Related topics: tsunami · japan · quake · tectonic plates · earth

Scientist gains fresh insight into the origins of earthquakes

Sometimes barely noticeable, and at other times devasting, earthquakes are a major geological phenomenon which provide a stark reminder that our planet is constantly evolving. Scientists have made significant progress in ...

Seismic data yields deeper quake knowledge

By examining data from large earthquakes, KAUST researchers have linked their magnitude, and the extent to which they cause aftershocks, to new depths in the Earth's crust: these are depths at which it was previously thought ...

Q&A: Behind the scenes with an earthquake scientist

Sylvain Barbot is trying to do what can't be done yet: reliably predict earthquakes. The assistant professor at the USC Dornsife College of Letters, Arts and Sciences knows that it's impossible—at least not yet. But he ...

The mysterious luminescence phenomena of earthquake lightning

Were you aware that earthquakes are sometimes associated with luminescence, called earthquake lightning? This phenomenon had been documented throughout history, such as between 1965 and 1967, the Matsushiro earthquake swarm ...

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Earthquake

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.

This text uses material from Wikipedia, licensed under CC BY-SA