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1981 Dawu Earthquake
The 1981 Dawu earthquake occurred on , in Sichuan, China. Registering a surface wave magnitude of 6.8, the earthquake killed about 150 people and injured roughly 300 more. It caused comprehensive damage within close range of its epicenter. Background China has an extensive history of catastrophic earthquakes that ranges back to 1290. The first verified earthquake took place in Chih-li, killing roughly 100,000 people. The next great earthquake was probably the 1556 Shaanxi earthquake, the most devastating earthquake of all time. Roughly 830,000 were killed by the event. Other earthquakes in 1917, 1918, 1920, 1923, 1925, 1927, 1931, 1932, 1933, 1948, 1950, 1966, 1969, 1970, 1974, 1975, 1976 each killed at least one thousand people. Since 1981, earthquake fatalities have diminished greatly, though have not been stopped. As recently as 2008, an earthquake in Sichuan killed nearly 90,000 people. Characteristics The epicenter was pinpointed to Dawu County in Sichuan. Its offici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Standard Time
The time in China follows a single standard time offset of UTC+08:00 (eight hours ahead of Coordinated Universal Time), even though the country spans almost five geographical time zones. The official national standard time is called ''Beijing Time'' (BJT, ) domestically and ''China Standard Time'' (CST) internationally. Daylight saving time has not been observed since 1991. China Standard Time (UTC+8) is consistent across Mainland China, Hong Kong, Macau, Taiwan, Philippines, Singapore, Brunei, Mongolia, etc. History In the 1870s, the Shanghai Xujiahui Observatory was constructed by a French Catholic missionary. In 1880s officials in Shanghai French Concession started to provide a time announcement service using the Shanghai Mean Solar Time provided by the aforementioned observatory for ships into and out of Shanghai. By the end of 19th century, the time standard provided by the observatory had been switched to GMT+08:00. The practice has spread to other coastal ports, and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1981 Earthquakes
Events January * January 1 ** Greece enters the European Economic Community, predecessor of the European Union. ** Palau becomes a self-governing territory. * January 10 – Salvadoran Civil War: The Farabundo Martí National Liberation Front, FMLN launches its first major offensive, gaining control of most of Morazán Department, Morazán and Chalatenango Department, Chalatenango departments. * January 15 – Pope John Paul II receives a delegation led by Polish Solidarity (Polish trade union), Solidarity leader Lech Wałęsa at the Vatican City, Vatican. * January 20 – Iran releases the 52 Americans held for 444 days, minutes after Ronald Reagan is First inauguration of Ronald Reagan, sworn in as the 40th President of the United States, ending the Iran hostage crisis. * January 21 – The first DMC DeLorean, DeLorean automobile, a stainless steel sports car with gull-wing doors, rolls off the production line in Dunmurry, Northern Ireland. * January 24 – An 1981 Dawu ea ... [...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] |
Coulomb Stress Transfer
Coulomb stress transfer is a seismic-related geological process of stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during earthquakes, the computed Coulomb stress changes suggest that the stress relieved during an earthquake not only dissipates but can also move up and down fault segments, concentrating and promoting subsequent tremors. Importantly, Coulomb stress changes have been applied to earthquake-forecasting models that have been used to assess potential hazards related to earthquake activity. Coulomb stress change The Coulomb failure criterion requires that the Coulomb stress exceeds a value σf defined by the shear stress τB, normal stress σB, pore pressure p, and coefficient of friction μ of a failure plane, such that It is also often assumed that changes in pore fluid pressure induced by changes in stress are proportional to the normal stress change across the fault plane. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xianshuihe Fault System
The Xianshuihe fault system is a major active sinistral (left-lateral) strike-slip fault zone in southwestern China, at the eastern edge of the Tibetan Plateau. It has been responsible for many major earthquakes, and is one of the most seismically active fault zones in this part of China. Tectonic setting The Xianshuihe fault system lies within the complex zone of continental collision between the Indian Plate and the Eurasian Plate. It forms one of a set of sinistral fault zones that help accommodate the eastward spreading of the Tibetan Plateau. The fault zone defines the northern and eastern edges of the Sichuan-Yunnan block, and the southeastern boundary of the Bayan Har block. Geometry The Xianshuihe fault system comprises several distinct segments, with an overall length of about 350 km. The main segments are the Ganzi (or Ganzi-Yushu), the Xianshuihe, the Anninghe-Zemuhe, and the Xiaojiang faults. Seismicity Movements on this fault system have been responsible for man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Mechanism
The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is also known as a fault-plane solution. Focal mechanisms are derived from a solution of the moment tensor for the earthquake, which itself is estimated by an analysis of observed seismic waveforms. The focal mechanism can be derived from observing the pattern of "first motions", that is, whether the first arriving P waves break up or down. This method was used before waveforms were recorded and analysed digitally and this method is still used for earthquakes too small for easy moment tensor solution. Focal mechanisms are now mainly derived using semi-automatic analysis of the recorded waveforms. Moment tensor solutions The moment tensor solution is typically displayed graphically using a so-called ''beachball'' diagram. The pattern of en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawu County, Sichuan
Dawu County (), also written Tawu County or Daofu County (), is a county of northwestern Sichuan Province, China. It is under the administration of the Garzê Tibetan Autonomous Prefecture, and , had a population of 46,900 residing in an area of . By road it is from Kangding, the prefectural seat, and from Chengdu, the provincial capital. It borders the counties of Xinlong to the west, Kangding and Yajiang to the south, and Jinchuan and Zamtang of Ngawa Prefecture Ngawa Tibetan and Qiang Autonomous Prefecture, also known as Aba (; Qiang: ; ), is an autonomous prefecture of northwestern Sichuan, bordering Gansu to the north and northeast and Qinghai to the northwest. Its seat is in Barkam, and it has an ar ... as well as Luhuo to the north. In January 1981 it was struck by an 1981 Dawu earthquake, earthquake. Climate References External links See this link for a book-length study of a Tibetan village in Dawu County: * http://tibetanplateau.wikischolars.columbia. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Natural Disasters By Death Toll
A natural disaster is a sudden event that always causes widespread destruction, major collateral damage or loss of life, brought about by forces other than the acts of human beings. A natural disaster might be caused by earthquakes, flooding, volcanic eruption, landslide, hurricanes etc. To be classified as a disaster, it will have profound environmental effect and/or human loss and frequently causes financial loss. Ten deadliest natural disasters by highest estimated death toll excluding epidemics and famines This list takes into account only the highest estimated death toll for each disaster, and lists them accordingly. It does not include epidemics and famines. It does not include several volcanic eruptions with uncertain death tolls resulting from collateral effects such as crop failures; see List of volcanic eruptions by death toll. The list also does not include the 1938 Yellow River flood, which was caused by the deliberate destruction of dikes. Deadliest natural disa ... [...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 blur the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1556 Shaanxi Earthquake
The 1556 Shaanxi earthquake (formerly romanized ''Shensi''), known in Chinese colloquially by its regnal year as "" ('' Jiājìng Dàdìzhèn'') or officially by its epicenter as "" ('' Huàxiàn Dìzhèn''), occurred in the early morning of 23 January 1556 in Huaxian, Shaanxi during the Ming dynasty. Most of the residents there lived in yaodongs—artificial caves in loess cliffs—which collapsed and buried alive those sleeping inside. Modern estimates put the direct deaths from the earthquake at over 100,000, while over 700,000 migrated away or died from famine and plagues, which summed up to a total loss of 830,000 people in Imperial records.颤抖的地球—地震科学' rembling Earth: On Seismology(2005). Researched by China Earthquake Administration seismologists 冯万鹏,薑文亮,龚丽霞,公茂盛,胡进军; Revised by CEA seismologists 王文清,续春荣,张宝红; Edited by CEA chiefs 谢礼立,张景发. Tsinghua University Press. Pages XIII, 162. "1556年陕 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebei
Hebei or , (; alternately Hopeh) is a northern province of China. Hebei is China's sixth most populous province, with over 75 million people. Shijiazhuang is the capital city. The province is 96% Han Chinese, 3% Manchu, 0.8% Hui, and 0.3% Mongol. Three Mandarin dialects are spoken: Jilu Mandarin, Beijing Mandarin and Jin. Hebei borders the provinces of Shanxi to the west, Henan to the south, Shandong to the southeast, Liaoning to the northeast, and the Inner Mongolia Autonomous Region to the north. Its economy is based on agriculture and manufacturing. The province is China's premier steel producer, although the steel industry creates serious air pollution. Five UNESCO World Heritage Sites can be found in the province, the: Great Wall of China, Chengde Mountain Resort, Grand Canal, Eastern Qing tombs, and Western Qing tombs. It is also home to five National Famous Historical and Cultural Cities: Handan, Baoding, Chengde, Zhengding and Shanhaiguan. Historic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
