An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's Earth is the third planet from the Sun, and the fifth-largest of the eight planets in the Solar System. It is also the largest, most massive, and densest of the Solar System's four terrestrial (or rocky) planets. It is sometimes referred to as the World, the Blue Planet,[note 3] or Terra.[note 4] crust In geology, a crust is the outermost solid shell of a rocky planet or moon, which is chemically distinct from the underlying mantle. The crusts of Earth, our Moon, Mercury, Venus, Mars, Io, and other planetary bodies have been generated largely by igneous processes, and these crusts are richer in incompatible elements than their respective mantles that creates seismic waves Seismic waves are waves of force that travel through the Earth or other elastic body, for example as the result of an earthquake, explosion, or some other process that imparts forces to the body. Seismic waves are also continually excited on Earth by the incessant pounding of ocean waves and the wind. Seismic waves are studied by seismologists,. Earthquakes are recorded with a seismometer Seismometers are instruments that measure and record motions of the ground, including those of seismic waves generated by earthquakes, nuclear explosions, and other seismic sources. Records of seismic waves allow seismologists to map the interior of the Earth, and locate and measure the size of these different sources, also known as a seismograph. The moment magnitude The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of the area that slipped. The scale was developed in the 1970s (or the related and mostly obsolete Richter The Richter magnitude scale, also known as the local magnitude scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. It is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude of the largest displacement from zero on a Wood–Anderson torsion seismometer 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 Mercalli intensity scale is a scale used for measuring the intensity of an earthquake. The scale quantifies the effects of an earthquake on the Earth's surface, humans, objects of nature, and man-made structures on a scale of I through XII, with I denoting not felt, and XII one that causes almost complete destruction. The values will differ.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates. The word derives from the Neolatin noun epicentrum from the Greek adjective ἐπίκεντρος "central", from ἐπί (epi) "on, upon, at" and κέ is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami Earthquakes, volcanic eruptions and other underwater explosions , landslides and other mass movements, bolide impacts, and other disturbances above or below water all have the potential to generate 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 A phenomenon is any observable occurrence. In popular usage, a phenomenon often refers to an extraordinary event. In scientific usage, a phenomenon is any event that is observable, however commonplace it might be, even if it requires the use of instrumentation to observe it. For example, In physics, a phenomenon may be a feature of matter, energy, or an event caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults In geology, a fault or fault line is a planar fracture in rock in which the rock on one side of the fracture has moved with respect to the rock on the other side. Large faults within the Earth's crust are the result of differential or shear motion and active fault zones are the causal locations of most earthquakes. Earthquakes are caused by energy, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus The hypocenter or hypocentre , refers to the site of an earthquake or to that of a nuclear explosion. In the former, it is a synonym of the focus; in the latter, of ground zero or hypocenter The hypocenter or hypocentre , refers to the site of an earthquake or to that of a nuclear explosion. In the former, it is a synonym of the focus; in the latter, of ground zero. The term epicenter The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates. The word derives from the Neolatin noun epicentrum from the Greek adjective ἐπίκεντρος "central", from ἐπί (epi) "on, upon, at" and κέ refers to the point at ground level directly above the hypocenter.
Global earthquake epicenters The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates. The word derives from the Neolatin noun epicentrum from the Greek adjective ἐπίκεντρος "central", from ἐπί (epi) "on, upon, at" and κέ, 1963–1998 Global plate tectonic movement
Contents |
Science Daily (press release)
"There are large faults in the eastern part of the Baetic mountain range, which are active and occasionally cause moderate, low magnitude earthquakes ...
and more »
admin
Mon, 21 Dec 2009 18:32:30 GM
i need to know how knowing the intensity of an . earthquake. could be more useful than knowing the magnitude for rescuers in a particular area. please help as it is for my project due in 2 days!!! :( ...
