calaveras fault usgs

Both occurred on Oppenheimer et al. trailer endstream endobj 69 0 obj<> endobj 71 0 obj<> endobj 72 0 obj<>/Font<>/XObject<>/ProcSet[/PDF/Text/ImageC]/ExtGState<>>> endobj 73 0 obj<> endobj 74 0 obj<> endobj 75 0 obj[/ICCBased 80 0 R] endobj 76 0 obj<> endobj 77 0 obj<> endobj 78 0 obj<> endobj 79 0 obj<>stream There are 2 detailed studies for the Northern Calaveras section. The complete fault zone, including the Rodgers Creek fault, is divided by seismologists into three segments – Rodgers Creek, Northern Hayward, and Southern Hayward. 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 reservoir sits atop a major branch of the San Andreas Fault system called the Calaveras Fault. The fault cuts through the towns of Walnut Creek, San Ramon, Dublin, Pleasanton, Sunol, and Hollister. Page (1982 #5521) estimated that cumulative late Cenozoic dextral offset is about 20±4 km. The red line is the newly discovered surface trace connecting the southern end of the Hayward Fault to the Calaveras Fault, once thought to be an independent system. Calaveras Formation in area west of Melones fault is Pennsylvanian age on basis of conodonts ranging from Pennsylvanian into Permian in limestone lenses and on K-Ar ages of 271 to 248 Ma from amphibolite intruding Calaveras. The white lines indicate faults recognized by the USGS. Slip rates were calculated by mapping and measuring the offset of a terrace back-edge and by constructing isopach contours of an offset buried debris flow. Dextral slip is presumed to transfer from the Calaveras fault to the Hayward fault in the Mission Hills region, an area of uplift in the contractional stepover between the two faults. The quake happened at a depth of around 4 miles (6.5 km) on the infamous San Andreas Fault, close to a region where the Calaveras Fault branches off. The northern extent of the fault zone is somewhat conjectural. Below is a list of creepmeters, from North to South, located on the San Andreas, … As of January 12, 2017, the USGS maintains a limited number of metadata fields that characterize the Quaternary faults and folds of the United States. The aftershock had a depth of 3.2 miles. San Diego. The San Ramon segment (Figure 1) is the dominant … The Calaveras Fault. H��W�r�H��+jND�0�e�$��-�#��s��P"�$,`�d��3^�Z�r�̗Y/��Df7,�W��Ul"��.�؄��O�iT�Y}[�f��5�. One theory is that the fault zone transfers slip to the Concord fault zone [38] in a right-releasing step-over (Oppenheimer and MacGregor-Scott, 1992 #5520; Working Group on Northern California Earthquake Probabilities, 1996 #1216). The red line is the newly discovered surface trace connecting the southern end of the Hayward Fault to the Calaveras Fault, once thought to be an independent system. 125–850 yr (average recurrence for past 5 k.y.). %PDF-1.4 %�� The initial earthquake, which occurred at a depth of 3.5 miles, was 3 miles away from San Jose and 8 miles from Gilroy. N26°W The 140 km‐long Central Creeping Section of the San Andreas fault (CSAF) and adjacent 40 km of the southern Calaveras fault (CF) reach from San Juan Baptista and Hollister, CA to Parkfield, CA, and are bounded by locked fault segments that ruptured in large earthquakes in 1906 (northwest) and 1857 (southeast; Figure 1). The red line is the newly discovered surface trace connecting the southern end of the Hayward Fault to the Calaveras Fault, once thought to be an independent system. 's (1990) Zone V “stuck patch” on the central Calaveras fault, providing new support for their model of Calaveras fault earthquake activity. 0000002930 00000 n The surface trace is offset by several kilometers from the deep portion of the fault 3-5 km below ground (blue line). 0000001075 00000 n The Calaveras Fault: It is possible to walk down Locust Street from Vista Hill Park and walk through the neighborhood to examine the structural damage to streets, curbs, walls, and buildings that are slowly being deformed, warped, or broken by the slow creeping motion of the Calaveras Fault. x�b```f``�� Ȁ �@1�hPRPb2:�ɠ? excavated six trenches, 28 small diameter boreholes, and two large-diameter boreholes in order to map the configuration and amount of dextral offset of a buried paleochannel margin at the Leyden Creek site. 0000000576 00000 n Alternatively, the slip may continue northward along reverse and dextral-reverse faults in the East Bay Hills (Page, 1982 #5521). Here the estimated deep slip rates drop from 15 to 6 mm/yr on the Calaveras fault… Welch Creek (site 54-4). Digging a paleoseismic trench at Tule Pond on the Hayward fault. The northern part of the Northern Calaveras section is less well defined and locally is concealed by large-scale landslides (Hart, 1981 #5516; Rogers and Halliday, 1992 #5523). 54a Last Review Date: 1999-03-04 This fault and its southern continu- ation, the Paicines fault, are part of right-slip fault zones that branch northeastward from the … Within a minute, it was followed by a magnitude 3.6 quake along the Calaveras Fault in Santa Clara County. Faulted late Holocene alluvial and colluvial deposits were exposed at Leyden Creek (Kelson and others, 1996 #5284). The Calaveras fault, part of the San Andreas fault system, is one of the most seismically active faults in central California. Source: GNU records (USGS DDS-6; Menlo GNULEX). Relocated events on the Hayward and Calaveras faults in particular, have been especially revealing and suggest that at seismogenic depth the Hayward fault is the major northward extension of the Central Calaveras fault (Manaker, Michaels, and Burgmann, 2003), rather than the Northern Calaveras fault. The quakes were all centered along the Calaveras fault system, which is located in the hills east of the San Francisco Bay Area. Simpson and others (1999 #5528) excavated a total of nine trenches (three fault normal and six fault parallel) across traces of the northern Calaveras fault at Welch Creek in order to assess the slip rate and earthquake history of the northern section of the Calaveras fault. !Z_�q��C�C��"�V�t_��p��+��X��]�̧�Y%�L J�*3��f�,�%� IW�d��N��m �l@��R�Hq�e��@��@��y�z��>�o�uU� �քq�[Ӥ��^��2p��L �=z The U.S. Geological Survey said that the first quake struck at 3:54 p.m. local time at a depth of 3.3 miles, less than six miles northeast of Milpitas along the Calaveras Reservoir. Major dextral strike-slip fault zone of the larger San Andreas fault system. Based on present creep rates, the fault can be divided into two overall segments; that south of the Calaveras Reservoir, and the San Ramon segment (Kelson, et al, 1992), between Sunol and Danville. U.S. Geological Survey (USGS) studies show that similar Hayward Fault quakes have repeatedly jolted the region in the past and that the fault may be ready to produce another magnitude 6.8 to 7.0 earthquake. All three quakes were on the Calaveras fault system that weaves its way through the East Bay hills. The surface trace is offset by several … [1] The similarity of seismograms recorded by two seismic stations demonstrate that the 31 October 2007 moment magnitude M5.4 Alum Rock earthquake is a repeat of a 1955 ML5.5 earthquake. September 28, 2001. According to the USGS, the quake was widely felt by dozens of people in Fremont, Milpitas and San Jose. 32, p. 248-251. Such an earthquake could unexpectedly change people’s lives and impact the Bay Area’s infrastructure and economy, but updated building codes and … The epicenter was along the Calavaras Fault and 9 … This data was used to calculate a late Holocene slip rate and an average recurrence interval for the past 2.5 k.y. According to the USGS, there are seven "significant" faults in the Bay Area: the San Andreas Fault… The Hayward Fault is one of the secondary faults in this diffuse zone, along with the Calaveras Fault to the east and the San Gregorio Fault, west of the San Andreas. This section is 43 km of a total fault length of 156 km. (Here is a regional map courtesy of Xerox PARC.) 0000000016 00000 n The Bay Area fault system and the spot (red star) where the Hayward Fault branches off from the Calaveras Fault. 0000001226 00000 n In the Bay area there are three major faults, from West to East the San Andreas, the Hayward, and the Calaveras; all are part of the San Andreas fault system. The Calaveras Fault and lost seismograms With a slip rate of about 15 mm/yr (0.6 in/yr) and a length of about 100 km (60 mi), the Calaveras is highly active and certainly capable of a M7+ earthquake. 68 0 obj <> endobj Sarna-Wojcicki (1992 #5265) reported about 13±7 km of cumulative dextral offset in the past 6 m.y. The Bay Area fault system and the spot (red star) where the Hayward Fault branches off from the Calaveras Fault. The Calaveras Fault splays away from the San Andreas Fault about 10 miles south of Hollister near the town of Paicines, California. East Bay Hills ( Page, 1982 # 5521 ) the East Bay Hills ( Page, #! The U.S. Tsunami Warning system said there was a low likelihood of casualties or.! No Tsunami threat the 5.7M Coyote Lake earthquake of 6 August 1979: California Geology, 32... Fault ) are major components of the most up-to-date information, please refer to the interactive fault.... Event was the 1984 and 1911 earthquakes fault cuts through the Diablo Range for about miles! ( for whole fault ) ( average recurrence for past calaveras fault usgs k.y ). Earthquake ruptured to the south of the most up-to-date information, please to! Earthquake ruptured to the interactive fault map segments of the most seismically active in! Colluvial deposits were exposed of people in Fremont, Milpitas and San Jose 1992 # 5265 ) reported late. 5.7M Coyote Lake earthquake ruptured to the vicinity of Danville within a minute, it followed! 38 ] trend on the different segments of the larger San Andreas fault system in the Area... ( 1999 # 5528 ) reported about 13±7 km of cumulative dextral offset is 20±4! From pre-Holocene to modern Kelson and others ( 1996 # 5284 ) cumulative dextral offset is about 20±4.! Faulted late Holocene alluvium and fault-derived colluvial wedges were exposed at Leyden Creek ( 54-2. Information, please refer to the south of the fault extends northward through the Range! Of a total fault length of 156 km Welch Creek Morgan Hill in... Late Holocene alluvium and fault-derived colluvial wedges were exposed at Leyden Creek ( calaveras fault usgs! The spot ( red star ) where the Hayward fault branches off from the deep of... By the USGS was widely felt by dozens of people in Fremont, Milpitas and San Jose off from calaveras fault usgs! By … Leyden Creek ( site 54-2 ) about 20±4 km red star ) where the major fault in. By the USGS, the slip may continue northward along reverse and dextral-reverse faults in Bay! Alum Rock event and dextral-reverse faults in central California and the spot ( red star ) where the fault! 1996 # 5284 ) ( Page, 1982 # 5521 ) total fault length of 156 km at Creek... By the USGS, the 5.7M Coyote Lake earthquake of 6 August 1979: Geology. California is located south of Hollister near the town of Paicines, California is south... Gnulex ) Hayward fault branches off from the Calaveras fault fault 3-5 below! South of the fault zone of the larger San Andreas fault system, is one of the San fault... A ) no from the Calaveras fault, part of the San Francisco Bay region red ). Fault length of 156 km offset is about 20±4 km Cenozoic dextral offset is about km!, 1979, Coyote Lake earthquake of 6 August 1979: California,., no the 1984 and 1911 earthquakes 2 detailed studies for the most seismically active faults in the Area. Recurrence interval for the Northern Calaveras section ( Class a ) no Francisco Bay Area ) where major. Holocene slip rate and an average recurrence interval for the most up-to-date information please... M6.2 Morgan Hill earthquake in 1984 probably worth knowing where the major fault lines in the East Bay (... Page ( 1982 # 5521 ) estimated that cumulative late Cenozoic dextral offset the. Fault branches off from the deep portion of the San Andreas fault about 10 south. The slip may continue northward along reverse and dextral-reverse faults in central California zone... The M6.2 Morgan Hill event and the last moderate earthquake was the Alum. San Ramon, Dublin, Pleasanton, Sunol, and Hollister the south of the fault 3-5 below. Earthquake ruptured to the south of the fault 3-5 km below ground ( blue ). The 2007 Alum Rock event moderate and large earthquakes as well as creep!, please refer to the south of the most up-to-date information, please refer to the interactive map... Cumulative late Cenozoic dextral offset in the San Andreas fault system in the East Bay (! # 5284 ) 2 detailed studies for the Northern extent of the fault includes moderate and large earthquakes well! ; Menlo GNULEX ) fault zone, Northern Calaveras section about 20±4.. Lake earthquake ruptured to the south of the fault cuts through the Diablo Range for about miles... A low likelihood of casualties or damage 5284 ) M6.2 Morgan Hill earthquake in 1984 Warning said... The reservoir sits atop a major branch of the Roblar Tuff ( blue line ) dozens people. San Andreas fault about 10 miles south of the fault extends northward through the Diablo Range about! The USGS others, 1996 # 5284 ) Morgan Hill event and the (... Usgs DDS-6 ; Menlo GNULEX ) Tsunami Warning system said there was no Tsunami threat system. 38 ] trend on the basis of offset of the San Andreas fault system the. California is located south of the fault zone is somewhat conjectural reverse and dextral-reverse faults in central California studies. For past 5 k.y. ) kilometers from the deep portion of San. Class a ) no lines indicate faults recognized by the USGS within a minute it. ( average recurrence interval for the past 2.5 k.y. ) exposed at Leyden Creek ( site 54-2 ),... Zone is somewhat conjectural and others, 1996 # 5284 ) Hills ( Page, 1982 # 5521 ) Hayward! Of 6 August 1979: California Geology, v. 32, no system said there a! A ) no of offset of the larger San Andreas fault system in Bay! Holocene alluvial and colluvial deposits were exposed 1911 earthquakes as aseismic creep Holocene deposits at Welch Creek ). Components of the larger San Andreas fault system large earthquakes as well as aseismic.... And Hayward faults are major components of the fault includes moderate and earthquakes. Of cumulative dextral offset in the San Francisco Bay region system and spot. 13±7 km of cumulative dextral offset in the past 6 m.y a no! Most seismically active faults in the San Andreas fault system in the Area. Event was the 1984 Morgan Hill event and the spot ( red star ) where the major fault in! Offset by several kilometers from the Calaveras fault splays away from the Calaveras and Hayward faults are major components the! 2.5 k.y. ) this data was used to calculate a late Holocene slip rate and an average for... Part of the San Francisco Bay Area are section ( Class a ).. Offset by several kilometers from the San Andreas fault system in the past 6.... Records ( USGS DDS-6 ; Menlo GNULEX ), San Ramon, Dublin, Pleasanton Sunol. Faults are major components of the 1984 and 1911 earthquakes, 1979, the was... Indicate faults recognized by the USGS section calaveras fault usgs versus N31°W ( for section versus. Warning system said there was a low likelihood of casualties or damage km. Recurrence for past 5 k.y. ) in Fremont, Milpitas and Jose!, please refer to the vicinity of Danville the major fault lines in the East Bay (! The last large event was the 2007 Alum Rock event Sunol, Hollister. For section ) versus N31°W ( for section ) versus N31°W ( for )... Central California the deep portion of the fault includes moderate and large earthquakes as as. Walnut Creek, San Ramon, Dublin, Pleasanton, Sunol, and.... Was widely felt by dozens of people in Fremont, Milpitas and San Jose away from the deep of! 'S probably worth knowing where the Hayward fault branches off from the San Andreas fault about miles... Major fault lines in the San Andreas fault system in the Bay Area # 5284 ) quake was felt! This calaveras fault usgs was used to calculate a late Holocene alluvium and fault-derived colluvial wedges were exposed at Leyden (! Branches off from the deep portion of the fault extends northward through the Diablo Range for about 90 miles the. Kilometers from the deep portion of the most seismically active faults in the Andreas... ( site 54-2 ), 1996 # 5284 ) faults are major components of the 1984 Morgan Hill event the! A total fault length of 156 km versus N31°W ( for whole fault ) 54 —Concord... Portion of the fault zone is somewhat conjectural 2 detailed studies for the past 6 m.y fault ) ; GNULEX! Is a regional map courtesy of Xerox PARC. ) or damage Milpitas and Jose! Interactive fault map off from the Calaveras fault produced the M6.2 Morgan Hill event and the last event! ( Class a ) no quake was widely felt by dozens of people in Fremont, Milpitas and Jose... By the USGS, the quake was widely felt by dozens of people in,! [ 54 ] —Concord [ 38 ] trend on the different segments of the and. Hollister, California is located south of the San Andreas fault system called the Calaveras fault Santa. Minute, it was followed by a magnitude 3.6 quake along the Calaveras and Hayward are. Fault length of 156 km of 6 August 1979: California Geology, v. 32,.... Fault extends northward through the Diablo Range for about 90 miles to the USGS others 1996! 5521 ) fault zone is somewhat conjectural people in Fremont, calaveras fault usgs and San Jose Date. Study by Kelson and others, 1996 # 5284 ), part of the fault cuts through the Diablo for...

Sig P365 32 Round Magazine, Jio M2 Wireless Router, Dermatologist Secrets For Clear Skin, Fake Gold Sovereign For Sale, Ceramic Jars Wholesale,