Earthquake
10106
225975339
2008-07-16T08:03:05Z
Alexdan loghin
2430331
/* 20th century */
{{pp-semi-vandalism|expiry=August 17, 2008|small=yes}}
{{Otheruses1|the natural seismic phenomenon}}
An '''earthquake''' is the result of a sudden release of energy in the [[Earth]]'s [[crust (geology)|crust]] that creates [[seismic wave]]s. Earthquakes are recorded with a [[seismometer]], also known as a seismograph. The [[Moment magnitude scale|moment magnitude ]] of an earthquake is conventionally reported, or the related and mostly obsolete [[Richter magnitude scale|Richter]] magnitude, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified [[Mercalli intensity scale|Mercalli scale]].
At the Earth's surface, earthquakes manifest themselves by a shaking and sometimes displacement of the ground. When a large earthquake [[epicenter]] is located offshore, the seabed sometimes suffers sufficient displacement to cause a [[tsunami]]. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word ''earthquake'' is used to describe any seismic event—whether a natural [[phenomenon]] or an event caused by humans—that generates [[seismic wave]]s. Earthquakes are caused mostly by rupture of geological faults, huge amounts of gas migration, mainly methane deep within the earth, but also by volcanic activity, landslides, mine blasts, and nuclear experiments.
An earthquake's point of initial rupture is called its [[focus (earthquake)|focus]] or [[hypocenter]]. The term [[epicenter]] means the point at ground level directly above this.
[[Image:Quake epicenters 1963-98.png|thumb|300px|Global earthquake [[epicenter]]s, 1963–1998]]
[[Image:Global plate motion 2008-04-17.jpg|thumb|300px|right|Global plate tectonic movement]]
==Naturally occurring earthquakes==
[[Image:Fault types.png|thumb|right|Fault types]]
Tectonic earthquakes will occur anywhere within the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a [[fault plane]]. In the case of [[Transform boundary|transform]] or [[Convergent boundary|convergent]] type plate boundaries, which form the largest fault surfaces on earth, they will move past each other smoothly and [[Aseismic creep|aseismically]] only if there are no irregularities or asperities along the boundary that increase the frictional resistance. Most boundaries do have such asperities and this leads to a form of [[Stick-slip phenomenon|stick-slip behaviour]]. Once the boundary has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the locked portion of the fault, releasing the stored energy. This energy is released as a combination of radiated elastic [[Strain (materials science)|strain]] [[seismic waves]], frictional heating of the fault surface, and cracking of the rock, thus causing an earthquake. This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the [[Elastic-rebound theory]]. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake [[Fracture (geology)|fracture]] growth or is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior.<ref name="USGS1">{{cite web | last = Spence | first = William | coauthors = S. A. Sipkin, G. L. Choy | title = Measuring the Size of an Earthquake | publisher = [[United States Geological Survey]] | date= 1989 | url = http://earthquake.usgs.gov/learning/topics/measure.php|accessdate = 2006-11-03 }}</ref>
===Earthquakes away from plate boundaries===
Where plate boundaries occur within continental lithosphere, deformation is spread out a over a much larger area than the plate boundary itself. In the case of the [[San Andreas fault]] continental transform, many earthquakes occur away from the plate boundary and are related to strains developed within the broader zone of deformation caused by major irregularities in the fault trace (e.g. the “Big bend” region). The [[Northridge earthquake]] was associated with movement on a blind thrust within such a zone. Another example is the strongly oblique convergent plate boundary between the [[Arabian plate|Arabian]] and [[Eurasian plate]]s where it runs through the northwestern part of the [[Zagros]] mountains. The deformation associated with this plate boundary is partitioned into nearly pure thrust sense movements perpendicular to the boundary over a wide zone to the southwest and nearly pure strike-slip motion along the Main Recent Fault close to the actual plate boundary itself. This is demonstrated by earthquake [[focal mechanism]]s. <ref> Talebian, M. Jackson, J. 2004. A reappraisal of earthquake focal mechanisms and active shortening in the Zagros mountains of Iran. Geophysical Journal International, 156, pages 506-526</ref>
All tectonic plates have internal stress fields caused by their interactions with neighbouring plates and sedimentary loading or unloading (e.g. deglaciation). These stresses may be sufficient to cause failure along existing fault planes, giving rise to [[intraplate earthquake]]s.
===Deep focus earthquakes===
The majority of tectonic earthquakes originate at depths not exceeding tens of kilometers. In [[Subduction|subduction zones]], where older and colder [[oceanic crust]] descends beneath another tectonic plate, [[Deep focus earthquake]]s may occur at much greater depths (up to seven hundred kilometers). These seismically active areas of subduction are known as [[Wadati-Benioff zone]]s. These are earthquakes that occur at a depth at which the subducted [[lithosphere]] should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep focus earthquakes is faulting caused by [[olivine]] undergoing a [[phase transition]] into a [[spinel]] structure.<ref name="olivine">{{cite journal
| last = Greene
| first = H. W.
| authorlink =
| coauthors = Burnley, P. C.
| title = A new self-organizing mechanism for deep-focus earthquakes
| journal = Nature
| volume = 341
| issue =
| pages = 733–737
| publisher =
| date = [[26 October]], [[1989]]
| url =
| doi = 10.1038/341733a0
| id =
| accessdate = }}</ref>
===Earthquakes and volcanic activity===
Earthquakes also often occur in volcanic regions and are caused there, both by tectonic faults and by the movement of [[magma]] in [[volcano]]es. Such earthquakes can serve as an early warning of volcanic eruptions.
===Earthquake clusters===
Most earthquakes form part of a sequence, related to each other in terms of location and time.
====Aftershocks====
{{Main|Aftershocks}}
In a sequence of earthquakes there is normally one event significantly larger than the other that is referred to as the ''main shock'', any earthquakes before that are termed ''foreshocks'', with those occurring later are termed ''aftershocks''.
====Earthquake swarms====
{{Main|Earthquake swarm}}
If there is no earthquake that is clearly the main shock, a sequence of related shocks is referred to as an earthquake swarm.
====Earthquake storms====
{{Main|Earthquake storm}}
Sometimes a series of earthquakes occur in a sort of [[earthquake storm]], where the earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to [[aftershock]]s but on adjacent segments of fault, these storms occur over the course of years, and with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the [[North Anatolian Fault]] in Turkey in the 20th century and has been inferred for older anomalous clusters of large earthquakes in the Middle East<ref>{{cite journal | title = Poseidon’s Horses: Plate Tectonics and Earthquake Storms in the Late Bronze Age Aegean and Eastern Mediterranean | journal = [[Journal of Archaeological Science]] | year = 2000 | author = Amos Nur | issn = 0305-4403 | volume = 27 | pages = 43–63 | url = http://water.stanford.edu/nur/EndBronzeage.pdf | doi = 10.1006/jasc.1999.0431 }}</ref>.
==Size and frequency of occurrence==
{{geographical imbalance|a region|article}}
Minor earthquakes occur nearly constantly around the world in places like [[California]] and [[Alaska]] in the U.S., as well as in [[Chile]], [[Peru]], [[Indonesia]], [[Iran]], [[Pakistan]] the [[Azores]] in [[Portugal]], [[Turkey]], [[New Zealand]], [[Greece]], [[Italy]], and [[Japan]], but earthquakes can occur almost anywhere, including [[New York City]], [[London]], and [[Australia]].<ref>
{{cite web
| url=http://earthquake.usgs.gov/
| title=Earthquake Hazards Program
| publisher=[[USGS]]
| accessdate=2006-08-14
}}</ref> Larger earthquakes occur less frequently, the relationship being [[Gutenberg-Richter law|exponential]]; for example, roughly ten times as many earthquakes larger than magnitude 4 occur in a particular time period than earthquakes larger than magnitude 5. In the (low seismicity) [[United Kingdom]], for example, it has been calculated that the average recurrences are:
*an earthquake of 3.7 - 4.6 every year
*an earthquake of 4.7 - 5.5 every 10 years
*an earthquake of 5.6 or larger every 100 years.
The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past, but this is because of the vast improvement in instrumentation, rather than an increase in the number of earthquakes. The [[USGS]] estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0-7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable.<ref>
{{cite web
| title=Common Myths about Earthquakes
| url=http://earthquake.usgs.gov/learning/faq.php?categoryID=6&faqID=110
| publisher=[[USGS]]
| accessdate=2006-08-14
}}</ref> In recent years, the number of major earthquakes per year has decreased, although this is thought likely to be a [[statistical fluctuation]] rather than a systematic trend. More detailed statistics on the size and frequency of earthquakes is available from the USGS.<ref>
{{cite web
| title=Earthquake Facts and Statistics: Are earthquakes increasing?
| url=http://neic.usgs.gov/neis/eqlists/eqstats.html
| publisher=[[USGS]]
| accessdate=2006-08-14
}}</ref>
Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-km-long, horseshoe-shaped zone called the '''[[Pacific Ring of Fire|circum-Pacific seismic belt]]''', also known as the [[Pacific Ring of Fire]], which for the most part bounds the [[Pacific Plate]].<ref>
{{cite web
| title=Historic Earthquakes and Earthquake Statistics: Where do earthquakes occur?
| url=http://earthquake.usgs.gov/learning/faq.php?categoryID=11&faqID=95
| publisher=[[USGS]]
| accessdate=2006-08-14
}}</ref><ref>
{{cite web
| url=http://earthquake.usgs.gov/learning/glossary.php?termID=150
| title=Visual Glossary - Ring of Fire
| accessdate=2006-08-14
}}</ref> Massive earthquakes tend to occur along other plate boundaries, too, such as along the [[Himalayan Mountains]]. Humans can cause earthquakes for example by constructing large [[dam]]s and [[building]]s, drilling and injecting liquid into [[water well|well]]s, and by [[coal mining]] and [[oil well|oil drilling]].<ref>{{cite news|author=Madrigal, Alexis|title=Top 5 Ways to Cause a Man-Made Earthquake|url=http://blog.wired.com/wiredscience/2008/06/top-5-ways-that.html|date=[[June 4]], [[2008]]|work=Wired News|publisher=CondéNet|accessdate=2008-06-05}}</ref>
With the rapid growth of [[Megacity|mega-cities]] such as [[Mexico City]], [[Tokyo]] or [[Tehran]], in areas of high seismic risk, some seismologists are warning that a single quake may claim the lives of up to 3 million people.<ref>[http://www.nhm.ac.uk/nature-online/environmental-change/asl-2005/html-version/earthquake/earthquake-future.html Catastrophic earthquake]</ref><ref>[http://cires.colorado.edu/~bilham/UrbanEarthquakesGlobal.html Global urban seismic risk]</ref><ref>[http://www.iranian.ws/iran_news/publish/article_23761.shtml Earthquake safety in Iran and other developing countries]</ref>
==Effects/impacts of earthquakes==
{{FixBunching|beg}}
[[Image:1755 Lisbon earthquake.jpg|thumb|200px|1755 copper engraving depicting [[Lisbon]] in ruins and in flames after the [[1755 Lisbon earthquake]]. A [[tsunami]] overwhelms the ships in the harbor.]]
{{FixBunching|mid}}
[[Image:Sanfranciscoearthquake1906.jpg|thumb|200px|Right|Smoldering after the [[1906 San Francisco earthquake]].]]
{{FixBunching|mid}}
[[Image:AlaskaQuake-FourthAve.jpg|thumb|200px|Earthquake damage in [[Anchorage]], [[Alaska]] (1964).]]
{{FixBunching|mid}}
[[Image:Tlatelolco.PNG|thumb|200px|Earthquake damage in [[Mexico City]] (1985).]]
{{FixBunching|mid}}
[[Image:Spitakear.jpg|right|thumb|200px|Earthquake damage in [[Armenia]] (1988).]]
{{FixBunching|mid}}
[[Image:Cypress structure.jpeg|thumb|200px|Right|A section of the Cypress viaduct collapsed during the [[Loma Prieta Earthquake]] (1989).]]
{{FixBunching|mid}}
[[Image:Kaiser Permanente Building After Northridge Earthquake.jpg|thumb|200px|Kaiser Permanente Building destroyed in the [[Northridge Earthquake]] (1994).]]
{{FixBunching|mid}}
[[Image:阪神淡路大震災343.jpg|thumb|200px|Damage in [[Great Hanshin earthquake]] (1995) in [[Kobe]], Japan.]]
{{FixBunching|mid}}
[[Image:Chuetsu earthquake-earthquake liquefaction1.jpg|thumb|200px|Right|[[2004 Chūetsu earthquake|Chūetsu earthquake]] (2004).]]
{{FixBunching|end}}
{{Expand-section|date=December 2007}}
There are many effects of earthquakes including, but not limited to the following:
=== Shaking and ground rupture===
Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings or other rigid structures. The severity of the local effects depends on the complex combination of the earthquake [[Richter magnitude scale|magnitude]], the distance from [[epicenter]], and the local geological and geomorphological conditions, which may amplify or reduce [[wave propagation]]<ref>[http://www.abag.ca.gov/bayarea/eqmaps/doc/contents.html On Shaky Ground, Association of Bay Area Governments, San Francisco, reports 1995,1998 (updated 2003)]</ref>. The ground-shaking is measured by ground [[acceleration]].
Specific local geological, geomorphological, and geostructural features can induce high levels of shaking on the ground surface even from low-intensity earthquakes. This effect is called site or local amplification. It is principally due to the transfer of the [[seismic]] motion from hard deep soils to soft superficial soils and to effects of seismic energy focalization owing to typical geometrical setting of the deposits.
Ground rupture is a visible breaking and displacement of the earth's surface along the trace of the fault, which may be of the order of few metres in the case of major earthquakes. Ground rupture is a major risk for large engineering structures such as [[dams]], [[bridges]] and [[nuclear power stations]] and requires careful mapping of existing faults to identify any likely to break the ground surface within the life of the structure<ref>[http://www.consrv.ca.gov/cgs/information/publications/cgs_notes/note_49/Documents/note_49.pdf Guidelines for evaluating the hazard of surface fault rupture, California Geological Survey]</ref>.
===Landslides and avalanches===
Earthquakes can cause [[landslide]]s and [[avalanche]]s, which may cause damage in hilly and mountainous areas.
===Fires===
Following an earthquake, [[fire]]s can be generated by break of the [[electric power|electrical power]] or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has started.
===Soil liquefaction===
[[Soil liquefaction]] occurs when, because of the shaking, water-saturated [[granular]] material temporarily loses its strength and transforms from a [[solid]] to a [[liquid]]. Soil liquefaction may cause rigid structures, as buildings or bridges, to tilt or sink into the liquefied deposits.
=== Tsunami ===
Undersea earthquakes and earthquake-triggered landslides into the sea, can cause [[Tsunami]]. See, for example, the [[2004 Indian Ocean earthquake]].
=== Floods ===
Floods may be a secondary effects of earthquakes, if dams are damaged.
Earthquakes may cause landslips to dam rivers, which then collapse and cause floods.
===Human impacts===
Earthquakes may result in [[disease]], lack of basic necessities, loss of life, higher insurance premiums, general property damage, road and bridge damage, and collapse of buildings or destabilization of the base of buildings which may lead to collapse in future earthquakes.
The most significant human impact is loss of life
==Preparation for earthquakes==
*[[Earthquake preparedness]]
*[[Household seismic safety]]
*[[HurriQuake]] nail (for resisting hurricanes and earthquakes)
*[[Seismic retrofit]]
*[[Seismic hazard]]
*[[Mitigation of seismic motion]]
*[[Earthquake prediction]]
==Well-known faults==
<div style="-moz-column-count:3; column-count:3;">
*[[Alpine Fault]]
*[[Calaveras Fault]]
*[[Cascadia subduction zone]]
*[[Geology of the Death Valley area]]
*[[Great Sumatran fault]]
*[[Hayward Fault Zone]]
*[[Hope Fault]]
*[[Liquiñe-Ofqui Fault]]
*[[North Anatolian Fault Zone]]
*[[New Madrid Fault Zone]]
*[[San Andreas Fault]]
*[[Wasatch Fault]]
</div>
==Major earthquakes==
{{Main|List of earthquakes}}
===Pre-20th century===
*[[Pompeii]] (62 AD).
*[[1138 Aleppo earthquake|Aleppo Earthquake]] (1138).
*[[Basel earthquake]] (1356). Major earthquake that struck Central Europe in 1356.
*[[Carniola]] earthquake (1511). A major earthquake that shook a large portion of South-[[Central Europe]]. Its epicenter was around the town of [[Idrija]], in today's [[Slovenia]]. It caused great damage to structures all over [[Carniola]], including [[Ljubljana]], and in western [[Duchy of Carinthia|Carinthia]], particularly in [[Villach]] and [[Klagenfurt]] which were almost completely destroyed. There was some minor damage in [[Venice]] and other cities, too.
*[[Shaanxi Earthquake]] (1556). Deadliest known earthquake in history, estimated to have killed 830,000 in [[China]].
*[[Dover Straits earthquake of 1580|Dover Straits]] (1580).
*[[Dubrovnik earthquake]] (1667). Disastrous earthquake in [[Dubrovnik]], [[Croatia]] killed about 3/5 of the population.
*[[Port Royal]] Earthquake (1692). An earthquake on [[June 7]], [[1692]], largely destroyed [[Port Royal]], a safe harbor for [[pirates]], causing two thirds of the city to sink into the [[Caribbean Sea]].
*[[Sicilian Baroque#Earthquake and patrons|The great Sicilian earthquake]] (1693). As many as 100,000 may have died.
*[[Cascadia Earthquake]] (1700).
*[[Tokyo]] earthquake (1703). 37,000 died.
*[[Kamchatka earthquakes]] (1737) The third biggest earthquake on record measuring 9.3 on the Richter scale.
*[[1755 Lisbon earthquake|Lisbon earthquake]] (1755), one of the most destructive and deadly earthquakes in history, killing between 60,000 and 100,000 people and causing a major [[tsunami]] that affected parts of [[Europe]], [[North Africa]] and the [[Caribbean]].
*[[Calabria earthquake]] (1783). Series of 6 earthquakes in [[Calabria]], [[Italy]] killed 50,000.<ref>[http://www.infoplease.com/ipa/A0001439.html Earthquakes and Volcanic Eruptions]</ref>
*[[Quito]] earthquake. (1797) [[Quito]], [[Viceroyalty of Peru]], now the capital of [[Ecuador]], was devastated by an earthquake. 40,000 died.
*[[New Madrid Earthquake]] (1811), and another tremor (1812) that also struck the small Missouri town, was reportedly the strongest ever in [[North America]] and made the [[Mississippi River]] temporarily change its direction and permanently altered its course in the region.
*[[Fort Tejon earthquake|Fort Tejon Earthquake]] (1857). Estimated Richter Scale above 8, said the strongest earthquake in Southern California history.
*[[Great Neapolitan Earthquake]] (1857). Estimated Richter Scale of 6.9. 11,000 dead.
*[[1872 Lone Pine earthquake]] (1872). Might been strongest ever measured in California with an estimated Richter Scale of 8.1 said [[seismologists]].
*[[Charleston earthquake]] (1886). Largest earthquake in the southeastern United States, killed 100.
*[[Ljubljana earthquake]] (14. IV. 1895), a series of powerful quakes that ultimately had a vital impact on the city of [[Ljubljana]], being a [[catalyst]] of its urban renewal.
*[[Assam earthquake of 1897]] (1897). Large earthquake that destroyed all masonry structures, measuring more than 8 on the Richter scale.
===20th century===
*[[1906 San Francisco Earthquake|San Francisco Earthquake]] (1906). Between 7.7 and 8.3 magnitudes; killed approximately 3,000 people and caused around $400 million in damage; most devastating earthquake in California and U.S. history.
*[[Messina Earthquake]] (1908). Killed about 60,000 people.
* [[Gansu earthquake]] (1920). Killed 200,000 in [[Gansu#History|Gansu]] province, [[China]].<ref>[http://library.thinkquest.org/TQ0311162/1920.htm Earthquake Timeline - 1920]</ref>
*[[1923 Great Kanto earthquake|Great Kantō earthquake]] (1923). On the Japanese island of [[Honshū]], killing over 140,000 in [[Tokyo]] and environs.
*[[1931 Hawke's Bay earthquake]]. Occurred in the [[Hawkes Bay]] in the [[North Island]] of [[New Zealand]] leaving 256 dead.
*[[1933 Long Beach earthquake]]
*[[1935 Balochistan earthquake]] at Quetta, Pakistan measuring 7.7 on the Richter scale. Anywhere from 30,000 to 60,000 people died
*[[1939 Erzincan earthquake]] at [[Erzincan]], [[Turkey]] measuring 7.9 on the Richter scale.
*[[Ashgabat earthquake]] (1948). Earthquake in [[Ashgabat]], [[Soviet Union]] measuring 7.3 on the Richter scale killed over 110,000 (2/3 the population of the city).<ref>[http://www.cbc.ca/news/background/forcesofnature/natural-disasters.html World's worst natural disasters since 1900]</ref>
*[[Assam earthquake of 1950]] (1950). Earthquake in [[Assam]], India measures 8.6M.
*[[Kamchatka earthquakes]] (1952 and 1737), measuring >9.0.
*Great [[Kern County earthquake]] (1952). This was second strongest tremor in Southern California history, epicentered 60 miles North of Los Angeles. Major damage in [[Bakersfield, California]] and [[Kern County, California]], while it shook the Los Angeles area.
*[[1959 Yellowstone earthquake]], formed [[Quake Lake]] in southern Montana, USA
*[[Great Chilean Earthquake]] (1960). Strongest earthquake ever recorded,<ref name = "nqqkwd">[http://earthquake.usgs.gov/regional/world/10_largest_world.php Largest Earthquakes in the World Since 1900<!-- Bot generated title -->]</ref> 9.5 on Moment magnitude scale, and generated [[tsunami]]s throughout the Pacific ocean. It measured 9.6 on the [[Richter scale]]. <ref> Koffee News. (Avon, NJ: Koffee News, 2008)Vol 1, No. 41. p. 1. </ref>
*[[1960 Agadir earthquake]], [[Morocco]] with around 15,000 casualties.
*[[1963 Skopje earthquake]], measuring 6.1 on the Richter scale kills 1,800 people, leaves another 120,000 homeless, and destroys 80% of the city.
*[[Good Friday Earthquake]] (1964) In Alaska, it was the fourth biggest earthquake recorded,<ref name = "nqqkwd"/> measuring 9.2M. and generated tsunamis throughout the Pacific ocean.
*[[1966 Tashkent Earthquake]]. Ruined most of [[Tashkent]], [[Uzbek SSR]], [[USSR]] (now [[Uzbekistan]]), tens of thousands of deaths.
*[[1970 Ancash earthquake|Ancash earthquake]] (1970). Caused a [[landslide]] that buried the town of [[Yungay, Peru]]; killed over 40,000 people.
*[[Sylmar earthquake]] (1971). Caused great and unexpected destruction of freeway bridges and flyways in the [[San Fernando Valley]], leading to the first major [[seismic retrofit]]s of these types of structures, but not at a sufficient pace to avoid the next California freeway collapse in 1989.
*[[1972 Nicaragua earthquake|Managua earthquake (1972)]], which killed more than 10,000 people and destroyed 90% of the city. The earthquake took place on [[December 23]], [[1972]] at midnight.
*[[Friuli]] earthquake (1976), Which killed more than 2,000 people in Northeastern [[Italy]] and in the [[Slovenian Littoral]] on the 6th of May
*[[1976 Tangshan earthquake|Tangshan earthquake]] (1976). The most destructive earthquake of modern times. The official death toll was 255,000, but many experts believe that two or three times that number died.
*[[Guatemala]] [[Guatemala 1976 earthquake|1976 earthquake]] (1976). Causing 23,000 deaths, 77,000 injuries and the destruction of more than 250,000 homes.
*[[1977 Bucharest earthquake|Vrancea, Romania earthquake]] (1977). 7.2-7.4 on the Richter scale. Over 1500 people killed, the majority in the Romanian capital Bucharest.
*[[Coalinga, California earthquake]] (1983). 6.5 on the Richter scale on a section of the San Andreas Fault. Six people killed, downtown [[Coalinga, California]] devastated and oil field blazes.
*[[1985 Mexico City earthquake|Great Mexican Earthquake]] (1985). Killed over 6,500 people, according to official Mexican government reports,{{Fact|date=December 2007}} but as many as 30,000 people are thought to have been killed (they disappeared and never reappeared after the initial Earthquakes).
*[[Great San Salvador Earthquake]] ([[October 10]], [[1986]]). Killed over 1,500 people.
*[[Whittier Narrows earthquake]] (1987).
*[[1989 Newcastle earthquake]], Australia
*[[Leninakan Earthquake|Armenian earthquake]] (1988). Killed over 25,000.
*[[Loma Prieta earthquake]] (1989). Severely affecting [[Santa Cruz, California|Santa Cruz]], [[San Francisco]], [[San Jose, California|San Jose]] and [[Oakland, California|Oakland]] in [[California]]. This is also called the [[World Series]] Earthquake. It struck as Game 3 of the [[1989 World Series]] was just getting underway at [[Candlestick Park]] in [[San Francisco]]. Revealed necessity of accelerated seismic retrofit of road and bridge structures.
*[[1990 Iran earthquake|Iran Earthquake]] (1990). 7.7 on the Richter scale. Killed over 35,000 in [[Gilan Province]], southwest of [[Caspian sea]].<ref>[http://news.bbc.co.uk/2/hi/middle_east/3348613.stm Iran earthquake kills thousands]</ref>
*[[1990 Luzon earthquake|Luzon Earthquake]] (1990). On [[16 July]] [[1990]], an earthquake measuring 7.7 on the Richter scale struck the island of [[Luzon, Philippines]].
*[[Landers, California earthquake]] (1992). Serious damage in the small town of [[Yucca Valley, California]] and was felt across 10 states in Western U.S. Another tremor measured 6.4 struck 3 hours later and felt across Southern California.
*[[August 1993]] Guam Earthquake, measuring 8.2 on the Richter scale and lasting 60 seconds.
*[[1993 Latur earthquake]] Latur Earthquake,an earthquake of magnitude 6.3 on Richter Scale rocked the districts of Latur and Osmanabad in [[Maharashtra]] in [[India]].The degree of fury was such that dwellings in several villages of these 2 districts were totally converted to debris. In adjoining [[Karnataka]] state, 9 people were killed and about 16,000 people injured. A huge number of houses were damaged.<ref>[http://en.wikipedia.org/wiki/Killari]</ref>
*[[1994 Northridge Earthquake|Northridge, California earthquake]] (1994). Damage showed seismic resistance deficiencies in modern low-rise apartment construction.
*[[Neftegorsk, Sakhalin Oblast|Sakhalin earthquake]] (1995). Measuring 7.6 on the Richter scale, killing over 2,000 people in [[Sakhalin]], [[Russia]].<ref>[http://pdm.medicine.wisc.edu/johnson.htm The Tale of the Tragedy of Neftegorsk]</ref>
*[[Great Hanshin earthquake]] (1995). Killed over 6,400 people in and around [[Kobe]], [[Japan]].
*1998 Afghanistan earthquake (1998). 6.9 on the Richter scale. Some 125 villages were damaged and 4000 people killed.<ref>[http://news.bbc.co.uk/onthisday/hi/dates/stories/february/4/newsid_2534000/2534279.stm 1998: 4,000 feared dead in Afghan earthquake]</ref>
*[[Athens earthquake]] (1999). 5.9 on the Richter scale, it hit [[Athens]] on [[September 7]]. Epicentered 10 miles north of the Greek capital, it claimed 143 lives.
*[[Chi-Chi earthquake]] (1999) Also called the 921 earthquake. Struck [[Taiwan]] on [[September 21]], [[1999]]. Over 2,000 people killed, destroyed or damaged over ten thousand buildings. Caused world computer prices to rise sharply.
*[[Armenia, Colombia]] (1999) 6.2 on the Richter scale, Killed over 2,000 in the Colombian Coffee Grown Zone.
*1999 [[1999 İzmit earthquake|İzmit earthquake]] measuring 7.5 on the Richter scale and killed over 40,000 people and left approximately half a million people homeless in northwestern [[Turkey]].
*[[Hector Mine|Hector Mine earthquake]] (1999). 7.1 on the Richter scale, epicentered 30 miles east of [[Barstow, California]], widely felt in California and [[Nevada]].
*1999 [[Düzce earthquake]] at [[Düzce]], [[Turkey]] measuring 7.2 on the Richter scale.
*[[2000 Baku earthquake|Baku earthquake]] (2000).
===21st century===
*[[Nisqually Earthquake]] (2001).
*[[2001 El Salvador earthquakes|El Salvador earthquakes]] (2001). 7.9 ([[13 January]]) and 6.6 ([[13 February]]) magnitudes, killed more than 1,100 people.
*[[2001 Gujarat Earthquake|Gujarat Earthquake]] ([[26 January]] [[2001]]).
*[[2002 Hindu Kush earthquakes|Hindu Kush earthquakes]] (2002). Over 1,100 killed.
*[[2002 Molise earthquake|Molise earthquake]] (2002) 26 killed.
*[[Bam, Iran#2003 earthquake|Bam Earthquake]] (2003). Over 40,000 people are reported dead.
*[[Parkfield earthquake|Parkfield, California earthquake]] (2004). Not large (6.0), but the most anticipated and intensely instrumented earthquake ever recorded and likely to offer insights into predicting future earthquakes elsewhere on similar slip-strike fault structures.
*[[2004 Chūetsu earthquake|Chūetsu earthquake]] (2004).
*[[2004 Indian Ocean earthquake|Sumatra-Andaman Earthquake]] (26 December 2004). By some estimates, the second largest earthquake in recorded history (estimates of magnitude vary between 9.1<ref name = "nqqkwd"/> and 9.3). Epicentered off the coast of the [[Indonesia]]n island of [[Sumatra]], this massive earthquake triggered a series of gigantic [[tsunami]]s that smashed onto the shores of a number of nations, causing 230,000 fatalities.
*[[2005 Sumatra earthquake|Sumatran (Nias) Earthquake]] (2005).
*[[2005 Fukuoka earthquake|Fukuoka earthquake]] (2005).
*[[Northern Chile Earthquake]] (2005). 7.9 ([[13 June]]). Killed only 15 people, but left many poor families homeless.{{fact}}
*[[2005 Kashmir earthquake|Kashmir earthquake]] (2005) (also known as the Great Pakistan earthquake). Killed over 79,000 people; and many more injured.
*[[2005 Lake Tanganyika earthquake|Lake Tanganyika earthquake]] (2005).
*[[May 2006 Java earthquake]] (2006).
*[[July 2006 Java earthquake|July 2006 7.7 magnitude Java earthquake]] which triggered [[tsunami]]s (2006).
*[[2006 Hawaii earthquake|October 2006 6.6 magnitude Kona, Hawaii earthquake]] (2006).
*[[2006 Kuril Islands earthquake|November 2006 8.1 magnitude north of Japan]] (2006).
*[[2006 Hengchun earthquake|December 26, 2006, 7.2 magnitude, southwest of Taiwan]] (2006).
*[[March 2007 Sumatra earthquakes|Sumatra Earthquakes March 06, 2007, 6.4 and 6.3 magnitude, Sumatra, Indonesia]] (2007).
*[[2007 Noto earthquake|March 25, 2007, 6.9 magnitude, off the west coast of Honshū, Japan]] (2007).
*[[2007 Solomon Islands earthquake|April 1, 2007, 8.1 magnitude, Solomon Islands]] (2007).
*[[2007 Guatemala Earthquake]] 6.7 magnitude (2007).
*[[2007 Niigata earthquake|July 16, 2007, 6.6 magnitude, Niigata prefecture, Japan]] (2007).
*[[2007 Peru earthquake]] 8.0 magnitude, August 15 (2007)<ref name="ECPE">{{cite web | first =
El Comercio Peru | title = El Comercio Peru | url = http://www.elcomercio.com.pe/ediciononline/HTML/olecportada/2007-08-15/olecportada0419459.html}}</ref>
*[[September 2007 Sumatra earthquakes]] 8.0 magnitude September 12 (2007)<ref>[http://www.channelnewsasia.com/stories/afp_asiapacific/view/299424/1/.html Channelnewsasia.com<!-- Bot generated title -->]</ref>
*[[2007 Antofagasta earthquake|November 14, 2007, 7.7 magnitude, Antofagasta, Chile]] (2007).
*[[November 2007 Caribbean Sea earthquake|November 29, 2007, 7.4 magnitude, Caribbean Sea]] (2007).{{fact}}
*[[2007 Gisborne earthquake|December 20, 2007 6.8 magnitude, Gisborne, New Zealand]] (2007).
*[[February 20]] [[2008]] [[Sumatra]] earthquake 7.5 magnitude<ref>www.4chan.org</ref>
*[[February 25]] [[2008]] [[Sumatra]] earthquake 7.3 magnitude. The quake was centered about 160 km (100 miles) south-southwest of [[Padang]]. The [[Pacific Tsunami Warning Center]] issued a local [[tsunami]] watch.<ref>[http://edition.cnn.com/2008/WORLD/asiapcf/02/25/indonesia.quake/index.html cnn.com]</ref>
*[[March 21]] [[2008]] [[China]] earthquake 7.2 magnitude. The quake happened in [[Yutian County, Xinjiang]], a remote region in the [[Kunlun Mountains]] far from any residential areas.<ref>[http://edition.cnn.com/2008/WORLD/asiapcf/03/20/china.quake/index.html cnn.com]</ref>
*[[March 29]] [[2008]] [[Sumatra]] earthquake 6.3 magnitude. The epicenter was about 175 miles (281 kilometers) south of [[Banda Aceh]] -- in a region hard-hit by the [[2004 Indian Ocean earthquake]]. The [[Pacific Tsunami Warning Center]] issued warnings on the possibility of the quake triggering [[tsunami]]s on coasts near its epicenter.<ref>[http://edition.cnn.com/2008/WORLD/asiapcf/03/29/indonesia.quake/index.html Quake in Indonesia raises tsunami fears]</ref>
*[[April 8]] [[2008]] earthquake 7.5 magnitude. The quake was in the southern [[Pacific Ocean]], about 85 kilometers southwest of [[Vanuatu]].
*[[May 12]] [[2008]] [[2008 Sichuan earthquake|earthquake 8.0 magnitude]] about 60 kilometers northwest of [[Chengdu]] in the [[Sichuan]] province in [[China]], killed over 65,000 people, expected to soar and [[China]] admits quake death toll could exceed 80,000.
==Earthquakes in mythology and religion==
In [[Norse mythology]], earthquakes were explained as the violent struggling of the god [[Loki]]. When Loki, [[Aesir|god]] of mischief and strife, murdered [[Baldr]], god of beauty and light, he was punished by being bound in a cave with a poisonous serpent placed above his head dripping venom. Loki's wife [[Sigyn]] stood by him with a bowl to catch the poison, but whenever she had to empty the bowl the poison would drip on Loki's face, forcing him to jerk his head away and thrash against his bonds, causing the earth to tremble.<ref>[[Prose Edda]] by [[Snorri Sturluson]]</ref>
In [[Greek mythology]], [[Poseidon]] was the god of earthquakes.<ref>[http://www.theoi.com/Olympios/Poseidon.html POSEIDON : Greek god of the sea & earthquakes ; mythology ; pictures : NEPTUNE<!-- Bot generated title -->]</ref>
==See also==
{{wiktionarypar|earthquake}}
<div style="-moz-column-count:2; column-count:2;">
*[[Catastrophe modeling]]
*[[Cryoseism]]
*[[Earthquake insurance]]
*[[Earthquake light]]s
*[[Earthquake engineering]]
*[[Earthquake weather]]
*''[[Earthquake (film)|Earthquake (1974 disaster film)]]''
*[[Geophysics]]
*[[Disaster#Causes of hypothetical future disasters|Hypothetical future disasters]]
*[[Interplate earthquake]]
*[[Japan Meteorological Agency seismic intensity scale]]
*[[List of earthquakes]]
*[[List of deadly earthquakes since 1900|List of all deadly earthquakes since 1900]]
*[[List of natural disasters by death toll#Earthquakes|List of earthquakes by death toll]]
*[[List of tectonic plates]]
*[[Megathrust earthquake]]
*[[Meizoseismal area]]
*[[Moonquake]]
*[[Plate tectonics]]
*[[Seismic scale]]
*[[Seismogenic layer]]
*[[Seismology]]
*[[Slow earthquake]]
*[[Shock (mechanics)]]
*[[Submarine earthquake]]
*[[Supershear earthquake]]
*The [[VAN method]]
</div>
==References==
{{Reflist|2}}
== External links ==
{{commons|Earthquake}}
===Educational===
*{{HSW|12-of-the-most-destructive-earthquakes|12 of the Most Destructive Earthquakes}}
* [http://www.edu4hazards.org/earthquake.html How to survive an earthquake - Guide for children and youth]
*[http://www.geo-world.org/earthquake Guide to earthquakes and plate tectonics]
*[http://pubs.usgs.gov/gip/earthq1/ ''Earthquakes''] — an educational booklet by Kaye M. Shedlock & Louis C. Pakiser
*[http://pubs.usgs.gov/gip/earthq4/severitygip.html The Severity of an Earthquake]
*[http://earthquake.usgs.gov/faq/ USGS Earthquake FAQs]
*[http://www.iris.edu/seismon/ IRIS Seismic Monitor] - maps all earthquakes in the past five years.
*[http://earthquake.usgs.gov/eqcenter/recenteqsww/ Latest Earthquakes in the World] - maps all earthquakes in the past week.
*[http://www.whoi.edu/page.do?pid=12460 Earthquake Information from the Deep Ocean Exploration Institute], [[Woods Hole Oceanographic Institution]]
*[http://www.geo.mtu.edu/UPSeis/locating.html Geo.Mtu.Edu] — How to locate an earthquake's epicenter
*[http://nisee.berkeley.edu/elibrary/browse/kozak?eq=5234 Photos/images of historic earthquakes]
*[http://www.earthquakecountry.info/ earthquakecountry.info] Answers to FAQs about Earthquakes and Earthquake Preparedness
*[http://www.guardian.co.uk/flash/0,5860,1121610,00.html Interactive guide: Earthquakes] - an educational presentation by [[Guardian Unlimited]]
*[http://geowall.geo.lsa.umich.edu/visualization.html Geowall] — an educational 3D presentation system for looking at and understanding earthquake data
*[http://www.sciencecourseware.com/VirtualEarthquake/ Virtual Earthquake] - educational site explaining how epicenters are located and magnitude is determined
*[http://science.howstuffworks.com/earthquake.htm HowStuffWorks — How Earthquakes Work]
*[http://archives.cbc.ca/IDD-1-75-1561/science_technology/earthquakes_and_tsunamis/ CBC Digital Archives — Canada's Earthquakes and Tsunamis]
*[http://www.dmoz.org/Science/Earth_Sciences/Geophysics/Earthquakes/ Earthquakes Educational Resources - dmoz]
===Seismological data centers===
====Europe====
*[http://www.isc.ac.uk/ International Seismological Centre (ISC)]
*[http://www.emsc-csem.org/ European-Mediterranean Seismological Centre (EMSC)]
*[http://www.gfz-potsdam.de/geofon/seismon/globmon.html Global Seismic Monitor at GFZ Potsdam]
*[http://tsunami.geo.ed.ac.uk/local-bin/quakes/mapscript/demo_run.pl Global Earthquake Report – chart]
*[http://hraun.vedur.is/ja/englishweb/index.html Earthquakes in Iceland during the last 48 hours]
*[http://www.ingv.it Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy]
*[http://www.ingv.it/DISS/ Database of Individual Seismogenic Sources (DISS), Central Mediterranean]
*[http://www.meteo.pt/opencms/im/en/sismologia/sismObservGeral.jsp Portuguese Meteorological Institute (Seismic activity during the last month)]
====Japan====
*[http://www.jma.go.jp/en/quake/ Earthquake Information of Japan, Japan Meteorological Agency]
*[http://iisee.kenken.go.jp/ International Institute of Seismology and Earthquake Engineering (IISEE)]
*[http://www.kenken.go.jp/english/index.html Building Research Institute]
*[http://iisee.kenken.go.jp/utsu/ Database for the damage of world earthquake, ancient period (3000 BC) to year of 2006]- Building Research Institute (Japan) ([[:ja:建築研究所|建築研究所]]) in Japanese
*[http://weathernews.jp/quake/ Weathernews Inc.(Seismic activity during the last 7 days)], in Japanese language.
**[http://weathernews.com/wpfglobal.xbap Weathernews Inc Global web site]
====United States====
*[http://www.eqnet.org/ EQNET: Earthquake Information Network]
*[http://neic.usgs.gov/ The U.S. National Earthquake Information Center]
*[http://www.data.scec.org/ Southern California Earthquake Data Center]
*[http://www.scec.org The Southern California Earthquake Center (SCEC)]
*[http://www.earthquakecountry.info/roots/ Putting Down Roots in Earthquake Country] An Earthquake Science and Preparedness Handbook produced by SCEC
*[http://www.data.scec.org/recenteqs/Quakes/quakes0.html Recent earthquakes in California and Nevada ]
*[http://rev.seis.sc.edu Seismograms for recent earthquakes via REV, the Rapid Earthquake Viewer]
*[http://www.iris.edu Incorporated Research Institutions for Seismology (IRIS)], earthquake database and software
*[http://www.iris.edu/seismon/ IRIS Seismic Monitor] - world map of recent earthquakes
*[http://www.iris.edu/seismo/ SeismoArchives] - seismogram archives of significant earthquakes of the world
===Seismic scales===
*[http://www.gfz-potsdam.de/pb5/pb53/projekt/ems/ The European Macroseismic Scale]
===Scientific information===
* {{cite web
| url=http://simscience.org/crackling/Advanced/Earthquakes/GutenbergRichter.html
| title=Earthquake Magnitudes and the Gutenberg-Richter Law
| publisher=[http://simscience.org/index.html SimScience]
| accessdate=2006-08-14
}}
* {{cite journal
| author=Hiroo Kanamori, Emily E. Brodsky
| title=The Physics of Earthquakes
| journal=Physics Today
| year=2001
| month=June
| volume=54
| issue=6
| pages=34
| url=http://www.physicstoday.org/pt/vol-54/iss-6/p34.html
| doi=10.1063/1.1387590
}}
===Miscellaneous===
*[http://www.china-quake.com/ Reports on China Sichuan earthquake 12/05/2008]
*[http://www.kashmirearthquake.com/ Kashmir Relief & Development Foundation (KRDF)]
*[http://www.pbs.org/newshour/science/earthquake/ PBS NewsHour - Predicting Earthquakes]
*[http://neic.usgs.gov/neis/eqlists/10maps_world.html USGS – Largest earthquakes in the world since 1900]
*[http://www.armageddononline.org/earthquake.php The Destruction of Earthquakes] - a list of the worst earthquakes ever recorded
*[http://www.losangelesearthquakes.com Los Angeles Earthquakes plotted on a Google map]
*[http://www.em-dat.net the EM-DAT International Disaster Database]
*[http://www.earthquakearchive.com Earthquake Newspaper Articles Archive]
*[http://www.earth-quake.org Earth-quake.org]
*[http://www.petquake.org PetQuake.org]- official PETSAAF system which relies on strange or atypical animal behavior to predict earthquakes.(Link broken 03:33, 2 June 2008 (UTC))
*[http://carlogesualdo.altervista.org/pagine/terremoto_irpinia_1980.htm A series of earthquakes in southern Italy - November 23 1980, Gesualdo ]
*[http://earthquake.usgs.gov/eqcenter/recenteqsww/ Recent Quakes WorldWide]
*[http://www.aus-emaps.com/earthquakesRSS.php Real-time earthquakes on Google Map, Australia and rest of the world]
*[http://earthquakedb.com Earthquake Information] - detailed statistics and integrated with Google Maps and Google Earth
*[http://kharita.rm.ingv.it/Gmaps/rec/en/index.htm Kharita - INGV portal for Digital Cartography] - Last earthquakes recorded by INGV Italian Network (with Google Maps)
*[http://kharita.rm.ingv.it/Gmaps/reg/en/index.htm Kharita - INGV portal for Digital Cartography] - Italian Seismicity by region 1981-2006 (with Google Maps)
{{Geotechnical engineering|state=collapsed}}
[[Category:Earthquakes]]
[[Category:Seismology]]
[[Category:Geological hazards]]
{{Link FA|sk}}
[[af:Aardbewing]]
[[ar:زلزال]]
[[an:Tierratremo]]
[[az:Zəlzələ]]
[[bn:ভূমিকম্প]]
[[zh-min-nan:Tē-tāng]]
[[be:Землетрасенне]]
[[be-x-old:Землятрус]]
[[bs:Potres]]
[[br:Kren-douar]]
[[bg:Земетресение]]
[[ca:Terratrèmol]]
[[cv:Çĕр чĕтренĕвĕ]]
[[cs:Zemětřesení]]
[[cy:Daeargryn]]
[[da:Jordskælv]]
[[de:Erdbeben]]
[[et:Maavärin]]
[[el:Σεισμός]]
[[es:Terremoto]]
[[eo:Tertremo]]
[[eu:Lurrikara]]
[[fa:زمینلرزه]]
[[fr:Tremblement de terre]]
[[fy:Ierdskodding]]
[[gan:地震]]
[[gd:Crith-thalmhainn]]
[[gl:Terremoto]]
[[gu:ધરતીકંપ]]
[[ko:지진]]
[[hy:Երկրաշարժ]]
[[hi:भूकंप]]
[[hr:Potres]]
[[io:Ter-tremo]]
[[id:Gempa bumi]]
[[iu:ᓴᔪᑉᐱᓛᕗᖅ/sajuppilaavuq]]
[[is:Jarðskjálfti]]
[[it:Terremoto]]
[[he:רעידת אדמה]]
[[kn:ಭೂಕಂಪ]]
[[ka:მიწისძვრა]]
[[sw:Tetemeko la ardhi]]
[[la:Terrae motus]]
[[lv:Zemestrīce]]
[[lb:Äerdbiewen]]
[[lt:Žemės drebėjimas]]
[[hu:Földrengés]]
[[mk:Земјотрес]]
[[ml:ഭൂകമ്പം]]
[[ms:Gempa bumi]]
[[nah:Tlālollīn]]
[[nl:Aardbeving]]
[[ja:地震]]
[[no:Jordskjelv]]
[[nn:Jordskjelv]]
[[om:Chocho'a lafa]]
[[uz:Zilzila]]
[[nds:Eerdbeven]]
[[pl:Trzęsienie ziemi]]
[[pt:Sismo]]
[[ro:Cutremur]]
[[rm:Terratrembel]]
[[qu:Pacha kuyuy]]
[[ru:Землетрясение]]
[[sq:Tërmeti]]
[[scn:Tirrimotu]]
[[simple:Earthquake]]
[[sk:Zemetrasenie]]
[[sl:Potres]]
[[szl:Třyńśyńy źymje]]
[[sr:Земљотрес]]
[[sh:Potres]]
[[fi:Maanjäristys]]
[[sv:Jordbävning]]
[[tl:Lindol]]
[[ta:நிலநடுக்கம்]]
[[te:భూకంపం]]
[[th:แผ่นดินไหว]]
[[vi:Động đất]]
[[tg:Заминларза]]
[[tr:Deprem]]
[[uk:Землетрус]]
[[ur:زلزلہ کي تاريخ]]
[[vec:Teremoto]]
[[wa:Tronnmint d' tere]]
[[yi:ערדציטערניש]]
[[zh-yue:地震]]
[[zh:地震]]