters, Bull.
Seism. Soc. Am. 96, no. 4B,S250
–S268.
Toda, S., and R. S. Stein (2002). Response of the San Andreas fault to the 1983 Coalinga–Nuñez earthquakes: an application of interaction- based probabilities for parkfield, J. Geophys. Res. 107, doi10.1029/ 2001JB000172 .
Toké, N. A., and J R. Arrowsmith (2006).
Reassessment of a slip budget along the Parkfield segment of the San Andreas
fault, Bull. Seism. Soc. Am.96
, no. 4B,S339
–S348.
Toké, N. A., J R. Arrowsmith, J. J. Young, and C. J. Crosby
(2006). Paleoseismic and postseismic observations of surface slip
along the Parkfield segment of the San Andreas fault, Bull. Seism.
Soc. Am. 96, no. 4B,S221
–S238.
Toppozada, T., and D. Branum (2006). San Andreas
M 
6 earthquakes within 40 km of the Priest Valley end zone of the
1857 faulting, Bull. Seism. Soc. Am.96
, no. 4B,S385
–S396.
Waldhauser, F., W. L. Ellsworth, D. P. Schaff, and A. Cole (2004). Streaks, multiplets, and holes: high-resolution spatio-temporal behavior of Parkfield seismicity, Geophys. Res. Lett. 31,L18608 , doi10.1029/ 2004GL020649 .[CrossRef]
Wang, G.-Q., G.-Q. Tang, C. R. Jackson, X.-Y. Zhou, and Q.-L. Lin
(2006). Strong ground motions observed at the UPSAR
during the 2003 San Simeon (M 6.5) and 2004 Parkfield (M 6.0),
California, earthquakes, Bull. Seism. Soc. Am.96
, no. 4B,S159
–S182.
Weldon, R., K. Scharer, T. Fumal, and G. Biasi (2004). Wrightwood and the earthquake cycle: what a long recurrence record tells us about how faults work, GSA Today14 , no. 9, doi10.1130/1052–5173 .
Xia, K., A. J. Rosakis, H. Kanamori, and J. R. Rice
(2005). Laboratory earthquake along inhomogeneous faults:
directionality and supershear, Science308
,681
–684, doi10.1126/science.1108193
.
Young, J. J., J R. Arrowsmith, L. Colini, L. B. Grant, and B. Gootee
(2002). 3D excavation and measurement of recent rupture history
along the Cholame segment of the San Andreas fault, Bull. Seism. Soc.
Am. 92,2670
–2688.
| ||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
