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2022 Michoacán Earthquake
On 19 September 2022, a moment magnitude 7.6–7.7 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 southwest 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The agency also makes maps of planets and moons, based on data from U.S. space probes. The sole scientific agency of the U.S. Department of the Interior, USGS is a fact-finding research organization with no regulatory responsibility. It is headquartered in Reston, Virginia, with major offices near Lakewood, Colorado; at the Denver Federal Center; and in NASA Research Park in California. In 2009, it employed about 8,670 people. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on its hundredth anniversary, was "Earth Science in the Pub ... [...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 scale, moment magnitude of 8.0 and a maximal Modified Mercalli intensity scale, 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 on which Mexico City sits. 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-pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Colima-Jalisco Earthquake
1995 was designated as: * United Nations Year for Tolerance * World Year of Peoples' Commemoration of the Victims of the Second World War This was the first year that the Internet was entirely privatized, with the United States government no longer providing public funding, marking the beginning of the Information Age. America Online and Prodigy (online service), Prodigy offered access to the World Wide Web system for the first time this year, releasing browsers that made it easily accessible to the general public. Events January * January 1 ** The World Trade Organization (WTO) is established to replace the General Agreement on Tariffs and Trade (GATT). ** Austria, Finland and Sweden join the European Union. * January 9 – Valeri Polyakov completes 366 days in space while aboard then ''Mir'' space station, breaking a duration record. * January 10–January 15, 15 – The World Youth Day 1995 festival is held in Manila, Manila, Philippines, culminating in 5 million people ... [...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 called a ''blind thrust'' fault. Because of the lack of surface evidence, blind thrust fa ... [...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. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2003 Colima Earthquake
An earthquake struck the Pacific Coast of Mexico on 21 January 2003 with a moment magnitude of 7.5. It had a maximum Mercalli intensity of VIII (''Severe''). The epicenter was located on the Pacific coast near the Mexican state of Colima. The earthquake killed 29 people, injured 1,073 others and damaged over 43,300 homes across five states, with minor damage also occurring in Mexico City. The earthquake was felt as far away as the states of Texas and Louisiana. Tectonic setting This shallow earthquake occurred in a seismically active zone near the coast of central Mexico. The earthquake occurred near the juncture of three tectonic plates: the North American plate to the northeast, the Rivera plate to the northwest, and the Cocos plate to the south. Both the Rivera plate and the Cocos plate are being subsumed beneath the North American plate. The slower subducting Rivera plate is moving northwest at about 2 cm per year relative to the North American plate and the faster Cocos ... [...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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other 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 rates of convergence as high as 11 cm/year. Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own ... [...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 mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed during the first decades of the 20th century. Plate tectonics came to be accepted by Earth science, geoscientists after seafloor spreading was validated in the mid-to-late 1960s. The processes that result in plates and shape Earth's crust are called ''tectonics''. Tectonic plates also occur in other planets and moons. Earth's lithosphere, the rigid outer shell of the planet including the crust (geology), crust and upper mantle, is fractured 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 (or fault (geology), fault): , , or . The relative movement of the plates typically ranges from zero to 10 cm annu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
