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1718 Tongwei–Gansu Earthquake
The 1718 Tongwei–Gansu earthquake occurred on June 19, 1718 in Tongwei County, Gansu Province, Qing dynasty, present-day China. The estimated surface wave magnitude 7.5 earthquake was assigned a maximum Modified Mercalli intensity of X (''Extreme''), causing tremendous damage and killing 73,000 people. Tectonic setting The active plate tectonics of Gansu Province located on the Tibetan Plateau is dominated by the north–south continental collision of the Indian Plate and Eurasian Plate. As the Indian Plate collides along a convergent plate boundary known as the Main Himalayan Thrust, it being of continental crust does not subduct, rather, it plows into the Eurasian Plate. This process severely deforms the Eurasian Plate, uplifting the crust, forming the Tibetan Plateau. The force of the Indian Plate converging pushes the Tibetan Plateau east, towards the Sichuan Basin, forming another zone of collision. This collision and resulting crustal deformation of the Eurasian Plate i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qing Dynasty
The Qing dynasty ( ), officially the Great Qing,, was a Manchu-led imperial dynasty of China and the last orthodox dynasty in Chinese history. It emerged from the Later Jin dynasty founded by the Jianzhou Jurchens, a Tungusic-speaking ethnic group who unified other Jurchen tribes to form a new "Manchu" ethnic identity. The dynasty was officially proclaimed in 1636 in Manchuria (modern-day Northeast China and Outer Manchuria). It seized control of Beijing in 1644, then later expanded its rule over the whole of China proper and Taiwan, and finally expanded into Inner Asia. The dynasty lasted until 1912 when it was overthrown in the Xinhai Revolution. In orthodox Chinese historiography, the Qing dynasty was preceded by the Ming dynasty and succeeded by the Republic of China. The multiethnic Qing dynasty lasted for almost three centuries and assembled the territorial base for modern China. It was the largest imperial dynasty in the history of China and in 1790 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduct
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] |
1927 Gulang Earthquake
The 1927 Gulang earthquake occurred at 6:32 a.m. on 22 May (22:32 UTC on 21 May). This 7.6 magnitude event had an epicenter near Gulang, Gansu in the Republic of China. There were 40,912 deaths. It was felt up to 700 km (435 mi) away. Geology The continental collision between the Indian Plate and the Eurasian Plate has formed the Himalayas and the large uplifted area of the Tibetan Plateau. The northeastern part of Tibet is affected by the eastward lateral spreading of the Tibetan Plateau. This spreading is accommodated by a series of sinistral (left-lateral) strike-slip faults, including the Altyn Tagh, Haiuyan, Kunlun and Xianshuihe faults, combined with thrusting on the Longmenshan fault. The earthquake ruptured the complex thrust fault system in the Qilian Mountains transpressional zone, formed at a restraining bend on the Haiyuan fault. Another segment of the Haiyuan fault was responsible for the 1920 Haiyuan earthquake. Damage In the area of greatest i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1920 Haiyuan Earthquake
1920 Haiyuan earthquake () occurred on December 16 in Haiyuan County, Ningxia Province, Republic of China at 19:05:53. It was also called the 1920 Gansu earthquake because Ningxia was a part of Gansu Province when the earthquake occurred. It caused destruction in the Lijunbu- Haiyuan-Ganyanchi area and was assigned the maximum intensity on the Mercalli intensity scale (XII ''Extreme''). About 258,707~273,407 died, making it one of the most fatal earthquakes in China, in turn making it one of the worst disasters in China by death toll. Earthquake The earthquake hit at 19:05:53 Gansu-Sichuan time (12:05:53 UTC), reportedly 8.25 or 7.8 ML, and was followed by a series of aftershocks for three years. Damage Over 73,000 people were killed in Haiyuan County. A landslide buried the village of Sujiahe in Xiji County. More than 30,000 people were killed in Guyuan County. Nearly all the houses collapsed in the cities of Longde and Huining. Damage (VI–X) occurred in seven provinces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Live Science
Live Science is a science news website run by Future via Purch, which it purchased from Imaginova in 2009. Stories and editorial commentary are typically syndicated to major news outlets, such as Yahoo!, MSNBC, AOL, and Fox News.{{fact, date=March 2020 Live Science was originally launched in 2004, but was subsequently shut down and re-launched in 2007. Live Science covers scientific breakthroughs, research ventures and odd facts from around the world in an online newsmagazine format. Purch consumer brands (including Live Science) were acquired by Future in 2018.{{Cite web , url=https://www.futureplc.com/brand/live-science/ , title=Live Science , work=Future plc Future plc is an international multimedia company established in the United Kingdom in 1985. The company has over 220 brands that span magazines, newsletters, websites, and events in fields such as video games, technology, films, music, photogr ... , access-date=18 December 2018 References {{reflist External li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake Rupture
In seismology, an earthquake rupture is the extent of slip that occurs during an earthquake in the Earth's crust. Earthquakes occur for many reasons that include: landslides, movement of magma in a volcano, the formation of a new fault, or, most commonly of all, a slip on an existing fault. Nucleation A tectonic earthquake begins by an initial rupture at a point on the fault surface, a process known as nucleation. The scale of the nucleation zone is uncertain, with some evidence, such as the rupture dimensions of the smallest earthquakes, suggesting that it is smaller than 100 m while other evidence, such as a slow component revealed by low-frequency spectra of some earthquakes, suggest that it is larger. The possibility that the nucleation involves some sort of preparation process is supported by the observation that about 40% of earthquakes are preceded by foreshocks. However, some large earthquakes, such as the M8.6 1950 India - China earthquake., have no foreshocks and it r ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A '' fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longmenshan Fault
The Longmenshan Fault () is a thrust fault which runs along the base of the Longmen Mountains in Sichuan province in southwestern China. The strike of the fault plane is approximately NE. Motion on this fault is responsible for the uplift of the mountains relative to the lowlands of the Sichuan Basin to the east. Representing the eastern boundary of the Qinghai-Tibet Plateau, it is a border formation between the Bayan Kola block in the Plateau and the South China block in the Eurasian Plate. The 2008 Wenchuan, 2013 Lushan and 2022 Ya'an earthquakes occurred along this fault. A study by the China Earthquake Administration (CEA) states: "The late-Cenozoic deformations in this fault (''that caused the 2008 Wenchuan earthquake'') are concentrated in the Guanxian-Jiangyou fracture (hill-front fracture), Yingxiu- Beichuan fracture (mid-fracture), Wenchuan-Mao County fracture (hill-back fracture), and their related folds. The recent Ms 8.0 earthquake occurred on the Ying ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altyn Tagh Fault
The Altyn Tagh Fault (ATF) is a 2,000 km long, active, sinistral (left lateral) strike-slip fault that forms the northwestern boundary of the Tibetan Plateau with the Tarim Basin. It is one of the major sinistral strike-slip structures that together help to accommodate the eastward motion of this zone of thickened crust, relative to the Eurasian Plate. A total displacement of about ~475 km has been estimated for this fault zone since the middle Oligocene, although the amount of displacement, age of initiation and slip rate are disputed. Tectonic setting The Tibetan Plateau is an area of thickened continental crust, a result of the ongoing collision of the Indo-Australian Plate with the Eurasian Plate. The way in which this zone accommodates the collision remains unclear with two end-member models being proposed. The first regards the crust as being made up of a mosaic of strong blocks separated by weak fault zones, the 'microplate' model. The second regards the deformatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
