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Denali Fault
The Denali Fault is a major intracontinental dextral (right lateral) Fault (geology)#Strike-slip faults, strike-slip fault in western North America, extending from northwestern British Columbia, Canada to the central region of the U.S. state of Alaska. Location The Denali Fault is located in the southern half of Alaska in the Alaska Range. It is more than 1,250 miles long, arcing through southern Alaska, southwestern Yukon, and back into southeastern Alaska. The steep north face of Denali, known as the Wickersham Wall, rises 15,000 feet from its base, and is a result of relatively recent vertical movement along the fault. Effects Alaska's network of faults is a result of tectonic activity; the Pacific plate is actively subducting (sliding under) the North American plate, and the Denali Fault is located on the boundary between the two plates. Along the Denali Fault, lateral and vertical offset movement is taking place at a rate of approximately 13 mm/yr. Around 300 to 4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2002 Denali Earthquake
The 2002 Denali earthquake occurred at 22:12:41 UTC (1:12 PM Alaska Time Zone, Local Time) November 3 with an epicenter 66 km ESE of Denali National Park, Alaska, United States. This 7.9 Moment magnitude scale, Mw earthquake was the largest recorded in the United States in 37 years (after the 1965 Rat Islands earthquake). The shock was the strongest ever recorded in the interior of Alaska. Due to the remote location, there were no fatalities and only one injury. Due to the shallow depth, it was felt at least as far away as Seattle and it generated seiches on bodies of water as far away as Texas and New Orleans, Louisiana. About 20 houseboats were damaged by a seiche on a lake in Washington State. Tectonic setting The Denali Fault, Denali-Totschunda fault is a major dextral (right lateral) Fault (geology)#Strike-slip faults, strike-slip system, similar in scale to the San Andreas Fault system. In Alaska, moving from east to west, the plate interactions change from a transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moment Magnitude Scale
The moment magnitude scale (MMS; denoted explicitly with or Mwg, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori. Similar to the local magnitude scale, local magnitude/Richter scale () defined by Charles Francis Richter in 1935, it uses a logarithmic scale; small earthquakes have approximately the same magnitudes on both scales. Despite the difference, news media often use the term "Richter scale" when referring to the moment magnitude scale. Moment magnitude () is considered the authoritative magnitude scale for ranking earthquakes by size. It is more directly related to the energy of an earthquake than other scales, and does not saturatethat is, it does not underestimate magnitudes as other scales do in certain conditions. It has become the standard scale used by seismological authorities like the United State ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of British Columbia
The geology of British Columbia is a function of its location on the leading edge of the North American continent. The mountainous physiography and the diversity of the different types and ages of rock hint at the complex geology, which is still undergoing revision despite a century of exploration and mapping. The province's most prominent geological features are its mountain ranges, including the North American Cordillera which stretches from Southern Mexico to Alaska. Terrane theory Terrane theory was first proposed by Jim Monger of the Geological Survey of Canada and Charlie Rouse in 1971 as an explanation for a set of fusulinid fossils that were found in central British Columbia. Rather than suggest that facies changes or seaways were behind this (which were common explanations at the time), the two geologists proposed that the fossils in question had been part of an assemblage of rocks that had migrated across the Pacific Ocean to their present location. This theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic Faults Of Alaska
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 Miletus () ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic Faults Of Canada
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...s (or generally, quakes) and the generation and propagation of elastic waves through planetary bodies. It also includes studies of the earthquake environmental effects, environmental effects of earthquakes such as tsunamis; other seismic sources such as volcanoes, plate tectonics, glaciers, Fluvial seismology, rivers, oceanic microseisms, and the atmosphere; and induced seismicity, 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 fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tintina Fault
The Tintina Fault is a large right-lateral fault (geology), strike-slip fault in western North America, extending from Flathead Lake, Flathead Lake, Montana to the centre of the U.S. state of Alaska. It represents the Yukon continuum between the Rocky Mountain Trench in the northern United States and the Kaltag Fault in Alaska. Unlike the Denali Fault, which ruptured a portion of its central segment during the 2002 Denali earthquake, the Tintina Fault is considered inactive. Despite this classification, researchers noted a magnitude 5.3 right-lateral event in 1972 and a relatively young (Holocene) scarp with a maximum offset of . See also *Northern Cordilleran Volcanic Province *Rocky Mountain Trench References Further reading * Seismic faults of Canada Seismic faults of Alaska Geology of British Columbia Geology of Yukon Strike-slip faults Geology of Montana {{struct-geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault Trace
A fault trace describes the intersection of a Fault (geology), geological fault with the Earth's surface, which leaves a visible disturbance on the surface, usually looking like a crack in the surface with jagged rock structures protruding outward. The term also applies to a line plotted on a geological map to represent a fault. These fractures tend to occur when a Slope stability, slip surface expands from a fault core, especially during an earthquake. This tends to occur with fault displacement, in which surfaces on both sides of a fault, known as fault blocks, separate horizontally or vertically. Traces caused by different faults Fault (geology), Faults, at the broadest level, can be differentiated by the relative motion between their fault blocks. Horizontal motion is indicative of what is known as a Strike-slip Fault, strike-slip fault and does not usually show much vertical separation. This is when the motion along the fault is parallel to the fault trace, usually cause ... [...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] |
Totschunda Fault
The Totschunda Fault is a major active dextral (right-lateral) continental strike-slip fault in southeastern Alaska. It forms a link between the Denali Fault to the northwest and the Fairweather Fault to the southeast. The northwestern end of the fault ruptured during the 2002 Denali earthquake. Based on radiometric dating of a dike that cuts fault rock associated with the Totschunda Fault to about 114 million years ago, the fault zone was initiated during the latter part of the Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ..., associated with the accretion of the Wrangellia Terrane. References Seismic faults of Alaska {{Alaska-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchorage
Anchorage, officially the Municipality of Anchorage, is the most populous city in the U.S. state of Alaska. With a population of 291,247 at the 2020 census, it contains nearly 40 percent of the state's population. The Anchorage metropolitan area, which includes Anchorage and the neighboring Matanuska-Susitna Borough, had a population of 398,328 in 2020, accounting for more than half the state's population. At of land area, the city is the fourth-largest by area in the U.S. Anchorage is in Southcentral Alaska, at the terminus of the Cook Inlet, on a peninsula formed by the Knik Arm to the north and the Turnagain Arm to the south. First settled as a tent city near the mouth of Ship Creek in 1915 when construction on the Alaska Railroad began, Anchorage was incorporated as a city in November 1920. In September 1975, the City of Anchorage merged with the Greater Anchorage Area Borough, creating the Municipality of Anchorage. The municipal city limits span , encompassin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisiana
Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25th in population, with roughly 4.6 million residents. Reflecting its French heritage, Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). Baton Rouge is the state's capital, and New Orleans, a French Louisiana region, is its most populous city with a population of about 363,000 people. Louisiana has a coastline with the Gulf of Mexico to the south; a large part of its eastern boundary is demarcated by the Mississippi River. Much of Louisiana's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas of coastal marsh a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
