Difference between revisions of "Earthquake"
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==Definitions== | ==Definitions== | ||
*1: a shaking or trembling of the [[earth]] that is volcanic or [[tectonic]] in [[origin]] | *1: a shaking or trembling of the [[earth]] that is volcanic or [[tectonic]] in [[origin]] | ||
*2: upheaval | *2: upheaval | ||
==Description== | ==Description== | ||
| − | An '''earthquake''' (also known as a quake, tremor or temblor) is the result of a sudden release of [[energy]] in the [[Earth]]'s [ | + | An '''earthquake''' (also known as a quake, tremor or temblor) is the result of a sudden release of [[energy]] in the [[Earth]]'s [https://en.wikipedia.org/wiki/Crust_(geology) crust] that creates [https://en.wikipedia.org/wiki/Seismic_wave seismic waves]. The seismicity or seismic activity of an area refers to the [[frequency]], [[type]] and size of earthquakes experienced over a period of [[time]]. Earthquakes are [[measured]] with a [https://en.wikipedia.org/wiki/Seismometer seismometer]; a device which also records is known as a seismograph. The [https://en.wikipedia.org/wiki/Moment_magnitude_scale moment magnitude] (or the related and mostly obsolete [https://en.wikipedia.org/wiki/Richter_magnitude_scale Richter] magnitude) of an earthquake is conventionally reported, 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 [https://en.wikipedia.org/wiki/Mercalli_intensity_scale Mercalli scale]. The depth of the earthquake also matters: the more shallow the earthquake, the more damage to [[structures]] (all else being [[equal]]). |
| − | At the [[Earth]]'s surface, earthquakes [[manifest]] themselves by shaking and sometimes displacing the ground. When a large earthquake [ | + | At the [[Earth]]'s surface, earthquakes [[manifest]] themselves by shaking and sometimes displacing the ground. When a large earthquake [https://en.wikipedia.org/wiki/Epicenter epicenter] is located offshore, the seabed sometimes suffers sufficient displacement to cause a [https://en.wikipedia.org/wiki/Tsunami 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 [ | + | 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 [https://en.wikipedia.org/wiki/Underground_nuclear_testing nuclear tests]. An earthquake's point of initial rupture is called its [[focus]] or [https://en.wikipedia.org/wiki/Hypocenter hypocenter]. The term [https://en.wikipedia.org/wiki/Epicenter epicenter] refers to the point at ground level directly above the hypocenter.[https://en.wikipedia.org/wiki/Earthquake] |
[[Category: Earth Science]] | [[Category: Earth Science]] | ||
Latest revision as of 00:16, 13 December 2020
Definitions
Description
An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, 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. The depth of the earthquake also matters: the more shallow the earthquake, the more damage to structures (all else being equal).
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 tests. 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.[1]
