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Buried Rupture Earthquakes
In seismology, a buried rupture earthquake, or blind earthquake, is an earthquake which does not produce a visible offset in the ground along the fault (as opposed to a surface rupture earthquake, which does). When the fault in question is a thrust fault, the earthquake is known as a blind thrust earthquake. Ground motion Recorded ground motions of large surface-rupture earthquakes are weaker than the ground motions from buried rupture earthquakes. Depth The asperity for a buried rupture earthquakes is in area deeper than roughly . Examples are the Loma Prieta earthquake, Northridge earthquake, and the Noto Hanto earthquake. Tsunamis As compared to the seabed surface rupture case, uplifted water outside the fault plane in buried rupture earthquakes makes for large tsunami waves. See also * Aseismic creep In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaiser Permanente Building After Northridge Earthquake
Kaiser ( ; ) is the title historically used by German and Austrian emperors. In German, the title in principle applies to rulers anywhere in the world above the rank of king (). In English, the word ''kaiser'' is mainly applied to the emperors of the unified German Empire (1871–1918) and the emperors of the Austrian Empire (1804–1918). During the First World War, anti-German sentiment was at its zenith; the term ''kaiser''—especially as applied to Wilhelm II, German Emperor—thus gained considerable negative connotations in English-speaking countries. Especially in Central Europe, between northern Italy and southern Poland, between western Austria and western Ukraine and in Bavaria, Emperor Franz Joseph I is still associated with (the emperor) today. As a result of his long reign from 1848 to 1916 and the associated Golden Age before the First World War, this title often has still a very high historical respect in this geographical area. Etymology and language usage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loma Prieta Earthquake
On October 17, 1989, at 5:04 p.m. PST, the Loma Prieta earthquake occurred at the Central Coast of California. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately 10 mi (16 km) northeast of Santa Cruz on a section of the San Andreas Fault System and was named for the nearby Loma Prieta Peak in the Santa Cruz Mountains. With an magnitude of 6.9 and a maximum Modified Mercalli intensity of IX (''Violent''), the shock was responsible for 63 deaths and 3,757 injuries. The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap) until two moderate foreshocks occurred in June 1988 and again in August 1989. Damage was heavy in Santa Cruz County and less so to the south in Monterey County, but effects extended well to the north into the San Francisco Bay Area, both on the San Francisco Peninsula a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismology
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes (or generally, quakes) and the generation and propagation of elastic waves through planetary bodies. It also includes studies of the environmental effects of earthquakes such as tsunamis; other seismic sources such as volcanoes, plate tectonics, glaciers, rivers, oceanic microseisms, and the atmosphere; and artificial processes such as explosions. Paleoseismology is a related field that uses geology to infer information regarding past earthquakes. A recording of Earth's motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist who works in basic or applied seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buried Rupture Earthquakes
In seismology, a buried rupture earthquake, or blind earthquake, is an earthquake which does not produce a visible offset in the ground along the fault (as opposed to a surface rupture earthquake, which does). When the fault in question is a thrust fault, the earthquake is known as a blind thrust earthquake. Ground motion Recorded ground motions of large surface-rupture earthquakes are weaker than the ground motions from buried rupture earthquakes. Depth The asperity for a buried rupture earthquakes is in area deeper than roughly . Examples are the Loma Prieta earthquake, Northridge earthquake, and the Noto Hanto earthquake. Tsunamis As compared to the seabed surface rupture case, uplifted water outside the fault plane in buried rupture earthquakes makes for large tsunami waves. See also * Aseismic creep In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aseismic Creep
In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "after-slip" days to years after an earthquake. Notable examples of aseismic slip include faults in California (e.g. Calaveras Fault, Hayward Fault, and San Andreas Fault). Causes Aseismic creep accommodates far-field motions on localized zones of deformation at tectonic plate boundaries. The underlying causes of aseismic creep are primarily attributed to poor frictional strength of the fault, low normal stress acting on the fault in the shallow crust, and excessive pore-fluid pressures, which limit the viable amount of normal stress on a fault. The frictional reaction of geologic materials can explain the transition from seismic to aseismic deformation with depth. Friction along faults can cause sudden slips with associated stress drops (earthquakes), along with phases of no motion as stress recharges. Measur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami Waves
A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances) above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event. Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide. For this reason, it is often referred to as a tidal wave, although this usage is not favoured by the scientific community because it might give the false impression of a causal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Rupture
In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a Fault (geology), fault affects the Earth's surface. Surface rupture is opposed by buried rupture earthquakes, buried rupture, where there is no displacement at ground level. This is a major risk to any structure that is built across a fault zone that may be active fault, active, in addition to any risk from ground shaking. Surface rupture entails vertical or horizontal movement, on either side of a ruptured fault. Surface rupture can affect large areas of land. Lack of surface rupture Not every earthquake results in surface rupture, particularly for smaller and deeper earthquakes. In some cases, however, the lack of surface effects is because the fault that moved does not reach the surface. For example, the 1994 Northridge earthquake had a Moment magnitude scale, moment magnitude of 6.7, caused major damage in the Los Angeles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noto Hanto Earthquake
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Several earthquakes at or near Noto Peninsula, Japan, have been recorded: * 1892 Noto earthquake * 1993 Noto earthquake * 2007 Noto earthquake * 2023 Noto earthquake * 2024 Noto earthquake See also *1693 Sicily earthquake impacting the Italian city of Noto Noto (; ) is a city and in the Province of Syracuse, Sicily, Italy. It is southwest of the city of Syracuse at the foot of the Iblean Mountains. It lends its name to the surrounding area Val di Noto. In 2002 Noto and its church were decl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northridge Earthquake
The 1994 Northridge earthquake affected Greater Los Angeles, California, on January 17, 1994, at 04:30:55 PST. The epicenter of the moment 6.7 () blind thrust earthquake was beneath the San Fernando Valley. Lasting approximately 8 seconds and achieving the largest peak ground acceleration of over 1.7 ''g'', it was the largest earthquake in the area since 1971. Shaking was felt as far away as San Diego, Turlock, Las Vegas, Richfield, Phoenix, and Ensenada. Fifty-seven people died and more than 9,000 were injured. In addition, property damage was estimated to be $13–50 billion, making it among the costliest natural disasters in U.S. history. Geology The epicenter region of the earthquake was located in the San Fernando Valley, about northwest of downtown Los Angeles. The United States Geological Survey (USGS) placed the hypocenter's geographical coordinates at and at a depth of . Measuring 6.7, it was the largest earthquake recorded in the Los Angeles area since the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asperity (faults)
An asperity is an area on an active fault where there is increased friction, such that the fault may become locked, rather than continuously slipping as in aseismic creep. Earthquake rupture generally begins with the failure of an asperity, allowing the fault to move. See also * Asperity (materials science) * Asperity (geotechnical engineering) * Earthquake * Fault friction * Fault mechanics Fault mechanics is a field of study that investigates the behavior of geologic faults. Behind every good earthquake is some weak rock. Whether the rock remains weak becomes an important point in determining the potential for bigger earthquakes. ... References External links IRIS page on fault asperities with simple cartoon video of an asperity on an active faultIRIS page on "Modeling Asperities on a Strike-Slip Fault with Spaghetti" Seismology {{seismology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismology
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes (or generally, quakes) and the generation and propagation of elastic waves through planetary bodies. It also includes studies of the environmental effects of earthquakes such as tsunamis; other seismic sources such as volcanoes, plate tectonics, glaciers, rivers, oceanic microseisms, and the atmosphere; and artificial processes such as explosions. Paleoseismology is a related field that uses geology to infer information regarding past earthquakes. A recording of Earth's motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist who works in basic or applied seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Motion
Ground motion is the movement of the Earth’s surface from earthquakes or explosions. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the Earth and along its surface. This can be due to natural events, such as earthquakes and volcanic eruptions, or human activities, such as the detonation of nuclear weapons. There are two main types of seismic waves: body waves and surface waves. Body waves travel through the interior of the Earth, while surface waves travel along the Earth's surface. Ground motion is typically caused by surface waves, which are the most destructive type of seismic waves. Ground motion is measured using a seismometer A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
