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Foreshock
A foreshock is an earthquake that occurs before a larger seismic event (the mainshock) and is related to it in both time and space. The designation of an earthquake as ''foreshock'', ''mainshock'' or aftershock is only possible after the full sequence of events has happened. Occurrence Foreshock activity has been detected for about 40% of all moderate to large earthquakes, and about 70% for events of M>7.0. They occur from a matter of minutes to days or even longer before the main shock; for example, the 2002 Sumatra earthquake is regarded as a foreshock of the 2004 Indian Ocean earthquake with a delay of more than two years between the two events. Some great earthquakes (M>8.0) show no foreshock activity at all, such as the M8.6 1950 India–China earthquake. The increase in foreshock activity is difficult to quantify for individual earthquakes but becomes apparent when combining the results of many different events. From such combined observations, the increase before the mai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousands of instrumentally detectable aftershocks, which steadily decrease in magnitude and frequency according to a consistent pattern. In some earthquakes the main rupture happens in two or more steps, resulting in multiple main shocks. These are known as doublet earthquakes, and in general can be distinguished from aftershocks in having similar magnitudes and nearly identical seismic waveforms. Distribution of aftershocks Most aftershocks are located over the full area of fault rupture and either occur along the fault plane itself or along other faults within the volume affected by the strain associated with the main shock. Typically, aftershocks are found up to a distance equal to the rupture length away from the fault plane. The pattern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake Prediction
Earthquake prediction is a branch of the science of seismology concerned with the specification of the time, location, and magnitude of future earthquakes within stated limits, and particularly "the determination of parameters for the ''next'' strong earthquake to occur in a region". Earthquake prediction is sometimes distinguished from '' earthquake forecasting'', which can be defined as the probabilistic assessment of ''general'' earthquake hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. Not all scientists distinguish "prediction" and "forecast", but the distinction is useful. Prediction can be further distinguished from earthquake warning systems, which upon detection of an earthquake, provide a real-time warning of seconds to neighboring regions that might be affected. In the 1970s, scientists were optimistic that a practical method for predicting earthquakes would soon be found, but by the 1990s continuing failure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1975 Haicheng Earthquake
On February 4, 1975 at 19:36 CST, an earthquake of 7.5 and intensity (MMI) IX hit the city of Haicheng, Liaoning, China. Much of the city was evacuated before the earthquake, so few died from building collapse, however, many died from fire and hypothermia in the subsequent days. The evacuees lived during the deep winter in self-made tents made of tree branches, bed sheets, tarps and straw,Photos of such tents taken in 1976 can be found in: 372 froze to death and 6,578 suffered frostbite, while a fire burned 341 to death and 980 suffered non-fatal burns.颤抖的地球—地震科学' (2005). Researched by CEA 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. The fire was one of the most notable earthquake-induced fires in China, triggered from a combination of cooking, winter heating and lighting. The early evacuati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike-slip Fault
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] |
2007 Aysén Fjord Earthquake
7 (seven) is the natural number following 6 and preceding 8. It is the only prime number preceding a cube. As an early prime number in the series of positive integers, the number seven has greatly symbolic associations in religion, mythology, superstition and philosophy. The seven Classical planets resulted in seven being the number of days in a week. It is often considered lucky in Western culture and is often seen as highly symbolic. Unlike Western culture, in Vietnamese culture, the number seven is sometimes considered unlucky. It is the first natural number whose pronunciation contains more than one syllable. Evolution of the Arabic digit In the beginning, Indians wrote 7 more or less in one stroke as a curve that looks like an uppercase vertically inverted. The western Ghubar Arabs' main contribution was to make the longer line diagonal rather than straight, though they showed some tendencies to making the digit more rectilinear. The eastern Arabs developed the digit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aysén Region
The Aysén del General Carlos Ibáñez del Campo Region ( es, Región de Aysén, , '), often shortened to Aysén Region or Aisén,Examples of name usage1, official regional government site refers to the region as "Región de Aysén"., Chile's official meteorological agency refers to the region as "Región de Aisén".3 Chilean government official website refers of Pilar Cuevas Mardones as intendant of "Región de Aysén" .4 Chile's Ministry of Public Works calls the region "Región de Aysén" in the title of their 2011 report on that region.5, Corporación Nacional Forestal, a government agency refers to the region as "Región de Aysén" in their homepage. Here is some evidence of the short name use in English:I ''The Guardian'' reports on the 2012 Aysén protest.II ''Santiago Times'', a local English language newspaper use "Aysén Region" in a note referring to the same protest.III''Santiago Times'' again. *Vscientific paper in ''Journal of Hospital Infection'' referring to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2007 Peru Earthquake
The 2007 Peru earthquake, which measured 8.0 on the moment magnitude scale, hit the central coast of Peru on August 15 at 23:40:57 UTC (18:40:57 local time) and lasted two minutes. The epicenter was located south-southeast of Lima at a depth of . The United States Geological Survey National Earthquake Information Center reported that it was a ''Very strong'' earthquake. The Peruvian government stated that 519 people were killed by the quake. Earthquake This earthquake occurred at the boundary between the Nazca and South American tectonic plates, which are converging at a rate of per year. The earthquake occurred as thrust faulting on the interface between the two plates, with the South American Plate moving up and seaward over the Nazca Plate. Experts say this kind of earthquake is produced about once every 100 years. Coastal Peru has a history of very large earthquakes. The August 15th shock originated near the source of two previous earthquakes, both in the magnitude 8 rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru
, image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Firm and Happy for the Union" , national_anthem = "National Anthem of Peru" , march = "March of Flags" , image_map = PER orthographic.svg , map_caption = , image_map2 = , capital = Lima , coordinates = , largest_city = capital , official_languages = Peruvian Spanish, Spanish , languages_type = Co-official languages , languages = , ethnic_groups = , ethnic_groups_year = 2017 , demonym = Peruvians, Peruvian , government_type = Unitary state, Unitary Semi-presidential system, semi-presidential republic , leader_title1 = President of Peru, President ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arauco Province (historical)
Arauco Province ( es, Provincia de Arauco) is one of four provinces of the Chilean region of Bío Bío. It spans a coastal area of just south of the mouth of the Biobío River, the traditional demarcation between the nation's major natural regions, Zona Central and Zona Sur. The province originally covered the once-independent indigenous territory of Araucanía, but this was afterward divided into four provinces. It is devoted largely to agricultural pursuits. The capital Lebu (population 25,000) is situated on the coast about south of Concepción with which it is connected by rail. Administration As a province, Arauco is a second-level administrative division of Chile, governed by a provincial governor who is appointed by the president. Communes The province is composed of seven communes, each governed by a municipality consisting of an elected alcalde and municipal council. # Arauco # Cañete # Contulmo # Curanilahue # Lebu ''(provincial capital)'' # Los Álamos # ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ica Region
Ica (; qu, Ika) is a department and region of Peru. It borders the Pacific Ocean on the west; the Lima Region on the north; the Huancavelica and Ayacucho regions on the east; and the Arequipa Region on the south. Its capital is the city of Ica. Geography The Department of Ica has a remarkable geography. It is the only region of the southern coast formed by plains, also called coast plains, since the Andean Cordillera rise up inland. Some geological folds have determined the formation of dunes moving toward the sea, which form much of the Paracas Peninsula. Some isolated formations located at the southern part created the Marcona complex, with the biggest deposits of iron in the Pacific coast. Ica's configuration is due to the geomorphology of its two big and unique fluvial watersheds: the Pasco and Ica rivers. Also, it has a waterway called the Rio Grande, although its waters do not reach the ocean. Some waters are diverted for irrigation and agriculture in the provinces o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
