query: what causes earthquakes in the san andreas fault

pos: San Andreas Fault zone may have triggered most of the major quakes on the northern San Andreas within the past 3,000 years. The evidence also shows the rupture direction going from north to south in each of these time-correlated events. However the 1906 San Francisco earthquake seems to have been the exception to this correlation because the plate movement was moved mostly from south to north and it was not preceded by a major quake in the Cascadia zone. The San Andreas Fault has had some notable earthquakes in historic times: San Andreas Fault The San Andreas Fault is a continental transform fault

pos: San Andreas Fault zone may have triggered most of the major quakes on the northern San Andreas within the past 3,000 years. The evidence also shows the rupture direction going from north to south in each of these time-correlated events. However the 1906 San Francisco earthquake seems to have been the exception to this correlation because the plate movement was moved mostly from south to north and it was not preceded by a major quake in the Cascadia zone. The San Andreas Fault has had some notable earthquakes in historic times: San Andreas Fault The San Andreas Fault is a continental transform fault

neg: Parkfield, California in rocks, heat flow, microseismicity, and geomagnetism around Parkfield. The observations of the San Andreas fault in Parkfield are hoped to help scientists better understand the physics of earthquakes and faulting; information gathered from Parkfield may still be used someday to issue predictions for major earthquakes along the San Andreas fault and around the world. Since 1985, the United States Geological Survey has been working on a project known as "The Parkfield Experiment", a long-term research project on the San Andreas fault. "The experiment's purpose is to better understand the physics of earthquakes — what actually happens on the fault

neg: Olancha Earthquake Sequence (2009) long depression town of population 192. This composition of California gives it unique topography, inclusive of the highest and lowest points of the United States, Mount Whitney and Death Valley. The San Andreas Fault is a transform boundary, which lies between the North American Plate and the Pacific Plate and extends 1200 km. A transform boundary in the lithosphere means that two plates create a ‘fracture zone’ and rub against one another, causing stress and resulting in an earthquake. California is located above the San Andreas Fault, and causes the majority of Californian Earthquakes, inclusive of the Olancha Earthquake Series

neg: San Andreas Fault Andreas Fault runs in a northwestern direction from Parkfield to Hollister. While the southern section of the fault and the parts through Parkfield experience earthquakes, the rest of the central section of the fault exhibits a phenomenon called aseismic creep, where the fault slips continuously without causing earthquakes. The southern segment (also known as the Mojave segment) begins near Bombay Beach, California. Box Canyon, near the Salton Sea, contains upturned strata associated with that section of the fault. The fault then runs along the southern base of the San Bernardino Mountains, crosses through the Cajon Pass and continues northwest along

neg: San Andreas Fault Observatory at Depth San Andreas Fault Observatory at Depth The San Andreas Fault Observatory at Depth (SAFOD) is a research project begun in 2002 aimed at collecting geological data about the San Andreas Fault for the purpose of predicting and analyzing future earthquakes. The site consists of a pilot hole and a main hole. Located near the town of Parkfield, California, the project has installed geophone sensors and GPS clocks in a borehole that cuts directly through the fault. This data, along with samples collected during drilling, could shed new light on geochemical and mechanical properties around the fault zone. SAFOD is part

neg: San Andreas Fault along the San Andreas Fault. A different USGS study in 2008 tried to assess the physical, social and economic consequences of a major earthquake in southern California. That study predicted that a magnitude 7.8 earthquake along the southern San Andreas Fault could cause about 1,800 deaths and $213 billion in damage. A 2008 paper, studying past earthquakes along the Pacific coastal zone, found a correlation in time between seismic events on the northern San Andreas Fault and the southern part of the Cascadia subduction zone (which stretches from Vancouver Island to northern California). Scientists believe quakes on the Cascadia subduction

neg: San Jacinto Mountains side is one of the most abrupt in North America, going from sea level to 10,000 feet in a few miles. The height and steepness of the range points out that the San Jacinto fault and San Andreas fault are very active and very capable of producing major earthquakes (well in excess of magnitude 7). The last massive quake struck the southern segment of the San Andreas-San Jacinto fault complex more than 200 years ago making another major earthquake likely but not currently possible to predict. Rock slides from the range are possible during major earthquakes in the future, as

neg: Imperial Fault Zone Andreas and the San Jacinto fault zones. However, studies covering the last few hundred years show that the slip rate is insufficient to account for the total slip from the San Andreas system. The surface trace is well-located based on mapped surface offsets from historic events. The Imperial Fault Zone has a history of earthquakes of moderate magnitude, including several doublet earthquakes. Imperial Fault Zone The Imperial Fault Zone is a system of geological faults located in Imperial County in the Southern California region, and adjacent Baja California state in Mexico. It cuts across the border between the United States

neg: San Andreas Fault Observatory at Depth of Earthscope, an Earth science program using geological and geophysical techniques to explore the structure of the North American continent and to understand the origin of earthquakes and volcanoes. Earthscope is funded by the National Science Foundation in conjunction with the U.S. Geological Survey and NASA. Data collected at SAFOD are available from The Northern California Earthquake Data Center at U.C. Berkeley and at the IRIS DMC. San Andreas Fault Observatory at Depth The San Andreas Fault Observatory at Depth (SAFOD) is a research project begun in 2002 aimed at collecting geological data about the San Andreas Fault for the

neg: 1969 Santa Rosa earthquakes the northern San Francisco Bay Area since the 1906 San Francisco earthquake. The current tectonics of northern California are mainly controlled by the San Andreas Fault system, the zone of dextral strike-slip faulting that accommodates displacement between the North American Plate and the Pacific Plate along this transform boundary. In addition to the San Andreas Fault itself there are numerous other sub-parallel dextral strike-slip faults that take up some of the plate boundary motion distributed through a zone more than 100 km wide. The 1969 earthquakes and most of their aftershocks occurred along the Healdsburg Fault, which lies between the

neg: Calaveras Fault plate is sliding northwestward along a transform boundary, the San Andreas Fault, toward the subduction zone. At the same time, the North American Plate is moving southwestward, but relatively southeast along the fault. 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. The Calaveras Fault shares the same relative motions of the San Andreas. A number of magnitude 6 earthquakes have been recorded on the fault throughout recorded history, the largest of which was a magnitude

neg: Visalia, California the western edge of the Sierra Nevada Foothills. Visalia is subject to earthquakes due to its proximity to the Pacific Ring of Fire. The geologic instability produces numerous fault lines both above and below ground, which altogether cause approximately 10,000 earthquakes every year. One of the major fault lines is the San Andreas Fault. No major earthquakes have hit the Visalia area. Most quakes are of low intensity and are not felt. The San Joaquin Valley and metropolitan areas are also at risk from blind thrust earthquakes. Parts of the city are also vulnerable to floods. Visalia has a cold

neg: 1838 San Andreas earthquake 1838 San Andreas earthquake The 1838 San Andreas earthquake is believed to be a rupture along the northern part of the San Andreas Fault in June 1838. It affected approximately 100 km (62 miles) of the fault, from the San Francisco Peninsula to the Santa Cruz Mountains. It was a strong earthquake, with an estimated moment magnitude of 6.8 to 7.2, making it one of the largest known earthquakes in California. The region was lightly populated at the time, although structural damage was reported in San Francisco, Oakland, and Monterey. It is unknown whether there were fatalities. Based on geological

neg: San Andreas Fault Following recorded seismic events in 1857, 1881, 1901, 1922, 1934, and 1966, scientists predicted that another earthquake should occur in Parkfield in 1993. It eventually occurred in 2004. Due to the frequency of predictable activity, Parkfield has become one of the most important areas in the world for large earthquake research. In 2004, work began just north of Parkfield on the San Andreas Fault Observatory at Depth (SAFOD). The goal of SAFOD is to drill a hole nearly into the Earth's crust and into the San Andreas Fault. An array of sensors will be installed to record earthquakes that happen

neg: Carrizo Plain about feet in an even larger earthquake. Two other older creek beds lie northwest along the San Andreas Fault. The first creek bed was created around 13,000 years ago when climate change formed the creek on a large active alluvial fan. The second bed was created about 11,000 years ago. The creek has been carefully studied by geologists to find a correlation between the offset and historical events, such as earthquakes, that have occurred along the San Andreas Fault. Although Wallace Creek is not the only creek that has been offset by the San Andreas Fault, it is the most

neg: Hayward Fault Zone 1906. Many seismologists believe that the 1906 San Francisco earthquake, which occurred on the San Andreas fault, reduced the stress on many faults in the Bay Area including the Hayward fault, creating an "earthquake shadow": a quiescent period following a major earthquake. Since the 1906 San Andreas event there have been no moderately strong earthquakes on the Hayward fault as were seen before that earthquake. It also appears likely that this quiet period in the earthquake shadow is ending, as projected by the rate of plate motion and the stress state of other faults in the region. The 1868 earthquake

neg: 1948 Desert Hot Springs earthquake earthquakes to determine the location of active faults. By 1948, seismologist Charles Richter had determined that areas where small earthquakes were occurring did not necessarily mean that a stronger shock would take place at the same location in the future. The San Gorgonio Pass is one of the largest irregularities of the San Andreas Fault system, where it branches into a group of discontinuous faults. The convoluted nature of the fault strands makes estimating the source characteristics of future events in that area challenging. Simultaneous rupture of multiple fault strands can produce exceptionally complex earthquakes, like the 1992 Landers earthquake,

neg: San Francisco capped with a tall cross built in 1934. Dominating this area is Sutro Tower, a large red and white radio and television transmission tower. The nearby San Andreas and Hayward Faults are responsible for much earthquake activity, although neither physically passes through the city itself. The San Andreas Fault caused the earthquakes in 1906 and 1989. Minor earthquakes occur on a regular basis. The threat of major earthquakes plays a large role in the city's infrastructure development. The city constructed an auxiliary water supply system and has repeatedly upgraded its building codes, requiring retrofits for older buildings and higher engineering

neg: San Andreas Fault section of the fault, i.e. the region around Los Angeles, because massive earthquakes have occurred relatively recently on the central (1857) and northern (1906) segments of the fault, while the southern section has not seen any similar rupture for at least 300 years. According to this study, a massive earthquake on that southern section of the San Andreas fault would result in major damage to the Palm Springs-Indio metropolitan area and other cities in San Bernardino, Riverside and Imperial counties in California, and Mexicali Municipality in Baja California. It would be strongly felt (and potentially cause significant damage) throughout much

neg: Hayward Fault Zone Hayward Fault Zone The Hayward Fault Zone is a geologic fault zone capable of generating destructive earthquakes. This fault is about 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. The Hayward Fault is parallel to the San Andreas Fault, which lies offshore and through the San Francisco Peninsula. To the east of the Hayward lies the Calaveras Fault. In 2007 the Hayward Fault was discovered to merge

neg: Earthquake weather plates is the San Andreas Fault. The San Andreas Fault is more than 800 miles long and extends to depths of at least 10 miles. Many other smaller faults like the Hayward (San Francisco Bay Area) and the San Jacinto (Southern California) join with the San Andreas to form the San Andreas Fault Zone. The Pacific Plate grinds northwestward past the North American Plate at a rate of about two inches per year. It has been proposed by W. J. Humphreys that "earthquake weather" is not of geological causes, but merely a psychological manifestation. Humphreys argued that "the general state

neg: San Jacinto Fault Zone seismologists, including Keiiti Aki and C. Allin Cornell, and was organized by the Southern California Earthquake Center for the USGS and the California Office of Emergency Services. The 1995 paper was the third in a series of reports that was set in motion following the 1992 Landers earthquake in southern California with the intention of updating the data and the approach for calculating the probabilities for large earthquakes along the southern San Andreas and San Jacinto Fault zones. Both these fault zones were grouped together as having adequate paleoseismic data to assign conditional probabilities for future damaging earthquakes. The original

neg: Salton City, California mere miles from major, destructive fault lines, such as the Imperial Fault, The San Andreas Fault Line, and the San Jacinto Fault Zone. The Superstition Faults also pose a major risk to the area, as well as The Brawley Seismic Zone, which produces frequent, yet mostly, non-damaging, earthquake swarms. At certain times, this area can experience dozens of felt earthquakes in a time period lasting from one day to over one week. Most of the earthquakes are minor to moderate and pose no hazard due to strict seismic codes, however, this area is notorious for Earthquake Swarms, and other major

neg: Parkfield, California and in the surrounding region before, during and after an earthquake." In 2004, work began just north of Parkfield on the San Andreas Fault Observatory at Depth (SAFOD). The goal of SAFOD is to drill a hole nearly 2.5 miles (4 kilometers) into the Earth's crust, across the San Andreas Fault. The specific target of the probe was a patch of fault known to generate sequences of repeating microearthquakes of around magnitude 1.0. The drilling was completed in the midyear of 2005, and an array of sensors was installed to capture and record earthquakes that happen near this area. It

neg: Parkfield earthquake Parkfield earthquake Parkfield earthquake is a name given to various large earthquakes that occurred in the vicinity of the town of Parkfield, California, United States. The San Andreas fault runs through this town, and six successive magnitude 6 earthquakes occurred on the fault at unusually regular intervals, between 12 and 32 years apart (with an average of every 22 years), between 1857 and 1966. The most recent significant earthquake to occur here happened on September 28, 2004. Earthquakes may occur regularly here because the location is about midway on a fault segment between a "locked" segment to the south (last

neg: Calaveras Fault Calaveras Fault 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. It is believed to link with the Hayward fault, as well as the West Napa Fault, north of the Carquinez Strait. It passes through or near the cities of Alamo, Danville, San Ramon, Dublin,

neg: San Andreas (film) 2015, received mixed reviews from critics and grossed $474 million worldwide. Caltech seismologist Dr. Lawrence Hayes and his colleague Dr. Kim Park are at Hoover Dam doing research for a new earthquake predicting model when a nearby and previously unknown fault ruptures. A 7.1 magnitude earthquake is triggered as a result, collapsing the dam; Park is killed during the collapse, shortly after rescuing a child. Following the disaster, Hayes discovers that the entire San Andreas Fault is shifting and will soon cause a series of major earthquakes, potentially destroying cities along the fault line. Ray Gaines, a Los Angeles Fire

neg: Los Angeles metropolitan area about 40 miles north east of Downtown Los Angeles. The closest towns and cities to Los Angeles which contain the San Andreas Fault are Gorman and Palmdale, California. Historically, major earthquakes have occurred along the fault, large enough to cause fatalities and millions of dollars in damages. A major earthquake hasn't happened in the southern section of the San Andreas Fault in over 150 years and geologist have determined a 50% probability of a 7.0 earthquake, registered on the moment magnitude scale within the years 2010 to 2040. Some geologists say that this probably is over speculated. There is currently

neg: 1838 San Andreas earthquake was a fault rupture that extended from San Francisco to San Juan Bautista. Since the South Francisco Bay is at the center of three plate boundary fault zones, many occurrences of earthquakes of magnitude <7 were recorded. The intensity of the earthquake had magnitude 7 ½ and extended to the Hayward fault. There is evidence of the fault rupture extending to Monterey because the aftershocks reached San Juan Bautista and Oakland. The rupture extending to San Francisco to San Juan Bautista had a length totaling ∼ 140 km and indicating an M ∼ 7:4 earthquake. It also caused two large

neg: Xianshuihe fault system the Sichuan-Yunnan block. The Xianshuihe fault system comprises several distinct segments, with an overall length of about 350 km. The main segments are the Ganzi (or Ganzi-Yushu), the Xianshuihe, the Anninghe-Zemuhe, and the Xiaojiang faults. Movements on this fault system have been responsible for many large historical earthquakes, with more than 20 events of magnitude greater than 6.5 since 1700. Some of these earthquakes have formed linked sequences, with each event being triggered by the previous one due to stress changes. Like the San Andreas Fault in California, the Xianshuihe exhibits a behavior called Aseismic creep. The Xianshuihe fault creeps

neg: Earthquake it in fault ruptures. Rocks hotter than about 300 degrees Celsius flow in response to stress; they do not rupture in earthquakes. The maximum observed lengths of ruptures and mapped faults (which may break in a single rupture) are approximately 1000 km. Examples are the earthquakes in Chile, 1960; Alaska, 1957; Sumatra, 2004, all in subduction zones. The longest earthquake ruptures on strike-slip faults, like the San Andreas Fault (1857, 1906), the North Anatolian Fault in Turkey (1939) and the Denali Fault in Alaska (2002), are about half to one third as long as the lengths along subducting plate margins,

neg: San Jose, California and California City). San Jose lies between the San Andreas Fault, the source of the 1989 Loma Prieta earthquake, and the Calaveras Fault. San Jose is shaken by moderate earthquakes on average one or two times a year. These quakes originate just east of the city on the creeping section of the Calaveras Fault, which is a major source of earthquake activity in Northern California. On April 14, 1984, at 1:15 pm local time, a 6.2 magnitude earthquake struck the Calaveras Fault near San Jose's Mount Hamilton. The most serious earthquake, in 1906, damaged many buildings in San Jose as

neg: Ring of Fire world's 25 largest volcanic eruptions of the last 11,700 years occurred at volcanoes in the Ring of Fire. The famous and very active San Andreas Fault zone of California is a transform fault which offsets a portion of the East Pacific Rise under the southwestern United States and Mexico; the motion of the fault generates numerous small earthquakes, at multiple times a day, most of which are too small to be felt. The active Queen Charlotte Fault on the west coast of the Haida Gwaii, British Columbia, has generated three large earthquakes during the 20th century: a magnitude 7 event

neg: Lakeport, California the west. These faults have been responsible for moderate to major earthquakes in the past. The maximum creditable earthquake magnitudes are 8.25 for the San Andreas fault and 6.75 for the Healdsburg fault. There is a potentially active rupture zone (defined as a fault that has been active during quaternary time – the last 2,000,000 years) existing immediately east of the City limits running parallel and adjacent to the shoreline of Clear Lake. Within the past 200 years, no major potentially damaging earthquakes have occurred along any faults within Lake County, including the Big Valley fault adjacent to the eastern

neg: 1838 San Andreas earthquake 1838 and the inception of 1776 Mission San Francisco Dolores, there had been no reported evidence of earthquakes. The post-1600 earthquake ruptures along several faults were depicted by records of the infrastructure in missions damaged, which were historically significant for evaluating evidence of earthquakes in the San Francisco Bay Area. The previous stress fractures were inferred in 1650-1770, while the M <7 was between 1776 and 1836. The speculation of the 1836 earthquake occurring at the North Hayward area were small shocks. The eruption of the Hayward fault in 1868 derived from the stress concentrated in the Hayward fault during

neg: Calaveras Fault more likely to fail in the next few decades than previously thought. Calaveras Fault 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. It is believed to link with the Hayward fault, as well as the West Napa Fault, north of the Carquinez Strait. It

neg: 1940 El Centro earthquake the Elsinore Fault Zone/Laguna Salada Fault to the western side of the trough and the Imperial Fault to the east. The Imperial Fault is linked to the San Andreas Fault through the Brawley Seismic Zone, which is a spreading center beneath the southern end of the Salton Sea. With the San Jacinto Fault Zone to the west, the Elsinore fault to the south-southwest, and the Imperial fault centered directly under the Imperial Valley, the area frequently encounters seismic activity, including moderate and damaging earthquakes. Other events in 1852, 1892, 1915, 1942, 1979, and 1987 have impacted the region in varying

neg: Megafault North America, ending at the San Andreas Fault. Any further instability will cause massive earthquakes and tsunamis, devastating Los Angeles, San Francisco and other cities all around the Pacific Ocean, leading to the deaths of millions. Dr. Lane and Boomer chase just behind the expanding crack in the Earth's crust, developing a plan to stop the next quake. They decide to use a satellite orbiting above the continent which can trigger earthquakes. They fire it off when they reach the Grand Canyon, thinking that when the new fault hits the canyon it will be forced to turn south into the

neg: San Andreas Fault "subducted", creating a new relative motion and a new style of deformation along the plate boundaries. These geological features are what are chiefly seen along San Andreas Fault. It also includes a possible driver for the deformation of the Basin and Range, separation of the Baja California Peninsula, and rotation of the Transverse Range. The main southern section of the San Andreas Fault proper has only existed for about 5 million years. The first known incarnation of the southern part of the fault was Clemens Well-Fenner-San Francisquito fault zone around 22–13 Ma. This system added the San Gabriel Fault as

neg: Paleoseismology absolute terms, if there is dateable carbon, or human artifacts. Many notable discoveries have been made using the techniques of paleoseismology. For example, there is a common misconception that having many smaller earthquakes can somehow 'relieve' a major fault such as the San Andreas, and reduce the chance of a major earthquake. It is now known (using paleoseismology) that nearly all the movement of the fault takes place with extremely large earthquakes. All of these seismic events (with a moment magnitude of over 8), leave some sort of trace in the sedimentation record. Another famous example involves the megathrust earthquakes

neg: Lake Cahuilla fault tectonic system. Volcanic activity and earthquakes occur as a consequence to this tectonic configuration. The San Andreas Fault runs roughly parallel to the northeastern margin of Lake Cahuilla, where it moved at a rate of over the last 45,000–50,000 years. Earthquakes are documented in sediments from Lake Cahuilla, but this southern segment has not ruptured in historical time. Tectonic extension occurs at the points where the fault forms stepovers, although the extensional structures are still relatively immature. The Cahuilla Basin, also known as the Salton Sink, is part of the trough that is occupied by the Gulf of California.

neg: Hayward Fault Zone the San Andreas. The complete fault zone, including the Rodgers Creek fault, is divided by seismologists into three segments – Rodgers Creek, Northern Hayward, and Southern Hayward. It is expected that these segments may fail singly or in adjacent pairs, creating earthquakes of varying magnitude. 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. The various ABAG maps shown below represent some of the more likely possible combinations. While there are indications that a substantial earthquake

neg: Raised beach be found north of Santa Cruz, near Davenport, California, where terraces probably have been raised by repeated slip earthquakes on the San Andreas Fault. Hans Jenny (pedologist) famously researched the pygmy forests of the Mendocino and Sonoma county marine terraces. The marine terrace's "ecological staircase" of Salt Point State Park is also bound by the San Andreas Fault. Along the coasts of South America marine terraces are present, where the highest ones are situated where plate margins lie above subducted oceanic ridges and the highest and most rapid rates of uplift occur. At Cape Laundi, Sumba Island, Indonesia an ancient

neg: Parkfield earthquake portion of the fault and at the southern end of the rapidly periodic segment. It is believed that this earthquake was preceded by a magnitude 6.0 foreshock that was centered at Parkfield. Parkfield earthquake Parkfield earthquake is a name given to various large earthquakes that occurred in the vicinity of the town of Parkfield, California, United States. The San Andreas fault runs through this town, and six successive magnitude 6 earthquakes occurred on the fault at unusually regular intervals, between 12 and 32 years apart (with an average of every 22 years), between 1857 and 1966. The most recent significant

neg: 1952 Kern County earthquake been responsible for minor earthquakes, but they are considered not as significant as the Kern Canyon, Owens Valley, and San Andreas Faults. The 1952 earthquakes were the first to be observed well within Kern County lines. Other strong, but remote events were previously felt in the area, but they were distant enough to cause only occasional destructive effects. The county is bounded on the western side by the Temblor Range which is adjacent to the southern San Andreas Fault. Other large events have affected the area as well, like the January 1857 Fort Tejon earthquake that severely affected Fort Tejon

neg: Earthquake forecasting than a meter to around 10 meters (for an M 8 quake), the demonstrated existence of large strike-slip displacements of hundreds of miles shows the existence of a long running earthquake cycle. The most studied earthquake faults (such as the Nankai megathrust, the Wasatch fault, and the San Andreas fault) appear to have distinct segments. The "characteristic earthquake" model postulates that earthquakes are generally constrained within these segments. As the lengths and other properties of the segments are fixed, earthquakes that rupture the entire fault should have similar characteristics. These include the maximum magnitude (which is limited by the length

neg: San Jacinto Fault Zone interval for a series of large earthquakes starting in 1899 (including the 5.9 1937 Terwilliger Valley earthquake) was 18, 5, 14, 5, 12, 14, and 19 years, yet there has not been a strong earthquake for years (since the 1987 Superstition Hills and Elmore Ranch sequence). The San Jacinto Fault Zone and the San Andreas Fault (SAF) accommodate up to 80% of the slip rate between the North American and Pacific plates. The extreme southern portion of the SAF has experienced two moderate events in historical times, while the SJFZ is one of California's most active fault zones and has

neg: 1857 Fort Tejon earthquake Angeles Aqueduct and California Aqueduct, two of the principal water transfer infrastructure systems supplying Greater Los Angeles, both cross the San Andreas fault within the main damage zone of the Fort Tejon earthquake, in the Tehachapi and Sierra Pelona Mountains. 1857 Fort Tejon earthquake The 1857 Fort Tejon earthquake occurred at about 8:20 am (Pacific time) on January 9 in central and Southern California. One of the largest recorded earthquakes in the United States, with an estimated moment magnitude of 7.9, it ruptured the southern part of the San Andreas Fault for a length of about 225 miles (350 kilometers),

neg: 1857 Fort Tejon earthquake Valley Block of the North American Plate at about per year. The displacement rate along the various sections that ruptured is per year along the Parkfield, Cholame, Carrizo and Big Bend sections and and per year along the Mojave north and Mojave south sections. Paleoseismic studies have found evidence for many prehistoric earthquakes in the last 3,000 years on this part of the San Andreas Fault. The earthquake ruptured a substantial portion of the southern San Andreas fault, but not the entire length. Thomas H. Jordan, director of the Southern California Earthquake Center, stated that the slip likely stopped in

neg: Joshua Tree National Park forces along the San Andreas Fault system compressed and lifted the crust material that formed these ranges. The San Andreas Fault itself passes southwest of the park, but related parallel faults including the Dillon, Blue Cut, and Pinto, run through the park, and movements along them have caused earthquakes. The easternmost range in the park, the Coxcomb Mountains, runs generally north–south and is part of the Basin and Range Province. Nine established campgrounds exist in the park, two of which (Black Rock Campground and Cottonwood Campground) provide water and flush toilets. A fee is charged per night for each camping

neg: 1952 Kern County earthquake and a reconnaissance report was recognized for its coverage of the event, and how it set a standard for those types of engineering or scientific papers. Repercussions of the sequence of earthquakes were still being felt in the heavily damaged downtown area of Bakersfield well into the 1990s as city leaders attempted to improve safety of the surviving unreinforced masonry buildings. At Lebec, California, just south of the epicenter of the July mainshock, the San Andreas Fault comes together with the Garlock Fault, which is positioned at the northern border of the Mojave Desert. The San Andreas has been responsible

neg: San Diego–Tijuana by the Biodiversity Research Center of the Californias of the San Diego Natural History Museum. The land on which San Diego–Tijuana sits is due west of a major transform fault. The transform fault, known as the San Andreas Fault was created during the Cenozoic Era by the movements of the Pacific Plate and North American Plate. The region experiences earthquakes and felt the shocks of the 2009 Gulf of California earthquake and 2010 Baja California earthquake. The main mountain ranges of the Peninsular Ranges ridging eastern San Diego–Tijuana are the Palomar Mountains, Laguna Mountains, Sierra de Juárez, and the peaks

neg: 1992 Cape Mendocino earthquakes (west of present-day Baja California) when the Pacific-Farallon spreading center initially approached the subduction zone off the coast of western North America. Simultaneously, the Rivera Triple Junction shifted to the southeast to its current position at 23° N. Once the Pacific Plate and North American Plate connected the boundary became that of a transform fault (San Andreas) due to the northwestward motion of the Pacific Plate relative to the North American Plate. The San Andreas Fault continues to lengthen to the northwest and the southeast as the two triple junctions continue their transient motion. North of the Mendocino Triple Junction,

neg: 1979 Imperial Valley earthquake spreading center beneath the southern end of the Salton Sea. With the San Jacinto Fault Zone to the northwest, the Elsinore fault to the south-southwest, and the Imperial fault centered directly under the Imperial Valley, the area frequently encounters seismic activity, including moderate and damaging earthquakes. Other events in 1852, 1892, 1915, 1940, 1942, and 1987 have impacted the region. More small to moderate events of less than 6.0 (local magnitude) have occurred in this area than any other section of the San Andreas fault system. The earthquake was caused by rupture along parts of the Imperial Fault, the Brawley

neg: San Jacinto Fault Zone began with the 1899 San Jacinto earthquake and occurred at intermittent intervals culminating with the 1987 Superstition Hills and Elmore Ranch events. The 1857 rupture spanned a total of and terminated on the southeast end near the point where the San Jacinto Fault Zone branches away from the San Andreas Fault Zone at the Cajon Pass. In a paper published in the journal "Science", Christopher Sanders plotted the earthquakes of the SJFZ by time and location and found that a uniform pattern became apparent. Moving southeastward from the Cajon Pass, the large SJFZ events appear on a line with a

neg: 1906 San Francisco earthquake destroyed. The events are remembered as one of the worst and deadliest earthquakes in the history of the United States. The death toll remains the greatest loss of life from a natural disaster in California's history and high in the lists of American disasters. The San Andreas Fault is a continental transform fault that forms part of the tectonic boundary between the Pacific Plate and the North American Plate. The strike-slip fault is characterized by mainly lateral motion in a dextral sense, where the western (Pacific) plate moves northward relative to the eastern (North American) plate. This fault runs the

neg: San Jose Earthquakes Berg, but was criticized due to San Jose's proximity to the San Andreas Fault. The NASL folded after the 1984 season and the Earthquakes played in the Western Soccer League (WSL) from 1985–88, under the ownership of Peter Bridgwater who sold the team in 1988. In 1994, Daniel Van Voorhis, former owner of the American Professional Soccer League's San Jose Hawks, successfully led a San Jose bidding group that was awarded one of Major League Soccer's inaugural teams. At that time, he handed over all existing Hawks player contracts, front-office resources and the rights to play in San Jose State

neg: Northern Cordilleran Volcanic Province and the terrains of which the volcanic province occupies have moved northwards. In the context of plate tectonics, strip-slip movement of the Tintina Fault is also related to strike-slip movement along the San Andreas Fault and other extensional or strike-slip fault systems of western North America. To the west, the Denali Fault is the source of minor earthquakes that extend along the length of the fault. In contrast to the Tintina Fault, strike-slip movement along the Denali Fault has offset at least of the surface. The fault separates mountains of the Insular Belt from mountains east of the fault. Tectonic

neg: Monta Vista Fault Monta Vista Fault The Monta Vista Fault is a potentially active fault, (a fault capable of generating destructive earthquakes) in Santa Clara County, California. It is a relatively short fault that runs between and generally parallel to the much longer San Andreas Fault and Hayward Fault Zones, trending northwest along the eastern foothills of the Santa Cruz Mountains in the Coast Range Geomorphic Province. The most recent activity has been estimated to have been approximately 700,000 years ago. It has a slip rate of 0.4 mm/year. The fault runs through the campus of the Foothill College, meandering from under the

neg: Monta Vista Fault child-care center and fine arts building to alongside the campus center and the Carriage House. Monta Vista Fault The Monta Vista Fault is a potentially active fault, (a fault capable of generating destructive earthquakes) in Santa Clara County, California. It is a relatively short fault that runs between and generally parallel to the much longer San Andreas Fault and Hayward Fault Zones, trending northwest along the eastern foothills of the Santa Cruz Mountains in the Coast Range Geomorphic Province. The most recent activity has been estimated to have been approximately 700,000 years ago. It has a slip rate of 0.4

neg: Parkfield earthquake aftershocks continued for more than a week after the initial event, moving in a northwesterly progression. In early October, there was a cluster of small earthquakes near Paso Robles near a parallel fault to the west. These may be in response to the transfer of stress to these faults after the release of stress at Parkfield. Past earthquakes have also occurred to the east of Parkfield at about the same distance from the San Andreas fault near Coalinga and Avenal. In December 2004, seismologists at the University of California, Berkeley announced the discovery of subtle tremors near Cholame, a hamlet

neg: Malibu, California a tornado came ashore and struck a naval base's hangar, ripping off the roof. It was the first tornado to strike Malibu's shoreline in recorded history. Malibu is within of the San Andreas Fault, a fault over in length that can produce an earthquake over magnitude 8. Several faults are in the region, making the area prone to earthquakes. The Northridge earthquake and the 1971 Sylmar earthquake (magnitudes 6.7 and 6.6) shook the area. Smaller earthquakes happen more often. Malibu is a general law city governed with a five-member City Council including the mayor and mayor pro tem. The City

neg: San Jose Earthquakes (1974–88) created by general manager Dick Berg, but was criticized due to San Jose's proximity to the San Andreas Fault. Outdoor: Note: The team played as the Golden Bay Earthquakes in the 1983 and 1984 seasons. In the winter of 1975, the NASL ran a two-tiered, 16-team indoor tournament with four regional winners meeting in a "final-four" style championship. Not only did San Jose host their region at the Cow Palace, but the final four as well. The Quakes swept through the tournament unscathed, defeating the Tampa Bay Rowdies 8–5 in the final to the delight of their fans. San Jose

neg: Cascadia subduction zone On the Hyndman and Wang diagram (not shown, click on reference link below) the "locked" zone is storing up energy for an earthquake, and the "transition" zone, although somewhat plastic, could probably rupture. The Cascadia subduction zone runs from triple junctions at its north and south ends. To the north, just below Haida Gwaii, it intersects the Queen Charlotte Fault and the Explorer Ridge. To the south, just off of Cape Mendocino in California, it intersects the San Andreas Fault and the Mendocino Fracture Zone at the Mendocino Triple Junction. Megathrust earthquakes are the most powerful earthquakes known to occur,

neg: Porterville, California ready access to major transportation routes. Porterville is subject to earthquakes due to its location within the Pacific Ring of Fire. The geologic instability involves numerous faults, which cause many earthquakes every year, but most are of low intensity and are not felt. The primary plate boundary is the San Andreas Fault, which was the source of the 1857 Fort Tejon earthquake. Another major event that affected the Porterville area was the Kern County sequence of shocks that occurred on the White Wolf Fault during July and August 1952. Most parts of the city are also vulnerable to floods. The

neg: Puente Hills Fault occurrence is relatively rare compared to the San Andreas Fault, which is a transform fault. More specifically, geologists have determined that the fault has ruptured at least four times in the past 11,000 years. The magnitudes of such earthquakes are considered to have been 7.2 – 7.5 . The highest magnitude in that range would be about fifteen times stronger than the 1994 Northridge earthquake in terms of energy release. That event was the strongest in recorded history for the Los Angeles metropolitan area. The location of the fault directly below metropolitan Los Angeles leads it to be of great

neg: Laguna Salada Fault is a probable southern continuation of the Elsinore Fault Zone in Southern California. These faults are considered to be secondary cohorts of the San Andreas Fault, and as such share some of the strike-slip motion between the North American Plate and the Pacific Plate. Laguna Salada Fault The Laguna Salada Fault is a geological fault between the United States and Mexico. About long, it straddles the Imperial County-California–Baja California border. According to some seismologists the 1892 Laguna Salada earthquake ranks among the largest earthquakes in California and Baja California in historic times. It occurred on 23 February 1892, and was

neg: Morgan Hill, California fault zones. The nearest known active faults are the San Andreas Fault, approximately southwest, and the Calaveras Fault, approximately northeast. Both faults have produced major earthquakes in the past, and have estimated maximum credible Richter magnitudes of 8.3 and 7.3 respectively. The 1984 Morgan Hill earthquake registered at a 6.2 magnitude. Within Morgan Hill's area are a number of lakes and reservoirs, including Anderson Lake (eastern Morgan Hill), Uvas Reservoir (west), Chesbro Reservoir (west), and Coyote Lake (south). The Sargent-Berrocal Fault, a potentially active fault, lies away from the sites and has an estimated maximum credible Richter magnitude of 7.4.

neg: Missouri Bootheel National Weather Service reported that from 1980 to 2002, nine floods in the United States had total losses exceeding one billion dollars. In terms of monetary loss and effects on society, the Great Flood of 1993 was the worst. Earthquakes have long been frequent in the area. The New Madrid Fault Zone (pronounced ) is named for the city of New Madrid in the Bootheel. This fault zone is entirely hidden beneath the deep alluvial deposits of the Mississippi embayment. Unlike the San Andreas Fault in California, it is not visible anywhere. This fault zone was responsible for an extremely

neg: UCERF2 model (ERM) is produced, from which the time-dependent probability model (UCERF) is derived. (For more information see "Can earthquakes be predicted?" in the External links.) It should be noted that the concept of stress-renewal has been criticized, and may even be invalid, These are the six geologic faults in California with sufficient data to use a stress-renewal model for estimating the probability of an M ≥ 6.7 earthquake within the next 30 years. The Hayward fault zone and Rodgers Creek fault are treated as a single fault; the San Andreas fault is treated as two sections. A complete listing of

neg: 1992 Cape Mendocino earthquakes Sources 1992 Cape Mendocino earthquakes The 1992 Cape Mendocino earthquakes (or 1992 Petrolia earthquakes) occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino Triple Junction, a complex system of three major faults (including the Cascadia subduction zone, San Andreas Fault, and Mendocino Fracture Zone) that converge

neg: 1992 Cape Mendocino earthquakes 1992 Cape Mendocino earthquakes The 1992 Cape Mendocino earthquakes (or 1992 Petrolia earthquakes) occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino Triple Junction, a complex system of three major faults (including the Cascadia subduction zone, San Andreas Fault, and Mendocino Fracture Zone) that converge near

neg: Los Angeles are common in the Los Angeles area, although only the last is native. Los Angeles is subject to earthquakes because of its location on the Pacific Ring of Fire. The geologic instability has produced numerous faults, which cause approximately 10,000 earthquakes annually in Southern California, though most of them are too small to be felt. The strike-slip San Andreas Fault system is located at the boundary between the Pacific Plate and the North American Plate, and is vulnerable to the "big one", a potentially large and damaging event after the San Francisco earthquake in 1906. The Los Angeles basin and

neg: John Gribbin (1971). In 1968, Gribbin worked as one of Fred Hoyle's research students at the Institute of Theoretical Astronomy, and wrote a number of stories for "New Scientist" about the Institute's research and what were eventually discovered to be pulsars. In 1974, Gribbin, along with Stephen Plagemann, published a book titled "The Jupiter Effect", which predicted that the alignment of the planets in a quadrant on one side of the Sun on 10 March 1982 would cause gravitational effects that would trigger earthquakes in the San Andreas Fault, possibly wiping out Los Angeles and its suburbs. Gribbin distanced himself from "The

neg: San Andreas Lake San Andreas Lake San Andreas Lake is a reservoir adjacent to the San Francisco Peninsula cities of Millbrae and San Bruno in San Mateo County, California. It is situated directly on the San Andreas Fault, which is named after the valley it is in. After discovering San Francisco Bay from Sweeney Ridge on November 4, 1769, the Portolá expedition descended what Portolà called the "Cañada de San Francisco", now San Andreas Creek, to camp in the vicinity of today's San Andreas Lake. The next day they reached a "Laguna Grande" which today is covered by the Upper Crystal Springs Reservoir.

neg: Lake Cahuilla 1713. Less certain is the timing of events between 959 – 1015 and 1320 – 1489. Patterns of seismic activity detected by paleoseismology suggest that the filling of Lake Cahuilla might have triggered stress changes that caused earthquakes along the San Andreas Fault and other faults when they were already close to rupture. Such lake-induced seismicity is known from reservoirs and referred to as induced seismicity. Alternatively, earthquakes could have caused course changes in the Colorado River that then caused the lake to flood or to dry up; paleoseismology in Coachella is consistent with this hypothesis. Some earthquakes such as

neg: Earthquake California's San Andreas Fault someday, as depicted in the novels "Richter 10" (1996), "Goodbye California" (1977), "2012" (2009) and "San Andreas" (2015) among other works. Jacob M. Appel's widely anthologized short story, "A Comparative Seismology", features a con artist who convinces an elderly woman that an apocalyptic earthquake is imminent. Contemporary depictions of earthquakes in film are variable in the manner in which they reflect human psychological reactions to the actual trauma that can be caused to directly afflicted families and their loved ones. Disaster mental health response research emphasizes the need to be aware of the different roles of

neg: Aftershock sequence is deemed to have ended when the rate of seismicity drops back to a background level; i.e., no further decay in the number of events with time can be detected. Land movement around the New Madrid is reported to be no more than a year, in contrast to the San Andreas Fault which averages up to a year across California. Aftershocks on the San Andreas are now believed to top out at 10 years while earthquakes in New Madrid are considered aftershocks nearly 200 years after the 1812 New Madrid earthquake. Some scientists have tried to use foreshocks to

neg: Pull-apart basin activity along the fault. The Salton Trough is an active pull-apart located in a step-over between the dextral San Andreas Fault and the Imperial Fault. Displacement on the fault is approximately 6 cm/yr. The current transtensional state generates normal growth faults and some strike slip motion. The growth faults in the region strike N15E, have steep dips (~70 deg), and vertical displacements of 1–4 mm/yr. Eight large slip events have occurred on these faults with throw ranging from 0.2–1.0 meters. These produce earthquakes greater than magnitude six and are responsible for the majority of extension in the basin and consequently

neg: Denali National Park and Preserve rock sequence is the McKinley Intrusive Sequence, which includes Denali. The Cantwell Volcanics include basalt and rhyolite flows, as well as ash deposits. An example can be seen at Polychrome Pass in the park. Denali National Park and Preserve is located in an area of intense tectonic activity: the Pacific Plate is subducting under the North American plate, creating the Denali fault system, which is a right-lateral strike-slip fault over long. This is a part of the larger fault system which includes the famous San Andreas Fault of California. Over 600 earthquakes occur in the park each year, helping seismologists

neg: Submarine earthquake earthquakes; for example the Mariana Trench, Puerto Rico Trench, and the volcanic arc along the Great Sumatran fault. A transform-fault boundary, or simply a transform boundary is where two plates will slide past each other, and the irregular pattern of their edges may catch on each other. The lithosphere is neither added to from the asthenosphere nor is it destroyed as in convergent plate action. For example, along the San Andreas fault strike-slip fault zone, the Pacific Tectonic Plate has been moving along at about 5 cm/yr in a northwesterly direction, whereas the North American Plate is moving south-easterly. Rising

neg: Diamond Valley Lake sandy alluvium in the floor of the reservoir and the rock fill came from the bedrock highlands of the reservoir's south rim. Design and construction of the dams took into consideration the threat of earthquakes with the San Jacinto Fault Zone, located about underneath from the reservoir, and the San Andreas Fault, located about from the reservoir. The west dam rises to above the valley floor. It spans over a nearly flat alluvial valley floor between bedrock abutment ridges. About 65% of the dam's foundation area is founded on quartzite and phyllite bedrock. The remainder is founded on dense alluvium

neg: International Continental Scientific Drilling Program i.e. magma, hot fluids, groundwater and sediment, controls the concentration of metals and hydrocarbons as well as providing renewable geothermal energy resources. ICDP has accepted many proposals related to formation, potential hazard, and mitigation associated with fault boundaries, volcanoes, impact structures and plate margins. Topics include, but are not limited to, earthquakes generated on fault boundaries like San Andreas Fault and North Anatolian Fault Zone, geophysical and geochemical properties of different volcanic sources, impact basin evolution and effect on Earth’s environment and ecology, and tsunamis generation. The International Continental Scientific Drilling Program accepts proposals each year by Jan 15th from

neg: 1989 Loma Prieta earthquake for the northern San Andreas Fault segment, the San Francisco Peninsula segment, and a portion of that segment which was referred to as the southern Santa Cruz Mountains segment. The thirty year probability for one or more M7 earthquakes in the study area was given as 50%, but because of a lack of information and low confidence, a 30% probability was assigned to the Southern Santa Cruz Mountains segment. Two moderate shocks, referred to as the Lake Elsman earthquakes by the USGS, occurred in the Santa Cruz Mountains region in June 1988 and again in August 1989. Following each event,

neg: San Gabriel Fault only further west between Saugus and Castaic-Gorman. The San Gabriel Fault was once part of the San Andreas Fault, and is believed to be the former path of it. It is also believed that the northwestern end of this fault zone meets the current San Andreas Fault zone beneath the Frazier Mountain Thrust, near the juncture of the San Andreas with the Garlock Fault and Big Pine Fault. The San Gabriel Fault moves at a rate of between 1 and 5 millimeters a year, with an average slip of around 3 millimeters. San Gabriel Fault The San Gabriel Fault is

neg: Los Angeles metropolitan area off, the Pacific Plate had a general north west movement while the North American Plate had a general south east movement. This created a new fault zone when a weak point gave way between these two plates. This is the beginnings of the infamous San Andreas Fault. The San Andreas Fault is a right-lateral strike strip transverse fault. When this fault was just created, a volcano from the ancient subduction zone was situated about 3/4th on the Pacific Plate and 1/4th on the North American plate somewhere in what is today Central California. Nearly 55 million years later, this volcano

neg: Earthquake differences in stress drop during faulting, which contributes to differences in the radiated energy, regardless of fault dimensions. Where plate boundaries occur within the continental lithosphere, deformation is spread out over a much larger area than the plate boundary itself. In the case of the San Andreas fault continental transform, many earthquakes occur away from the plate boundary and are related to strains developed within the broader zone of deformation caused by major irregularities in the fault trace (e.g., the "Big bend" region). The Northridge earthquake was associated with movement on a blind thrust within such a zone. Another example

neg: Frame Lake and the southern of the two points of the western peninsula. Small diabase dykes run through various portions of the bedrock, with the largest forming the elevated area at the lake's southeast corner. Quartz intrusions are visible in some areas. Two local faults run across the south end of the lake. The stream from Robinson's Pond runs along the Pud Fault, which continues across the lakebed to McNiven Beach. At the south end is the larger Kam Fault, which when it was active had the same potential for earthquakes as the San Andreas Fault in the U.S. state of California.

neg: San Andreas Creek San Andreas Creek San Andrés Creek ("Spanish for": St. Andrew's Creek), now called San Andreas Creek, is a perennial stream that flows southeasterly along the San Andreas Fault from Sweeney Ridge in San Mateo County, California, providing the inflow to and outflow from San Andreas Reservoir, and then entering Lower Crystal Springs Reservoir, where it was a historic tributary to San Mateo Creek. San Mateo Creek then carries its waters over Crystal Springs Dam northeast to San Francisco Bay. After discovering San Francisco Bay from Sweeney Ridge on November 4, 1769, the Portolà expedition descended what Portolà called the "Cañada

neg: 1980 Eureka earthquake provided data by which an estimate of the peak ground acceleration could be made. Near Cape Mendocino, the Mendocino Triple Junction is an area of active seismicity where three tectonic plates come together. The Mendocino Fracture Zone (also known as the Mendocino Fault east of the Gorda Ridge) is a transform fault that separates the Pacific and Gorda Plates. To the south, the relative motion between the Pacific Plate and North American Plate is accommodated by the San Andreas Fault, and to the north, the Gorda Plate is converging with the North American Plate at the Cascadia Subduction Zone. Earthquakes

neg: Calaveras Fault Pleasanton, Sunol, Milpitas, San Jose, Gilroy, and Hollister. To the east of the Hayward-Rodgers Creek fault, the Calaveras fault extends , splaying from the San Andreas fault near Hollister and terminating at Danville at its northern end. 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. Between the San Andreas Fault and the Calaveras Fault lies the Hayward Fault, which diverges from the Calaveras Fault east of San Jose, California. To the east lies the Clayton-Marsh Creek-Greenville Fault. These four fault structures

neg: San Andreas Fault San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal). The fault divides into three segments, each with different characteristics and a different degree of earthquake risk. The slip rate along the fault ranges from /yr. The fault was identified in 1895 by Professor Andrew Lawson of UC Berkeley, who discovered the northern zone. It is often described as having been named after San Andreas Lake, a small body of water that

neg: San Jacinto Fault Zone event and another slipped as the smaller of the two shocks during the November 1987 sequence. The first shock (on what became known as the Elmore Ranch fault) measured 6.2 M and the shock 11.4 hours later on the SHF measured 6.6 M. ( & ) Notes Sources San Jacinto Fault Zone The San Jacinto Fault Zone (SJFZ) is a major strike-slip fault zone that runs through San Bernardino, Riverside, San Diego, and Imperial Counties in Southern California. The SJFZ is a component of the larger San Andreas transform system and is considered to be the most seismically active fault

neg: Geography of El Salvador ocean floor are forced down, they melt, and the molten material pours up through weaknesses in the surface rock, producing volcanoes and geysers. North of El Salvador, Mexico and most of Guatemala are riding on the westward-moving North American Plate that butts against the northern edge of the stationary Caribbean Plate in southern Guatemala. The grinding action of these two plates creates a fault (similar to the San Andreas fault in California) that runs the length of the valley of the Rio Motagua in Guatemala. Motion along this fault is the source of earthquakes in northernmost El Salvador. El Salvador

neg: Rohnert Park, California a number of creeks. Important creeks include the Laguna de Santa Rosa (which forms part of the border with the City of Cotati), Copeland Creek, Hinebaugh Creek, Crane Creek and Five Creek. All creeks within the city limits have been channelized. Spivock Creek, Coleman Creek, Wilfred Channel, and Labath Channel are artificial channels designed to convey runoff. The Rodgers Creek Fault is an active fault influencing earthquake activity in the Rohnert Park area. The city also experiences earthquakes from the San Andreas Fault. The city is organized into sections, designated by the letters A–H, "J", "K", "L", "M", "R", and

neg: Los Angeles Basin Peninsular Ranges, this basin experiences both compressional and strike slip tectonics. During the early Pliocene, also identified as the "Basin Disruption" phase, deformation and folding occurred as a result of fault movement and a slight rotation event. While movement along the San Andreas Fault is responsible for the placement of the basin, it is the Whittier and Newport–Inglewood faults that have dictated the seismic behavior within the basin. The Los Angeles basin is still active tectonically and the region continues to experience earthquakes as a result. Due to the number of faults and fault splays, seismic activity is not concentrated

neg: Transform fault up with San Andreas Fault to the North. Transform faults are not limited to oceanic crust and spreading centers; many of them are on continental margins. The best example is the San Andreas Fault on the Pacific coast of the United States. The San Andreas Fault links the East Pacific Rise off the West coast of Mexico (Gulf of California) to the Mendocino Triple Junction (Part of the Juan de Fuca plate) off the coast of the Northwestern United States, making it a ridge-to-transform-style fault. The formation of the San Andreas Fault system occurred fairly recently during the Oligocene Period

neg: Kerry Sieh Kerry Sieh Kerry E. Sieh is an American geologist and seismologist. Sieh's principal research interest is earthquake geology, which uses geological layers and landforms to understand the geometries of active faults, the earthquakes they generate, and the crustal structure their movements produce. His early work on the San Andreas fault led to the discovery of how often and how regularly it produces large earthquakes in southern California. Sieh received his undergraduate degree in geology from the University of California, Riverside in 1972 and his Ph.D. degree in geology from Stanford University in 1977. He was a professor of geology at

neg: Salton Sea from the Colorado River have been linked to earthquakes along the San Andreas Fault. Sonar and other instruments were used to map the Salton Sea's underwater faults during the study. During the period when the basin was filled by Lake Cahuilla, a much larger inland sea, earthquakes higher than magnitude 7 occurred roughly every 180 years, the last one occurring within decades of 1700. Computer models suggest the normal faults in the area are most vulnerable to deviatoric stress loading by filling in of water. Currently, a risk still exists for an earthquake of magnitude 7 to 8. Simulations also

neg: 2011 Oklahoma earthquake each other, but unlike the similar moving San Andreas Fault, the Wilzetta Fault is not located near the margins of any tectonic plates. From 1972 to 2008, between two and six earthquakes were recorded annually by the USGS, however 50 were recorded in 2009. The USGS and the Oklahoma Geological Survey are installing more seismometers to better monitor the increased activity. Aftershocks from the 5.6 quake, including some that can be felt, were expected to last for months. The Oklahoma Geological Survey reported in 2011 that a minor earthquake swarm which occurred in January 2011 could possibly have been due