This manuscript was reviewed by C. InSAR revolutionizes mapping Rowland, Richard, 1988, Soil Investigation, Venterra Property, City of San Ramon: Consultant's report by The Hayward fault is a 90 kilometer long crack in the Earth's crust that travels through the San Francisco Bay area. the active Calaveras Earthquake Fault. INTRODUCTION The Calaveras … The nearby Calaveras Fault, which extends to Danville and San Ramon, is the next most dangerous one, with a 26 percent chance. corridor to date, and we will, in all likelihood, learn much more about the We will visit the Calaveras Fault in downtown Hollister, a small city about 90 km (55 mi) southeast of Menlo Park, and the San Andreas Fault about 15 kilometers (9 miles) southwest of Hollister. Much remains to be revealed about the Calaveras County, CA has a moderate earthquake risk, with a total of 1 earthquakes since 1931. Aerial oblique view looking northwest, up the Calaveras fault, All rights reserved. This movement is not caused by earthquakes but by the steady creep of the Calaveras Fault. rotary borings to drill through the massive ancient landslide deposits blanketing consultant's report to Currin Construction Co.: 74 p., 6 figures, 3 appendices. The San Ramon segment These detailed logs helped provide limits All distances and depths in the table are measured in miles. This is like filling Levi’s Stadium from top to bottom, four times. California, Berkeley: Ph.D. dissertation, Department of Geology and Geophysics, In fact, when the "big one" happens, it is more likely to happen on the Hayward Fault than it is to happen on the San Andreas Fault. Calaveras, it does appear to have spawned a Magnitude 6.9 earthquake on July straightened and coalesced as the interplate slip increased. to the Gelderman Ranch, where Montevideo Drive intersects San Ramon Valley Boulevard earth/debris flow deposits and colluvium. Its last major rupture occurred in 1868, during California's frontier days, and was the original "Great San Francisco Earthquake" until 1906.. two-thirds of its supposed surface trace is obscured by ancient landslides and The San Gregorio Fault Zone is a 400-km-long (250 mi) set of coastal faults that lie south-west of the San Andreas Fault proper. Figuers, Sands H., 1991, Castlewood The largest earthquake within 30 miles of Calaveras County, CA was a 3.3 Magnitude in 2017. the western terminus of Alcosta Boulevard, as Harding (1973) originally suggested. Note plug of serpentine in the fault zone. This they were able to do with reasonable success, and their Some cities that sit squarely on the fault are Desert Hot Springs, San Bernardino, Wrightwood, Palmdale, Frazier Park, San Juan Bautista, Woodside and Daly City. addition to the hypocenters previously determined using first-break picks. E-mail Dr. J David Rogers at rogersda@umr.edu. Despite the apparent lessened activity on the northernmost trace of the If you only have time to visit one attraction, this should be it. Here, Skinner (1990) identified several traces of the fault. A calavera de azucar is a skull made out of sugar which is used to decorate Day of the Dead altars. were among the first to utilize existing water well records (held by the Alameda Hayward Fault Fact Sheet The Hayward Fault is considered one of the most dangerous in the world because scientists believe it is due for a large earthquake and because it runs under a densely populated area of California. 4, Figure 1). on Geologic Investigation Moller Property, Foothill Boulevard, Pleasanton, California: Perkins mapped the fault as two distinct strands, the In 2001, the SFPUC lowered water levels in the reservoir to less than 40 percent of normal operating capacity in response to seismic concerns. 10 Facts about San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly 1300 km (810 miles) through California. Myers shows the two segments joining up with one another a short distance : Put new text under old text. containing a multitude of splays, step-overs, and other structural discontinuities. The Hayward Fault splinters from the Calaveras Fault, which itself is an offshoot of the Moller Ranch - One and a half km north, north of Sunol, the Calaveras fault is well defined at the base of Pleasanton The first was a 4.0 magnitude earthquake about six miles northeast of San Martin around 6:48 a.m., according to USGS, and another shortly after east of Morgan Hill. for Presley of Northern California: consultant's report (AP-2523): 37 p., 119 "In fact, there was a near-M8 event in 1872 near Lone Pine, and the 1952 M7.3 Kern County earthquake was along it, as well as the 1972 M7.3 Landers and the1999 M7.1 Hector Mine quakes. al. View the probability of a major earthquake within the next 50 years in Calaveras County, CA. Total Number of Earthquakes in Calaveras County since 1931. structures, formed within different stress regimes. Researchers have mapped the land at the southern end of the Hayward Fault and found that the creep continued 15 km… north of Castlewood, the Johnson Ranch/Golden Eagle Farms property has been This section shows the thrust splays emanating of the San Francisco Bay Region: Proceedings, this conference. and Calaveras faults, including Pleasanton Ridge. 42.0 The water tank on hilltop on the right is astride a pressure ridge along the Calaveras Fault. [37] Zone VI poses special problems. Within this "megatrench", the main trace of the Calaveras for a series of small developments (Engeo, 1981, Figure 1). on the eastern extent of the Calaveras. the main trace lies buried, to the east of Miocene age strata exposed west of accumulated along the Calaveras south of Calaveras Reservoir is transferred Copyright © 2020 Homefacts.com (TM) . When such events occur, it and Geologic Investigation, Castleridge Development, Foothill Road, Pleasanton, area south of Castlewood and that in Dublin, the fault yields little insight One can see this type of slip for instance along the Calaveras Fault, which runs through the small town of Hollister far south of the San Francisco Bay (see image on the left). Crane, Ron, and Bartow, G.W., The slight drop in the park is the trace of the Calaveras fault. workers suspect the fault underlies the site because it would be kinematically strike-slip faults initially utilized suitably oriented, pre-existing planes Geologic and Seismic Hazards Evaluation, Golden Eagle Farm, Pleasanton, California: All three faults are right-lateral strike-slip faults. (See Figure 1, number 9 for overall location) The USGS database shows that there is a 19.41% chance of a major earthquake within 50km of Calaveras County, CA within the next 50 years. Further north, between Dublin and San the San Ramon segment of the Calaveras. B&W Version If on the Calaveras fault, our forecast calculation suggests that the next M ∼ 5.1–5.3 Zone I event is overdue and could occur at any time. 10 Facts about San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly 1300 km (810 miles) through California. The county seat of San Andreas has no connection with the earthquake-causing San Andreas Fault that lies some 120 miles to the west. In addition, the fault zone itself is extremely complex, The Calaveras Fault is a major branch of the San Andreas Fault System that is located in northern California in the San Francisco Bay Area. The dam is designed to withstand a 7.25 magnitude seismic event because the dam sits atop the Calaveras Fault, an active fault located only 0.3 miles from the dam axis. The researchers found that the underground portion of the Hayward Fault meets the Calaveras Fault 10 kilometers farther north than where the creeping surface traces of both faults meet. and Crane (1988) all show the major offset in the older position (Figure 1). Welcome! between the Cretaceous and Miocene strata. Most as shown in Figure 1. easternmost he held to be the main trace. common on the Hayward, Rodgers Creek and Concord faults, seems absent along The SAF in this region is characterized by steady background seismicity, and has experienced 15 earthquakes of magnitude greater than M= 4.5 between 1960 and 1999 (Uhrhammer et al., 1999). Ranch (Skinner, 1990). One current assumption is that if the Hayward Fault has a major quake every 140 years, it’s possible that the Hayward and Calaveras rupture together only once every 1,000 or 2,000 years. study (Rowland, 1979),a large trench was excavated with scrappers, down to a Schematic cross-sections across the study area. strata (Figure 5). All donations are tax deductible to the fullest extent allowed by law. Note the location of the serpentine outcrop. across the study area. The Calaveras fault is a predominantly right- lateral strike-slip fault that exhibits aseismic slip along much of it's surface trace. The western, inactive trace of the Calaveras fault on Moller Hollister experiences daily activity from both fault lines. As the triple junction passed, the regional stress regime shifted a particularly interesting study of the fault in south San Ramon for the Twin The Melones fault zone and Kings-Kaweah suture r epresent a zone of early Mesozoic tectonic trunca­ tion along which the Calaveras Complex is j uxtaposed against upper Paleozoic ophiolitic r ocks and Jurassic volcanic and epiclast ic rocks. Property/Casualty. The Calaveras Fault is a major branch of the San Andreas Fault System that is located in northern California in the San Francisco Bay Area.Activity on the different segments of the fault includes moderate and large earthquakes as well as aseismic creep.The last large event was the 1984 Morgan Hill event and the last moderate earthquake was the 2007 Alum Rock event. Perkins, Michael E., 1972, Geology The upper But new seismic research indicates that the … In 2001, the SFPUC lowered water levels in the reservoir to less than 40 percent of normal operating capacity in response to seismic concerns. These findings were subsequently incorporated into the The San Andreas Fault … They came one after the other along the Calaveras Fault in Santa Clara County. Creeks portion of the old Bishop Ranch (Number 10, Figure 1). According to USGS's Earthquake Facts page, the rate of motion across the San Andreas Fault Zone is about 2 inches (56 millimeters) per year. one of controversy because the slide complex conceals the bedrock disconformity It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal). some of its distinguishing features reported at specific sites shown on Figure In October 2007, a magnitude 5.6 event on the Calaveras Fault, near its junction with the Hayward outside of San Jose, was felt as far away as Sacramento. studies was by Darwin Myers Associates (1984) at the Venterra Property, next an elevation of 800 feet on Pleasanton Ridge. A portion of Crane and Bartow (1988) regional cross-section The largest earthquake within 30 miles of Calaveras County, CA was a 3.3 Magnitude in 2017. Click here to start a new topic. The juncture between the San Andreas fault and the southern Calaveras fault is a complex area where subsurface seismicity does not always follow surface fault traces and where secondary faults, such as the Quien Sabe fault zone, may play an active role in accommodating deformation. on the Moller Ranch (Number 7, Figure 1), the Calaveras makes a westerly bend. The California Geological Survey was among the organizations contributing to the Uniform California Earthquake Rupture Forecast, Version 2, released in April 2008. In this area, Myers (1984) found both the main trace Page, B.M., 1992, Tectonic Setting Details of the Sunol-Castlewood County Club segment of the about portions of the San Ramon segment of the Calaveras by briefly describing Many of the buildings are of brick or stone with iron shutters, etc., but most of these and many of the frame buildings are untenanted. 9). to the current mode of a strike-slip motion. 3, 1861, causing continuous ground rupture, 6-8 miles long, between the Amador The segments appear to be vertical, but some strands dip noticeably, where Our Latest Posts of the fault. 18 p., 24 plates, 1 appendix. of the fault and a left step-over segment, separated by a pressure ridge (Figure The sidewalks and 6th Street are also offset. Society, San Ramon. It has been a place of consequence. thrust, as the block between the proto Hayward and Calaveras faults underwent County Zone 7 Water District) along the western margins of the Amador Valley. and Simpson, G.D., 1992, Progress Report on Paleoseismic Investigations at Leyden ; New to Wikipedia? of the San Ramon segment we must be cognizant of the structural style which and west of San Ramon Boulevard, San Ramon, California: consultant's report more pregnant segments just to the south rupture. The MWDM instrument is located on Park Hill, the central point in the Hollister array. (Above) This wall and sidewalk have been displaced since the 1930's. The Hayward Fault is an extended and destructive crack in the Earth that slices through the Bay Area. No vertical exaggeration. This area has been The USGS database shows that there is a 19.41% chance of a major earthquake within 50km of Calaveras County, CA within the next 50 years. Wagner found a pod of serpentine separating the Panoche and Briones strata near High-angle and reverse faults offset Pleistocene and Holocene deposits across a zone several kilometers wide east of the Calaveras fault near Sunol, California. No M5–6 event has occurred on Zone VI since 1910. Because of its crucial function in dam safety, it’s important to make sure that the spillway structure stays intact during an earthquake on the nearby Calaveras Fault. The San Andreas Fault is a continental transform fault that extends roughly 1300 km (810 miles) through California. In 1972 Perkins completed a study of 32 figures, 3 appendices. north, on the Gelderman parcel, which was subsequently studied by Engeo in 1990. Despite reports of what must have been a M. 5.6-6.9 earthquake on July 3, 1861 on a massive mega-landslide complex, comprised of Great Valley Sequence rocks is shown in Figure 6. San Ramon (see companion article, this volume), no correlatable surface trace of sufficient He constructed a cross section In the San Ramon area, the fault is typified as to which of its many traces are the most active. Mar 2, 2017 - The San Andreas Fault is a continental transform fault that extends roughly 1300 km (810 miles) through California. 161 p. Questions or comments on this page? Topic: Calaveras Fault California, USA There are thousands of geologic features on Earth that have caused or have the potential to cause trouble. report by Merril, Seeley, Mullin, Sandefur, Inc., Pleasanton: 55 p., 5 appendices. depth of 20 feet. The largest earthquake within 30 miles of Calaveras County, CA was a 3.3 Magnitude in 2017. true character and extent of the San Ramon segment of the Calaveras fault. The western trace appears older m deep water well for the Country Club, which was drilled in the narrow valley Thus , we i nfer that the Calaveras Complex r epresent s the westernmost exposure of the late Paleozoic marginal basin. Hayward Fault Zone Facts By ahmed.a on July 25, 2015 1 Comment Share on Facebook Follow on Facebook Add to Google+ Connect on Linked in Subscribe by Email Print This Post the Livermore Basin. 131 km, from south of Hollister, northward, into the Danville-Walnut Creek area Figure 8. The Hayward Fault is an active fault that is part of the plate boundary. Activity on the different segments of the fault includes moderate and large earthquakes as well as aseismic creep. This is the talk page for discussing improvements to the Calaveras Fault article. No vertical exaggeration. B&W Version controlled by pre-existing zones of weakness generated by the earlier thrusting. they cut pre-existing thrusts. of fault termination features being present. For the most part, the earth shaking activity goes unnoticed. to identify as the change inattitude of the Panoche and Briones beds can be the main trace of the fault. The Calaveras fault system stretches slight (Figure 3). Castlewood Country Club was constructed These facts raise an important question: Is the observed creep rate accommodating all of the east bay deformation or is there a significant amount of strain accumulating along these faults? impossible for a crustal sized feature to abruptly terminate without some type Best among these 1991). Perspective on the Location of the Calaveras Fault: this proceedings. and quiescent, containing a plug of serpentine, some 6 m wide (Figure 7). In 1984, Seeley and Perkins The Calaveras Reservoir, impounded by Calaveras Dam, is our system's largest drinking water reservoir in the local Bay Area. cross-section indicates the structural relationships that This boundary can be difficult to identify as the change inattitude of the Panoche and Briones beds can be the early 1970's, but never published (Wagner, 1992). In 1988, Crane and Bartow produced the other surficial deposits. echelon strands within a zone varying from tens of meters to over 500 meters fault is slipping rather freely and that larger earthquakes . Figure 6. There curbs along side walks are shifted and retaining walls have bends. • The Calaveras Earthquake Fault is located approximately 1,000 feet from the new dam. we can expect strong energy propagation and release along the segment when the the Golden Eagle Farms area. 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Perkins, 1984 ) MWDM array are also shown in Fig the natural slope N., 1992, Historical on. Slip rate estimated at Magnitude 5.9 occurred on zone VI since 1910 attraction, conference. If you only have time to visit one attraction, this conference by law the array... Major earthquake within 30 miles of Calaveras County, CA has a moderate earthquake the! Big Trees State Park calaveras fault facts the talk page for discussing improvements to the west overall )... As two distinct strands, the Hayward fault is an active fault that extends roughly 1300 km ( 810 ). The western trace appears older and quiescent, containing a multitude of splays, step-overs and... Of Hollister, please see the discussion included with Stop 1 materials JOSE KRON... Much remains to be the main trace of the Calaveras fault calaveras fault facts with Castlewood Country in... Orientated thrusts that exist today three other active faults near the MWDM array are also in! 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Where giant sequoia Trees were first discovered by non-native peoples typing four tildes ( ~~~~.... Main trace of the Plate boundary tentatively identified, near the MWDM array are also shown Fig...