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Peak Ground Velocity
In seismology, strong ground motion is the strong earthquake shaking that occurs close to (less than about 50 km from) a causative fault. The strength of the shaking involved in strong ground motion usually overwhelms a seismometer, forcing the use of accelerographs (or strong ground motion accelerometers) for recording. The science of strong ground motion also deals with the variations of fault rupture, both in total displacement, energy released, and rupture velocity. As seismic instruments (and accelerometers in particular) become more common, it becomes necessary to correlate expected damage with instrument-readings. The old Modified Mercalli intensity scale (MM), a relic of the pre-instrument days, remains useful in the sense that each intensity-level provides an observable difference in seismic damage. After many years of trying every possible manipulation of accelerometer-time histories, it turns out that the extremely simple peak ground velocity (PGV) provides t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ShakeMap For 2001 M6
ShakeMap is a product of the U.S. Geological Survey (USGS) to map the shaking of earthquakes. According to the USGS, "ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. These maps are used by federal, state, and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information, as well as for preparedness exercises and disaster planning." The system's development was led largely by USGS seismologist David J. Wald with others. ShakeMap's goal is to "go beyond magnitude and epicenter" to depict the variations in the distribution of shaking intensity. Here, "shaking intensity" is used informally, as in "how intense was the shaking?" ShakeMap is now an open-source software program employed to automatically produce a suite of maps and products that portray the geographical extent and severity of potentially damaging shaking following an earthquake. It is routinely used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Hanshin Earthquake
The Great Hanshin Earthquake (, ) occurred on January 17, 1995, at 05:46:53 JST in the southern part of Hyōgo Prefecture, Japan, including the region of Hanshin. It measured 6.9 on the moment magnitude scale and had a maximum intensity of 7 on the JMA Seismic Intensity Scale (XI–XII on the Modified Mercalli intensity scale). The tremors lasted for approximately 20 seconds. The focus of the earthquake was located 17 km beneath its epicenter, on the northern end of Awaji Island, 20 km away from the center of the city of Kobe. At least 5,000 people died, about 4,600 of them from Kobe. Kobe, with its population of 1.5 million, was the closest major city to the epicenter and hit by the strongest tremors. It was Japan's second deadliest earthquake in the 20th century after the 1923 Great Kantō earthquake, in which more than 105,000 people died. Earthquake Most of the largest earthquakes in Japan are caused by subduction of the Philippine Sea plate or Pac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak Ground Acceleration
Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an wikt:accelerogram, accelerogram at a site during a particular earthquake. Earthquake shaking generally occurs in all three directions. Therefore, PGA is often split into the horizontal and vertical components. Horizontal PGAs are generally larger than those in the vertical direction but this is not always true, especially close to large earthquakes. PGA is an important parameter (also known as an intensity measure) for earthquake engineering, The design basis earthquake ground motion (DBEGM) is often defined in terms of PGA. Unlike the Richter magnitude scale, Richter and Moment magnitude scale, moment magnitude scales, it is not a measure of the total seismic scales#Magnitude and intensity, energy (magnitude, or size) of an earthquake, but rather of how much the earth shake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Period Ground Motion
Long-period ground motion (LPGM) refers to seismic waves that occur during a seismic event, like an earthquake or nuclear explosion, that has a frequency typically defined as less than 1 Hertz (i.e. a period of more than 1 second). These long-period waves are particularly significant in the context of tall or long structures, like bridges and high-rise buildings, as their nature causes short-period waves to dampen significantly before reaching the points more distant from the seismic event (e.g. from the ground). Furthermore, a frequency of around 1 Hz or less is also a frequency often found to resonate with these buildings. Although there is no official lower limit to the wave-frequency in LPGM, in terms of earthquakes, it is usually limited in scope between a 1 and 10 second period. The significance of resonance in buildings can be seen in buildings like the Millennium Bridge, which had to be temporarily closed due to people walking in resonance with their stepping frequency bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1933 Long Beach Earthquake
The 1933 Long Beach earthquake took place on March 10 at south of downtown Los Angeles. The epicenter was offshore, southeast of Long Beach, California, on the Newport–Inglewood Fault. The earthquake had a magnitude estimated at 6.4 , and a maximum Mercalli intensity of VIII (''Severe''). Damage to buildings was widespread throughout Southern California. It resulted in 115 to 120 fatalities and an estimated $40 million worth of property damage, equivalent to $ million in . The majority of the fatalities resulted from people running out of buildings exposing themselves to the falling debris. Damage Major damage occurred in the densely populated city of Long Beach on the south-facing coast of Los Angeles County. However, the damage was also found in the industrial area south of downtown Los Angeles. An estimated 75,000 mi2 area was impacted, being felt as far as San Joaquin Valley, Owens Valley, and Northern Baja California. The magnitude of the earthquake is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2008 Chino Hills Earthquake
The 2008 Chino Hills earthquake occurred at 11:42:15 am Pacific Time Zone, PDT (18:42:15 Coordinated Universal Time, UTC) on July 29 in Southern California, United States. The epicenter of the Moment magnitude scale, magnitude 5.4 earthquake was in Chino Hills, California, Chino Hills, c. east-southeast of downtown Los Angeles. Movement on an oblique-slip fault resulted in a maximum Mercalli intensity of VI (''Strong''). Though there were no deaths, eight people were injured, and it caused considerable damage in numerous structures throughout the area and caused some amusement park facilities to shut down their rides. The earthquake led to increased discussion regarding the possibility of a stronger earthquake in the future. Earthquake The Chino Hills earthquake was caused by oblique-slip faulting, with components of both Thrust fault, thrust and Sinistral and dextral, sinistral strike-slip tectonics, strike-slip displacement. Preliminary reports cited the Whittier Fault ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
April 2015 Nepal Earthquake
The April 2015 Nepal earthquake (also known as the Gorkha earthquake) killed 8,962 people and injured 21,952 across the countries of Nepal, India, China and Bangladesh. It occurred at on Saturday 25 April 2015, with a magnitude of Moment magnitude scale, Mw 7.8–7.9 or Surface wave magnitude, Ms 8.1 and a maximum Mercalli intensity scale, Mercalli Intensity of X (''Extreme''). Its epicenter was east of Gorkha District at Barpak, Gorkha, roughly northwest of central Kathmandu, and its hypocenter was at a depth of approximately . It was the worst natural disaster to strike Nepal since the 1934 Nepal–India earthquake. The ground motion recorded in Kathmandu, the capital of Nepal, was of low frequency, which, along with its occurrence at an hour when many people in rural areas were working outdoors, decreased the loss of human lives. The earthquake triggered 2015 Mount Everest avalanches, an avalanche on Mount Everest, killing 22 people, the deadliest incident on the mountain o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2011 Tohoku Earthquake And Tsunami
Eleven or 11 may refer to: *11 (number) * One of the years 11 BC, AD 11, 1911, 2011 Literature * ''Eleven'' (novel), a 2006 novel by British author David Llewellyn *''Eleven'', a 1970 collection of short stories by Patricia Highsmith *''Eleven'', a 2004 children's novel in The Winnie Years by Lauren Myracle *''Eleven'', a 2008 children's novel by Patricia Reilly Giff *''Eleven'', a short story by Sandra Cisneros Music * Eleven (band), an American rock band * Eleven: A Music Company, an Australian record label *Up to eleven, an idiom from popular culture, coined in the movie ''This Is Spinal Tap'' Albums * ''11'' (The Smithereens album), 1989 * ''11'' (Ua album), 1996 * ''11'' (Bryan Adams album), 2008 * ''11'' (Sault album), 2022 * ''Eleven'' (Harry Connick, Jr. album), 1992 * ''Eleven'' (22-Pistepirkko album), 1998 * ''Eleven'' (Sugarcult album), 1999 * ''Eleven'' (B'z album), 2000 * ''Eleven'' (Reamonn album), 2010 * ''Eleven'' (Martina McBride album), 2011 * ''Eleven'' (Mr F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Cape Mendocino. The total number of aftershocks that followed the events exceeded 2,000. The three shocks damaged and destroyed homes and businesses in Humboldt County and injured up to 356 people, but the single largest loss was due to a post-earthquake fire that consumed a business center in Scotia. Accelerometers that had been in place in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2004 Chūetsu Earthquake
The occurred in Niigata Prefecture, Japan, at 17:56 local time (08:56 UTC) on Saturday, October 23, 2004. The Japan Meteorological Agency (JMA) named it the .震度データベース検索（地震別検索結果） Japan Meteorological Agency（Japanese） Retrieval 2018/04/03 Niigata Prefecture is located in the of , the largest island of Japan. The initial earthquake had a magnitude of 6.6 and caused noticeable shaking across almost half of Honshu, including parts of the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1992 Landers Earthquake
The 1992 Landers earthquake occurred on Sunday, June 28 with an epicenter near the town of Landers, California, in San Bernardino County. The shock had a moment magnitude of 7.3 and a maximum Mercalli intensity of IX (''Violent''). Earthquake At 4:57 a.m. local time (11:57 UTC) on June 28, 1992, a magnitude 7.3 earthquake awoke much of Southern California. Though it turned out it was not the so-called " Big One" as many people would think, it was still a very strong earthquake. The shaking lasted for two to three minutes. Although this earthquake was much more powerful than the 1994 Northridge earthquake, the damage and loss of life were minimized by its location in the sparsely populated Mojave Desert. The earthquake was a right-lateral strike-slip event, and involved the rupture of several different faults over a length of . The names of those that were involved are the Johnson Valley, Kickapoo (also known as Landers), Homestead Valley, Homestead/Emerson, Emerson Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
