Subsequent seismic analysis indicated the possibility that the overfill could fail due to agitation, allowing the buoyant tube to float upward, misaligning the tracks and possibly overstressing the bolted connections. Some of the cities which the Calaveras Fault passes through or near are: Alamo, Danville, San Ramon, Dublin, Pleasanton, Sunol, Milpitas, San Jose, Gilroy, and Hollister. The magnitude of an earthquake, as indicated on a seismic scale, is roughly proportional to the length of the rupture, while the ground motion in the region surrounding the fault is highly dependent upon the local soil conditions, somewhat upon the distance and relationship to the progression of the fault rupture, and (as recently recognized in the 1989 Loma Prieta earthquake) reflected energy from deep discontinuities in the Earth's structure. As with portions of other faults, a large extent of the Hayward Fault trace is formed from a narrow complex zone of deformation which can span hundreds of feet in width. In addition to direct damage the effects on commerce due to damaged infrastructure would also be substantial. BSSA Special Issue on Martian Seismology and the InSight Mission to Mars Submission Deadline: 15 March 2021. Additionally, the soil itself can fail, turning into a liquid mud from the agitation, a mud unable to support buildings erected upon once-firm soil. [18] Earlier (January 2008) assessments suggest that the Hayward, Rodgers Creek, and Calaveras faults may be more likely to fail in the next few decades than previously thought.[2]. A November 9, 2004, construction accident on this pipeline system in Walnut Creek killed five people. The surface of the fault is creeping at less than 0.5 cm (0.2 in) per year in the regions of concern. The segments were sunk into a ditch dredged through bay mud and covered with rock fill, and then pumped free of water upon completion, making the resulting tube somewhat buoyant, but held in place with a rock overfill. The tube is composed of welded plate steel segments. This soft mud is expected to amplify earthquake shaking, and the mud supporting the heavy fill may liquefy, and so possibly cause major disruption of the highway due to failure by sinking of the highway and by differential movement of large sections. The work was the subject of several lawsuits from neighborhood and environmental groups, who were concerned about such extensive construction on top of a major fault. The Hayward fault in the San Francisco Bay area runs through a densely-populated area, so it has been studied quite a bit.The most recent major earthquake on this fault was approximately M6.9 and occurred in 1868. After the San Bruno pipeline explosion, which was unrelated to seismic activity, it took PG&E crews 95 minutes to stop the gas flow to both ends of that failed pipeline. Engineers and much of the public had long recognized that a strong earthquake centered close to the bridge on either the Hayward or San Andreas faults could cause a complete collapse of the eastern span. Faults allow the blocks to move relative to each other. Since the fault runs through heavily populated areas, more than 5 million would be affected directly. The Southern Loop was completed in 2002, while the seismic retrofitting of the Claremont tunnel was completed in February 2007.[25][26]. The Association of Bay Area Governments (ABAG) in concert with other government agencies has sponsored the analysis of local conditions and the preparation of maps indicative of the destructive potential of these earthquakes. Earthquake Safety Program Construction Updates, The Hayward Fault: Overdue for Destruction, Missing link between the Hayward and Rodgers Creek faults, The Rodgers Creek and Hayward Faults are revealed to be one fault, capable of a Magnitude=7.4 earthquake, The 2018 U.S. Geological Survey (USGS) HayWired Earthquake Scenario Fact Sheet 2018â3016, Rescue Lineament-Bear Mountains fault zone, https://en.wikipedia.org/w/index.php?title=Hayward_Fault_Zone&oldid=1000331516, Geology of Contra Costa County, California, Geology of Santa Clara County, California, Geography of Contra Costa County, California, Geography of Santa Clara County, California, Articles using abbreviated captions for seismic magnitude, Articles needing additional references from December 2008, All articles needing additional references, Creative Commons Attribution-ShareAlike License, Hayward Fault Zone earthquakes with a minimum. BART has installed and continues to enhance a network of seismic sensors (an earthquake warning system) to trigger a system halt in the event of a major event, this to include automated event progression analysis to determine the best action with regard to individual trains for maximum safety (a fault rip can take up to several tens of seconds to completely propagate from the epicenter to the more distant affected locations). Cities and Counties, or other local permitting authority, must regulate certain development "projects" within the zones. Service Contacts: Tech Support (gis@hayward-ca.gov) 510.583.4851; Owner Mailing Address Correction Form; Other Address Corrections (gis@hayward-ca.gov) Land Use and Zoning (PlanningDivision@hayward-ca.gov) 510.583.4200; All other data questions and corrections. Most faults produce repeated displacements over geologic The designed slip margin has been reduced by half due to unforeseen settlement of the tube structure. [23] As seen in other worldwide pipeline ruptures, even an instantaneous stop of pumping would take several minutes to significantly lower pipeline pressure after a break, and would likely result in the release of significant amounts of flammable liquid fuels. The State Geologist is required to delineate the various "seismic hazard zones." It was long believed that there was no connection between the Hayward Fault and the Calaveras, but geological studies[10] (particularly the examination of very small and deep earthquakes) suggest that the two may be connected. Such sensor networks and warning devices have a potential to reduce the hazards from falling objects and furnishings provided that the people notified are well trained in appropriate responses (similar to the Cold War's "duck and cover" training of schoolchildren). [1] It runs east of the San Andreas, diverging from it in the vicinity of Hollister, California, and is responsible for the formation of the Calaveras Valley there. The Hayward Fault is parallel to the San Andreas Fault, which lies offshore and through the San Francisco Peninsula. A simultaneous rupture of the connected Hayward-Rodgers Creek Fault â about 118 mi (190 km) long from just north of Healdsburg down to Alum Rock in San Jose â could result in a major earthquake of magnitude 7.4 that "would cause extensive damage and loss of life with global economic impact". Extensive upgrades over a recent eighteen-month interval have addressed the life safety issues,[28] including replacement of the football players' facilities, and an extensive seismic retrofit of those sections not subject to fault shearing. These four fault structures are some of the major faults in California at the latitude of San Francisco. This potential problem has been addressed by vibratory compaction of the overfill covering the tube. [9], The Calaveras Fault is continuous from the Sunol area south to Hollister. An earthquake may cause minor landsliding on some slopes of the freeway, and the plastic movement of the fill would likely disrupt the pavement if the movement here of the surface displacement is substantial, possibly presenting a hazard to motorists and shutting down the highway for a while. Earthquakes are shown as circles sized by magnitude (red, < 1 hour; blue, < 1 day, yellow, < 1 week). In 2028, it will have been 160 years since the 1868 event. The minor Concord Fault lies to the east of the Calaveras Fault, and small earthquakes occur in the gap between faults, mostly in the vicinity of Alamo, California, relieving stresses generated by the displacement between the two faults. Fault creep since 1923 offset the original walls at the north and south ends 13 inches (33 cm). [20], In 2012, USGS scientists said the fault is due for another magnitude 6.8 to 7.0 earthquake, with the California Geological Survey concurring, stating they believe there is a 31 percent chance of a magnitude-6.7 earthquake or greater along the Rodgers Creek-Hayward Fault in the next 30 years. It is becoming widely understood that professional fire fighting, police, and medical services will be overwhelmed by a major event and that neighbors will have to assist each other as best they can. Severe effects were seen in both Oakland and northern San Francisco from the 1989 Loma Prieta earthquake, even though this event was not extremely large and was centered a significant distance away in the Santa Cruz Mountains. Additionally, EBMUD created a second route to bring water to these west-of-the-hills customers through the Southern Loop Bypass near Castro Valley. The Hayward Fault Zone is a geologic fault zone capable of generating destructive earthquakes. The current estimates of the probability of a major earthquake on any of the numerous regional faults range up to 70 percent within the thirty-year period 2000â2029. The Hayward Fault Zone is a geologic fault zone capable of generating destructive earthquakes.This fault is about 74 mi (119 km) long, situated mainly along the western base of the hills on the east side of San Francisco Bay.It runs through densely populated areas, including Richmond, El Cerrito, Berkeley, Oakland, San Leandro, Castro Valley, Hayward, Union City, Fremont, and San Jose. Only a portion of the structural deficiencies in the larger area have been addressed, and the surface motion effects of a large event are likely to be far more severe than seen in the Loma Prieta event. Extreme southern regions of the fault are creeping more quickly, perhaps sufficiently to prevent fault rupture there, but mostly the creep is insufficient to relieve the accumulating forces upon most of the fault and so will not prevent a large earthquake. [6][7] An alternate prior hypothesis suggested that the Hayward Fault and Rodgers Creek Fault were probably connected by a series of en echelon fault strands beneath San Pablo Bay. Parallel to the Eastshore Freeway and inland only two blocks is a four-track railroad route used for general freight traffic, including that generated by the Port of Oakland (Union Pacific and BNSF railroads) and by Amtrak passenger traffic to the Pacific Northwest and eastward through Reno and Salt Lake City. However, the University has undertaken an extensive retrofitting project over the past decade to systematically retrofit all academic buildings on Campus to withstand a significant earthquake. Combined with the historic record, the last five major events were in 1315, 1470, 1630, 1725, and 1868,[16] which have intervals of about 140 years (note that 2018 is 150 years from the major 1868 event). (See the Virtual tour â Google Earth Flyover below.). In its northern extent, the Hayward Fault lies directly beneath the portion of Highway 13 (the Warren Freeway) that is south of its intersection with Highway 24 and north of its terminal connection with Interstate 580 (the MacArthur Freeway). Local surveys of recently completed work have exposed deficient workmanship in a number of cases involving household retrofits. [14] Recent renovations of the Meek Mansion have revealed that with the 1868 earthquake still fresh in minds of residents of the time, some unusual diagonal bracing was built into the original construction. The area affected by an earthquake is also dependent upon the density and uniformity of the soils surrounding the fault. (More modern construction for these conditions employs linked and "floating" â in mud â lightweight concrete and plastic foam box structures to support a road.) "The Hayward Fault: America's Most Dangerous? Due to the extensive use of point of sale scanners and registers in supermarkets this could also impact the ability of stores to sell essential items such as groceries and to preserve frozen food items, as well as terminating cable TV and most internet access. This also came back to bite the team at the end of games. It runs east of the San Andreas, diverging from it in the vicinity of Hollister, California, and is responsible for the formation of the Calaveras Valley there. Click or tap on a circle to view more details about an earthquake, such as location, date/time, magnitude, and links to more information about the quake. The Bay Area | CHP - Golden Gate Division The San Francisco Bay Area is a unique and busy metropolitan area that brings many challenges to both the motoring public and the CHP officers who patrol it. [11][12] In fact, the 1868 event became known as the "Great San Francisco earthquake" until the larger tremor in 1906. A severe earthquake is more likely to disable the offshore causeway portions of Interstate Highway 80 (the Eastshore Freeway), since it is built on fill placed in the 1930s atop mudflats whose upper layers were deposited in the 19th century as a result of extensive hydraulic gold mining in the distant Sierra Nevada mountain foothills. Aviation fuels are piped from these same refineries to the Oakland Airport. The westward component of the North American Plate's motion results in some compressive force along the San Andreas and its associated faults such as the Calaveras Fault, thus helping lift the Coast Ranges. As that portion includes the so-called Silicon Valley, the potential economic disruption due to destruction of works in progress and the dismantling of microelectronics fabrication plants could have an economic effect extending worldwide. Significant features were noted and marked. This region is also covered with dense low-rise urban development, most of which was built soon after the 1906 San Francisco earthquake, and long before even moderately earthquake resistant construction practices had been developed in the late 1920s. It is also being subducted far to the northwest into the Aleutian Trench. Potentially dangerous landslide areas are also marked, showing great areas beyond the fault that could be rendered uninhabitable by a major event. Faults may range in length from a few millimeters to thousands of kilometers. The 1989 Loma Prieta earthquake caused a failure of a single section of the upper deck of the eastern span of the San FranciscoâOakland Bay Bridge, which closed the bridge for 30 days. Creep effects may be seen also in older structures crossing the fault, some of which have been fitted with expansion joints to accommodate this slow motion. Moreover, they have a 51% chance of a Mâ¥7 (threshold to be considered a "major" quake), a 20% chance of a Mâ¥7.5 and a 4% chance of a Mâ¥8 (a "great" quake) when all the mapped faults in the region are taken in to account.[18]. Although it has been known for some time that the Calaveras and Hayward faults merge in the South Bay region, recent geological studies[5] suggest that the Calaveras and Hayward faults may be even more closely connected horizontally deep beneath the surface, angling toward each other with depth until they become a single fault. The transbay tube terminates at an under-bay slip joint near the Embarcadero Station in San Francisco. The complete fault zone, including the Rodgers Creek fault, is divided by seismologists into three segments â Rodgers Creek, Northern Hayward, and Southern Hayward. The transform boundary defined by the San Andreas Fault is not perfectly straight, and the stresses between the Pacific and North American Plates are diffused over a wide region of the West, extending as far as the eastern side of the Sierra Nevada Mountains. (This potential is not shown in the shake intensity maps shown below.). Assessments in January 2008[6] suggest that the northern Calaveras fault (the portion between Sunol and Danville) may be more likely to fail in the next few decades than previously thought. Shortly before her marriage to her childhood sweetheart, David Tredman, he dies and Lillian takes her first drink of many down the road of becoming an alcoholic. Much work remains to be done in the region and progress is being hampered by budget constraints imposed by trickle down federal-state-regional deficits, design and construction delays due to state and local political bickering over design, and unexpectedly high steel and cement costs due to the extensive construction work being done in China. A release on a major segment can substantially increase the likelihood of an earthquake on an adjacent fault segment, increasing the likelihood of two major regional earthquakes within a period of a few months. All are right lateral-moving strike-slip faults. [24], East Bay Municipal Utility District (EBMUD) supplies water to 800,000 East Bay customers who live west of the Berkeley Hills. The compressive pressure is manifest in a significant thrust fault nearby on the western slope of the mountain, the Mount Diablo Thrust Fault,[3] the most active of its kind in the region and which is also capable of producing significant local earthquakes affecting the Alamo-Danville area. At the lower elevations near the bay the soil is mostly water saturated mud and sand, placed in the early 20th century as fill in marsh areas. Additional stabilization includes the driving of large pilings and the connection of additional restraints. Some of the cities in the eastern bay shore and south bay region near this fault include Richmond, El Cerrito, Berkeley, Albany, Emeryville, Kensington, Oakland, Piedmont, San Leandro, San Lorenzo, Castro Valley, Hayward, Union City, Fremont, Newark, Milpitas, Niles, and portions of San Jose. State Highway 24, connecting Oakland to Orinda, Lafayette, and Walnut Creek through the Caldecott Tunnel, is composed of extensive earth fill at the location where the fault is crossed. With Susan Hayward, Richard Conte, Eddie Albert, Jo Van Fleet. In detail, the fault is a complex zone of crushed and broken rock from a few hundred feet to a mile wide. The Google Earth website, in cooperation with the United States Geological Survey, has prepared a virtual helicopter tour of the fault, with much additional information available through the tour. USGS ShakeMaps showing intensity patterns for the 1984 Morgan Hill (left) and 2007 Alum Rock events, "Characterization of the SFBR Earthquake Sources", http://gsa.confex.com/gsa/2005CD/finalprogram/abstract_85559.htm, https://www.pbs.org/newshour/indepth_coverage/science/1906quake/map6.html, "Historic Earthquakes: Calaveras fault, California". Temperature plays a critical role in defining the seismogenic zone, the area of the crust where earthquakes most commonly occur; however, thermal controls on fault ruptures are rarely observed directly. This is to be corrected at great expense â first estimated at $142 million but expected to cost far more â probably the largest single cost item in the list of BART seismic retrofits. The two faults in the San Francisco Bay Area most likely to have a damaging earthquake are the Hayward-Rodgers Creek fault system (31%) and the San Andreas Fault (21%). This in turn can make fuel supplies for vehicles and emergency generators unavailable locally and impact both domestic water, industrial water, sewage plants, and drainage pumping. Prior to the 2014 South Napa earthquake, it was the most powerful quake to hit the Bay Area since the Loma Prieta earthquake of 1989, and the largest on the Calaveras Fault since 1984. Cellphone and most landline telephone service, while theoretically survivable for a short time on battery and emergency power, could instead suffer immediate disruption from ground shaking effects. This soil tends to amplify the effects of an earthquake and so producing significantly greater ground motion. Affected areas are likely to be without electrical power for an extensive period. [4] The most recent of these was a magnitude 6.2 earthquake near Morgan Hill in 1984. In October 2016, scientists found definitive evidence that the Rodgers Creek Fault and the Hayward Fault are linked together under San Pablo Bay. Many structures near the bay shore on either side would probably be severely affected by either a major Hayward Fault rupture or a nearby San Andreas Fault rupture.