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1931 Valentine Earthquake
In the early morning hours of August 16, 1931, a powerful earthquake occurred in West Texas with a maximum Mercalli intensity scale, Mercalli intensity of VIII (''Severe''). Estimates of its Seismic magnitude scales, magnitude range between 5.8–6.4 Seismic magnitude scales#mb scale, mb, making it the most powerful earthquake ever recorded in Texas history. Its epicenter was near the town of Valentine, Texas; there, the earthquake caused damage to many homes and buildings. The earthquake may have been caused by movement along fault (geology)#Oblique-slip faults, oblique-slip faulting in West Texas, the most seismically-active region in the state. Shaking from the earthquake was perceptible within a radius of the epicenter, affecting four U.S. states and northern Mexico. Several foreshocks and aftershocks accompanied the primary temblor, with the aftershocks continuing until at least November 3, 1931. The main earthquake caused no fatalities, though several peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ShakeMap
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Paso, Texas
El Paso (; "the pass") is a city in and the county seat, seat of El Paso County, Texas, El Paso County in the western corner of the U.S. state of Texas. The 2020 population of the city from the United States Census Bureau, U.S. Census Bureau was 678,815, making it the List of United States cities by population, 23rd-largest city in the U.S., the List of cities in Texas by population, sixth-largest city in Texas, and the second-largest city in the Southwestern United States behind Phoenix, Arizona. The city is also List of U.S. cities with large Hispanic populations, the second-largest majority-Hispanic city in the U.S., with 81% of its population being Hispanic. Its metropolitan statistical area covers all of El Paso and Hudspeth County, Texas, Hudspeth counties in Texas, and had a population of 868,859 in 2020. El Paso has consistently been ranked as one of the safest large cities in America. El Paso stands on the Rio Grande across the Mexico–United States border from Ciuda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). The coordination of time and frequency transmissions around the world began on 1 January 1960. UTC was first officially adopted as CCIR Recommendation 374, ''Standard-Frequency and Time-Signal Emissions'', in 1963, but the official abbreviation of UTC and the official English name of Coordinated Universal Time (along with the French equivalent) were not adopted until 1967. The system has been adjusted several times, including a brief period during which the time-coordination radio signals broadcast both UTC and "Stepped Atomic Time (SAT)" before a new UTC was adopted in 1970 and implemented in 1972. This change also a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Standard Time
The North American Central Time Zone (CT) is a time zone in parts of Canada, the United States, Mexico, Central America, some Caribbean Islands, and part of the Eastern Pacific Ocean. Central Standard Time (CST) is six hours behind Coordinated Universal Time (UTC). During summer, most of the zone uses daylight saving time (DST), and changes to Central Daylight Time (CDT) which is five hours behind UTC. The largest city in the Central Time Zone is Mexico City; the Mexico City metropolitan area is the largest metropolitan area in the zone and in North America. Regions using (North American) Central Time Canada The province of Manitoba is the only province or territory in Canada that observes Central Time in all areas. The following Canadian provinces and territories observe Central Time in the areas noted, while their other areas observe Eastern Time: * Nunavut (territory): western areas (most of Kivalliq Region and part of Qikiqtaaluk Region) * Ontario (province): a port ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvium
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium. Floodplain alluvium can be highly fertile, and supported some of the earliest human civilizations. Definitions The present consensus is that "alluvium" refers to loose sediments of all types deposited by running water in floodplains or in alluvial fans or related landforms. However, the meaning of the term has varied considerably since it was first defined in the French dictionary of Antoine Furetière, posthumously published in 1690. Drawing upon concepts from Roman law, Furetière defined ''alluvion'' (the F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reno, Nevada
Reno ( ) is a city in the northwest section of the U.S. state of Nevada, along the Nevada-California border, about north from Lake Tahoe, known as "The Biggest Little City in the World". Known for its casino and tourism industry, Reno is the county seat and largest city of Washoe County and sits in the High Eastern Sierra foothills, in the Truckee River valley, on the eastern side of the Sierra Nevada. The Reno metro area (along with the neighboring city Sparks) occupies a valley colloquially known as the Truckee Meadows which because of large-scale investments from Greater Seattle and San Francisco Bay Area companies such as Amazon, Tesla, Panasonic, Microsoft, Apple, and Google has become a new major technology center in the United States. The city is named after Civil War Union Major General Jesse L. Reno, who was killed in action during the American Civil War at the Battle of South Mountain, on Fox's Gap. Reno is part of the Reno–Sparks metropolitan area, the ... [...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 affects the Earth's surface. Surface rupture is opposed by 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, 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. __TOC__ 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 of 6.7, caused major damage in the Los Angeles area, occurred at below the Earth's surface, but did not cause surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismological Society Of America
The Seismological Society of America (SSA) is an international scientific society devoted to the advancement of seismology and the understanding of earthquakes for the benefit of society. Founded in 1906, the society has members throughout the world representing seismologists and other geophysicists, geologists, engineers, insurers, and policy-makers in preparedness and safety. History The society was established by academic, government, and other scientific and engineering professionals in the months following the April 18th San Francisco earthquake, with the first meeting of the Board of Directors taking place on December 1, 1906. Publications The Seismological Society of America publishes the ''Bulletin of the Seismological Society of America'' (''BSSA''), a journal of research in earthquake seismology and related disciplines since 1911, and ''Seismological Research Letters'' (''SRL''), which serves as a forum for informal communication among seismologists, as well as betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rake (geology)
In structural geology, rake (or pitch) is formally defined as "the angle between a line r a featureand the strike line of the plane in which it is found", measured on the plane. The three-dimensional orientation of a line can be described with just a plunge and trend. The rake is a useful description of a line because often (in geology) features (lines) follow along a planar surface. In these cases the rake can be used to describe the line's orientation in three dimensions relative to that planar surface. One might also expect to see this used when the particular line is hard to measure directly (possibly due to outcrops impeding measurement). The rake always sweeps down from the horizontal plane. Fault motion Rake is used to describe the direction of fault motion with respect to the strike (measured anticlockwise from the horizontal, up is positive; values between −180° and 180°): * left-lateral strike slip: rake near 0° * right-lateral strike slip: rake near 180 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike And Dip
Strike and dip is a measurement convention used to describe the orientation, or attitude, of a planar geologic feature. A feature's strike is the azimuth of an imagined horizontal line across the plane, and its dip is the angle of inclination measured downward from horizontal. They are used together to measure and document a structure's characteristics for study or for use on a geologic map. A feature's orientation can also be represented by dip and dip direction, using the azimuth of the dip rather than the strike value. Linear features are similarly measured with trend and plunge, where "trend" is analogous to dip direction and "plunge" is the dip angle. Strike and dip are measured using a compass and a clinometer. A compass is used to measure the feature's strike by holding the compass horizontally against the feature. A clinometer measures the features dip by recording the inclination perpendicular to the strike. These can be done separately, or together using a tool such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Of The Seismological Society Of America
''Bulletin of the Seismological Society of America'' (BSSA) is a bimonthly peer reviewed scientific journal published by the Seismological Society of America. The editor-in-chief is Thomas Pratt ( U. S. Geological Survey). The journal covers seismology and related disciplines. Topical coverage includes theory and observation of seismic waves, specific earthquakes, the structure of the Earth, earthquake sources, hazard and risk estimation, and earthquake engineering. Publishing formats include regular papers and short notes. Publication has been continuous since 1911. Abstracting and indexing This journal is indexed by the following services:Hollis Classic Library Harvard College. 2009 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Grande Rift
The Rio Grande rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. The rift extends from central Colorado in the north to the state of Chihuahua, Mexico, in the south. The rift zone consists of four basins that have an average width of . The rift can be observed on location at Rio Grande National Forest, White Sands National Park, Santa Fe National Forest, and Cibola National Forest, among other locations. The Rio Grande rift has been an important site for humans for a long time, because it provides a north–south route that follows a major river. The Rio Grande follows the course of the rift from southern Colorado to El Paso, where it turns southeast and flows toward the Gulf of Mexico. Important cities, including Albuquerque, Santa Fe, Taos, Española, Las Cruces, El Paso, and Ciudad Juárez, lie within the rift. Geology The Rio Grande rift represents the easternmost ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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