Earthquake

Definition

Sudden movement of a block of the Earth’s crust along a geological fault and associated ground shaking (IRDR Glossary).

Earthquake can be defined as the shaking of earth caused by waves moving on and below the earth's surface and causing: surface faulting, tremors vibration, liquefaction, landslides, aftershocks and/or tsunamis (WHO).

Facts and figures

The size or magnitude of earthquakes is determined by measuring the amplitude of the seismic waves recorded on a seismograph and the distance of the seismograph from the earthquake. These are put into a formula which converts them to a magnitude, which is a measure of the energy released by the earthquake. For every unit increase in magnitude, there is roughly a thirty-fold increase in the energy released. Earthquake magnitude was traditionally measured on the Richter scale. It is often now calculated from seismic moment, which is proportional to the fault area multiplied by the average displacement on the fault (Australian Government).

There are four different types of earthquakes: tectonic, volcanic, collapse and explosion.

A tectonic earthquake is one that occurs when the earth's crust breaks due to geological forces on rocks and adjoining plates that cause physical and chemical changes.
A volcanic earthquake is any earthquake that results from tectonic forces which occur in conjunction with volcanic activity.
A collapse earthquake are small earthquakes in underground caverns and mines that are caused by seismic waves produced from the explosion of rock on the surface.
An explosion earthquake is an earthquake that is the result of the detonation of a nuclear and/or chemical device.

Further information

USGS Earthquakes

PreventionWeb Earthquakes

UN-SPIDER Regional Support Offices with hazard-specific expertise

Title: Asian Disaster Reduction Center (ADRC)

Title: Germany Regional Support Office

Title: Greece Regional Support Office

Title: Indonesia Regional Support Office

Title: International Centre for Integrated Mountain Development (ICIMOD)

Title: Pakistan Regional Support Office

Title: United States of America Regional Support Office

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M=5.3 earthquake hit the northern province of Samangan, killing at least 11, injuring over 70, destroying over 2,000 houses.

Source: GlideNumber
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At least 300 people have died and others are trapped under rubble after a magnitude-6.9 earthquake struck China's Qinghai province, officials say.
The powerful tremor hit remote Yushu county, 500km (310 miles) south-west of provincial capital Xining, at 0749 (2349 GMT), at a shallow depth of 10km.
Source: GlideNumber, BBC

Available Space-based Information for: Earthquake in NW China (14/4/2010)
Status Update: 05/05/2010

UNOOSA/UN-SPIDER:
Focal Point: Peter Podprocky, Lorant Czaran
Email: un-spider [at] unoosa.org
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Earthquake in Mexico

A major 7.2 magnitude earthquake struck near the Mexico-California border on Sunday, killing at least one person and around 100 people injured as it rocked buildings, ruptured a highway.

Source: GlideNumber
Earthquake in Indonesia

On 4/6/2010 10:15:02 PM UTC (about 04:43h local time) an earthquake of magnitude 7.8 occurred in the moderately populated region of Aceh in Indonesia. It is likely that a tsunami, at maximum height of 0.7m, was generated. GDACS red alert was issued.

For more information please visit: http://www.gdacs.org/#EQ_84222

Source: GlideNumber, GDACS
Earthquake in Chile

On 3/11/2010 2:39:48 PM, an earthquake of magnitude 7.2 and depth 35km occurred in Chile. This earthquake potentially affected 771000 people. Tsunami waves are estimated to be lower than 10cm. More information www.gdacs.org.

Source GLIDEnumber
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M=6.0 earthquake, with its epicentre at Basyurt in Elazig province, killed 17 in eastern Turkey and many seem to be trapped under rubble.
Source: GLIDEnumber

Available Space-based Information for: Earthquake in Turkey (08/03/2010)
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UNOOSA/UN-SPIDER
Email: un-spider [at] unoosa.org
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A powerful earthquake and more than a dozen aftershocks jolted southern Taiwan on Thursday, injuring 96 people, toppling farm houses and derailing a carriage on a high-speed train. Panicked residents fled shaking buildings and children were rushed out of schools in the 6.4-magnitude quake, which also momentarily cut off electricity to more than half a million homes.

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GDACS red alert as 8.3-magnitude quake hits Chile.
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Source: www.glidenumber.net/glide/public/search/details.jsp

Available Space-based Information for: Earthquake and Tsunami in Chile (27/02/2010)

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On 1/12/2010 9:53:09 PM UTC an earthquake of magnitude 7 and depth 10km has struck an very highly populated area in the Ouest Province (population: 2.2 million) in Haiti. GDACS estimates the likelihood for need of international humanitarian intervention to be high (Red alert).
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500 houses have been damaged or destroyed. The National Disaster Management Office says hundreds of people could be homeless. Only a few minor injuries are reported.
Source: www.glidenumber.net

Available Space-based Information for: Solomon Islands – Earthquake – Date 4 January 2010

Status Update: 5 January 2010

UNOOSA/UN-SPIDER:
Contact email: un-spider [at] unoosa.org
Link: http://www.un-spider.org/
International Charter:
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