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2022 Michoacán Earthquake
On 19 September 2022, a moment magnitude 7.7 earthquake struck between the Mexican states of Michoacán and Colima at 13:05:06 local time. The earthquake had a depth of , resulting in a maximum intensity of VIII (''Severe'') on the Modified Mercalli intensity scale. The USGS reported the epicentre was southeast of the town of Aquila (near the municipality of Coalcomán). Two people were killed and at least 35 others were injured across several states. A magnitude 6.8 aftershock struck on 22 September, causing three more deaths. The earthquake coincidentally occurred on the 37th anniversary of the 1985 Mexico City earthquake, which killed around 10,000 people, and the fifth anniversary of the 2017 Puebla earthquake that struck the state of Puebla and killed 370 people. A national earthquake drill was being held shortly after midday, less than an hour before the earthquake struck. Tectonic setting This shallow earthquake occurred in a seismically active zone near the coast o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1985 Mexico City Earthquake
The 1985 Mexico City earthquake struck in the early morning of 19 September at 07:17:50 (CST) with a moment magnitude of 8.0 and a maximal Mercalli intensity of IX (''Violent''). The event caused serious damage to the Greater Mexico City area and the deaths of at least 5,000 people. The sequence of events included a foreshock of magnitude 5.2 that occurred the prior May, the main shock on 19 September, and two large aftershocks. The first of these occurred on 20 September with a magnitude of 7.5 and the second occurred seven months later on 30 April 1986 with a magnitude of 7.0. They were located off the coast along the Middle America Trench, more than away, but the city suffered major damage due to its large magnitude and the ancient lake bed that Mexico City sits on. The event caused between three and five billion USD in damage as 412 buildings collapsed and another 3,124 were seriously damaged in the city. Then-president Miguel de la Madrid and the ruling Institutional Rev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Colima-Jalisco Earthquake
File:1995 Events Collage V2.png, From left, clockwise: O.J. Simpson is acquitted of the murders of Nicole Brown Simpson and Ronald Goldman from the year prior in "The Trial of the Century" in the United States; The Great Hanshin earthquake strikes Kobe, Japan, killing 5,000-6,000 people; The Unabomber Manifesto is published in several U.S. newspapers; Gravestones mark the victims of the Srebrenica massacre near the end of the Bosnian War; Windows 95 is launched by Microsoft for PC; The first exoplanet, 51 Pegasi b, is discovered; Space Shuttle Atlantis docks with the Space station Mir in a display of U.S.-Russian cooperation; The Alfred P. Murrah Federal Building in Oklahoma City is bombed by domestic terrorists, killing 168., 300x300px, thumb rect 0 0 200 200 O. J. Simpson murder case rect 200 0 400 200 Kobe earthquake rect 400 0 600 200 Unabomber Manifesto rect 0 200 300 400 Oklahoma City bombing rect 300 200 600 400 Srebrenica massacre rect 0 400 200 600 Space Shuttle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular ''klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is referred to as a ''blind thrust'' fault. Because of the lack of surface evidence, blind thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Colima–Jalisco Earthquake
The 1995 Colima–Jalisco earthquake occurred on October 9 at 15:35 UTC with a moment magnitude of 8.0 and a maximum Mercalli intensity of VIII (''Severe''). The shock occurred off the coast of Jalisco, Mexico, where a tsunami was triggered that affected a stretch of the coast. The earthquake could be felt in Mexico City and in high-rise buildings in Dallas and Houston. In Mexico, the Cihuatlan-Manzanillo was the most severely affected area. At least 49 people died and 100 were injured. Tectonic setting This earthquake occurred in the area where the Rivera Plate subducts beneath the North American Plate. It was the result of the relative movements between the North American Plate, the Rivera Plate, and the Cocos Plate. Damage Although the tsunami affected a 200 km stretch of coast, severe damage was confined to areas with shallow shoreline topography. Most of the flooding occurred in the Tenacatita Bay area. Landslides blocked roads between Guadalajara and Manzanillo. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2003 Colima Earthquake
The 2003 Colima earthquake occurred on 21 January with a moment magnitude of 7.6 and a maximum Mercalli intensity of VIII (''Severe''). The epicenter was located on the Pacific coast in the Mexican state of Colima. The earthquake was felt as far away as Mexico City and in southern parts of the United States. Effects The 2003 Colima earthquake resulted the 29 deaths and 300 injuries. Additionally, approximately 10,000 were left homeless as the earthquake destroyed 2,005 homes and seriously damaged 6,615. Most of the deaths and damage occurred in Villa de Álvarez, a city which borders the northern part of the city of Colima. Extensive damage (rating VIII) occurred in the city of Colima and in Tecomán. Some deaths and damage occurred in the states of Jalisco and Michoacán and a few buildings were damaged as far away as Guanajuato and Morelos. The quake was felt strongly (rating VI) in parts of Mexico City. It was also felt in most of Mexico and in the United States in Corpus C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1932 Jalisco Earthquake
The 1932 Jalisco earthquakes began on June 3 at 10:36 UTC with a megathrust event that registered 8.1 on the moment magnitude scale. With a maximum perceived intensity of X (''Extreme'') on the Mercalli intensity scale, at least 400 deaths were caused in Mexico and neighboring Guatemala. It was the first of a series of seismic events that affected parts of western Mexico during the month of June 1932, all reaching magnitude 7 or greater. The Mexican subduction zone, the Middle America Trench, is seismically active and has generated both destructive and non-destructive tsunamis. Each earthquake in the series caused significant damage, injuries, and deaths, and in each case tsunamis of various heights were generated, with the June 22 catastrophic tsunami in Cuyutlán and San Blas being described as one of the most destructive events in the region based on all available historical records. Tectonic setting This part of Mexico lies on a complex convergent boundary where the Rivera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocos Plate
The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. The Cocos Plate also broke into two pieces, creating the small Rivera Plate. The Cocos Plate is bounded by several different plates. To the northeast it is bounded by the North American Plate and the Caribbean Plate. To the west it is bounded by the Pacific Plate and to the south by the Nazca Plate. __TOC__ Geology The Cocos Plate was created by sea floor spreading along the East Pacific Rise and the Cocos Ridge, specifically in a complicated area geologists call the Cocos-Nazca spreading system. From the rise the plate is pushed eastward and pushed or dragged (perhaps both) under the less dense Caribbean Plate, in the process called subduction. The subducted leading edge heats ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rivera Plate
The Rivera Plate is a small tectonic plate (a microplate) located off the west coast of Mexico, just south of the Baja California Peninsula. It is bounded on the northwest by the East Pacific Rise, on the southwest by the Rivera Transform Fault, on the southeast by a deformation zone, and on the northeast by the Middle America Trench and another deformation zone. The Rivera Plate is believed to have separated from the Cocos Plate located to its southeast about 5–10 million years ago. Seismicity and tomography images show that the Rivera plate dips at 40° beneath the forearc region and then dips ~70° beneath the Trans-Mexican Volcanic Belt. The subduction of the Rivera Plate under the North American Plate, in the Mid-American Trench, has been the cause of the strongest earthquakes in the history of Mexico, including the largest earthquake in Mexico during the 20th century which occurred on June 3, 1932 in the state of Jalisco. The quake had a magnitude of 8.2 with a magnit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Plate
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific Plate (which borders the plate to the west). It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust. The interior of the main continental landmass includes an extensive granitic core called a craton. Along most of the edges of this craton are fragments of crustal material called terranes, which are accreted to the craton by tectonic actions over a long span of time. It is thought that much of North America west of the Rocky Mountains is composed of such terranes. Boundaries The southern boundary with the Cocos Plate to the west and the Caribbean Plate to the east is a transform fault, represented by the Swan Islands Transform Fault unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
