Earthquake

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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

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Small faults in Southeast Spain reduce earthquake risk of larger ones

Small faults in Southeast Spain reduce earthquake risk of larger ones

Space & Earth / Earth Sciences

created Nov 25, 2009 | popularity not rated yet | comments 0

A team of Spanish scientists, studying recent, active deformations in the Baetic mountain range, have shown that the activity of smaller tectonic structures close to larger faults in the south east of the ...


Using new technique, scientists find 11 times more aftershocks for 2004 quake

Space & Earth / Earth Sciences

created Nov 23, 2009 | popularity 4.5 / 5 (2) | comments 0

(PhysOrg.com) -- Using a technique normally used for detecting weak tremor, scientists at the Georgia Institute of Technology discovered that the 2004 magnitude 6 earthquake along the Parkfield section of the San Andreas ...


Wu Chang Gong temple in Taiwan was partially levelled by a powerful earthquake ten years ago

Taiwan to boost quake warning system

Space & Earth / Earth Sciences

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

Taiwan plans to build its first undersea seismic station, designed to improve the island's early warning system and save valuable seconds when earthquakes strike, officials said.


Noise Evidence Could Expand Hurricane Record

Noise Evidence Could Expand Hurricane Record

Space & Earth / Earth Sciences

created Nov 10, 2009 | popularity 5 / 5 (3) | comments 0

As sea-surface temperatures rise across the globe, some scientists believe that hurricane frequency and intensity may increase. A fresh technique offers promise to generate new data from long-dead storms, ...


Excavation unravels mysteries of men's gymnasium's demise during 1906 earthquake

Excavation unravels mysteries of men's gymnasium's demise during 1906 earthquake

Other Sciences / Archaeology & Fossils

created Nov 10, 2009 | popularity 5 / 5 (1) | comments 0

More than a year into an excavation project of the men's gymnasium that was destroyed by the 1906 earthquake, Stanford university archaeologist Laura Jones' team has unearthed evidence suggesting why the newly ...


Deep creep means milder, more frequent earthquakes along Southern California's San Jacinto fault

Deep creep means milder, more frequent earthquakes along Southern California's San Jacinto fault

Space & Earth / Earth Sciences

created Nov 08, 2009 | popularity 3.8 / 5 (6) | comments 1

With an average of four mini-earthquakes per day, Southern California's San Jacinto fault constantly adjusts to make it a less likely candidate for a major earthquake than its quiet neighbor to the east, the ...


earthquake

Earthquakes actually aftershocks of 19th century quakes

Space & Earth / Earth Sciences

created Nov 04, 2009 | popularity 4.4 / 5 (19) | comments 13

(PhysOrg.com) -- When small earthquakes shake the central U.S., citizens often fear the rumbles are signs a big earthquake is coming. Fortunately, new research instead shows that most of these earthquakes ...


Earthquake early-warning system soon to enter testing

Space & Earth / Earth Sciences

created Oct 20, 2009 | popularity 5 / 5 (3) | comments 0

It is the Holy Grail of seismology, sought by earthquake scientists for more than a century: the ability to provide advance warning of the Big One, so the public can react before a massive quake unleashes its rolling thunder ...


Research gives glimpse of tectonic history on Puget Sound-region fault zones

Space & Earth / Earth Sciences

created Oct 19, 2009 | popularity 5 / 5 (2) | comments 0

(PhysOrg.com) -- New research on the Kitsap Peninsula, at the west edge of Washington state's Puget Sound, finds evidence that land was raised at least 6 feet by ancient earthquakes.


Satellite data look behind the scenes of deadly earthquake

Satellite data look behind the scenes of deadly earthquake

Space & Earth / Earth Sciences

created Oct 15, 2009 | popularity 4.6 / 5 (7) | comments 0

Using satellite radar data and GPS measurements, Chinese researchers have explained the exceptional geological events leading to the 2008 Wenchuan Earthquake that killed nearly 90 000 people in China's Sichuan ...


Indonesian residents clear debris after a 7.6-magnitude earthquake

Colossal quake may hit Sumatra in 30 years: geologist

Space & Earth / Earth Sciences

created Oct 15, 2009 | popularity 2.7 / 5 (3) | comments 1

A colossal earthquake may hit Indonesia's Sumatra island within 30 years, triggering a tsunami and making last month's deadly temblor look tiny by comparison, a geologist has warned.


Indonesian soldiers crawl under a collapsed building during a rescue attempt in the Sumatran city of Padang

Killer earthquakes shake scientific thought

Space & Earth / Earth Sciences

created Oct 11, 2009 | popularity 4.2 / 5 (16) | comments 14

A sudden cluster of massive earthquakes which has shaken Asia-Pacific communities and likely left thousands dead has also jolted some scientists, who are starting to question conventional thought.


Scientists obtain rocks moving into seismogenic zone

Scientists obtain rocks moving into seismogenic zone

Space & Earth / Earth Sciences

created Oct 09, 2009 | popularity 3 / 5 (1) | comments 0

An international group of scientists aboard the Deep-Sea Drilling Vessel CHIKYU, operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) for the Integrated Ocean Drilling Program (IODP), ...


Australian continent to blame for Samoa, Sumatra quakes

Australian continent to blame for Samoa, Sumatra quakes

Space & Earth / Earth Sciences

created Oct 08, 2009 | popularity 4 / 5 (5) | comments 0

(PhysOrg.com) -- The recent earthquakes in the Pacific and Indonesia have one University of Queensland researcher questioning whether the two are related.


Wi-Fi signals can see through walls

Wi-Fi signals can see through walls

Technology / Engineering

created Oct 05, 2009 | popularity 4.1 / 5 (7) | comments 2

(PhysOrg.com) -- Researchers at the University of Utah, USA, have discovered that variations in signal strengths in wireless networks can be used to "see" movements of people on the other side of walls or ...