Related topics: tectonic plates , tsunami , quake , san andreas fault , seismic activity



Earthquake

hide

An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. The moment magnitude of an earthquake is conventionally reported, or the related and mostly obsolete 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 scale.

At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing 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 waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter refers to the point at ground level directly above the hypocenter.

For more information about Earthquake, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with earthquake

results timeline


South China Sea Bridge

China Building 30-Mile Bridge Connecting Hong Kong to Guangdong Province

Technology / Engineering

created Dec 18, 2009 | popularity 4.8 / 5 (11) | comments 3

China Daily reports the commencement of the 30-mile Hong Kong-Zhuhai-Macao Bridge, the longest sea bridge under construction world-wide. The six-lane expressway will cut travel time from three-hours to around ...


Merapi volcano

Pre-eruption earthquakes offer clues to volcano forecasters

Space & Earth / Earth Sciences

created Dec 16, 2009 | popularity 4.7 / 5 (3) | comments 1

Like an angry dog, a volcano growls before it bites, shaking the ground and getting "noisy" before erupting. This activity gives scientists an opportunity to study the tumult beneath a volcano and may help ...


Tremors between slip events: More evidence of great quake danger to Seattle

Space & Earth / Earth Sciences

created Dec 15, 2009 | popularity 4.4 / 5 (8) | comments 0

(PhysOrg.com) -- For most of a decade, scientists have documented unfelt and slow-moving seismic events, called episodic tremor and slip, showing up in regular cycles under the Olympic Peninsula of Washington state and Vancouver ...


The quake was at a depth of 44.6 kilometres (27.7 miles)

Taiwan hit by 6.4-magnitude quake: USGS

Space & Earth / Earth Sciences

created Dec 20, 2009 | popularity not rated yet | comments 1

A strong 6.4-magnitude earthquake hit off eastern Taiwan on Saturday evening, the US Geological Survey said, the biggest tremor to rock the island this year.


Engineers help secure California highways and roads

Engineers help secure California highways and roads

Technology / Engineering

created Dec 15, 2009 | popularity not rated yet | comments 0

Sprays of dirt flew out of a soil box that held a retaining wall as it violently shook from a simulated 7.4 magnitude earthquake. The wall was put to test recently by engineers at the UC San Diego Englekirk ...


Researchers from France and Turkey scanned the Marmara's seabed over six weeks

Underwater gas may hold clues on Turkey quake risk

Space & Earth / Earth Sciences

created Dec 15, 2009 | popularity 5 / 5 (2) | comments 0

Natural gas that lies under Turkey's Marmara Sea close to Istanbul could provide advance warning of an earthquake experts believe will hit the country's largest city, scientists said on Tuesday.


USGS monitoring Twitter for earthquake details

Technology / Internet

created Dec 15, 2009 | popularity 3 / 5 (1) | comments 0

(AP) -- OMG! Earthquake!


Major volcanic eruption feared in Philippines (AP)

Major volcanic eruption feared in Philippines

Space & Earth / Earth Sciences

created Dec 20, 2009 | popularity 4.7 / 5 (6) | comments 0

(AP) -- The Philippines' most active volcano could have a huge eruption within days, officials warned Sunday after detecting a drastic surge in earthquakes and eerie rumbling sounds in surrounding foothills. ...