"or hypocenter. The epicenter is the point at ground level directly above the hypocenter. Tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the fault surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior. Once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored"
"Ground zero In terms of nuclear explosions and other large bombs, the term ""ground zero"" (also known as ""surface zero"") describes the point on the Earth's surface closest to a detonation. In the case of an explosion above the ground, ""ground zero"" refers to the point on the ground directly below the nuclear detonation and is sometimes called the hypocenter (from Greek ὑπο- ""under-"" and center). Generally, the term ""ground zero"" is also used in relation to earthquakes, epidemics, and other disasters to mark the point of the most severe damage or destruction. The term is distinguished from the term"
"Epicenter The epicenter, epicentre or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. In most earthquakes, the epicenter is the point where the greatest damage takes place, but the length of the subsurface fault rupture may indeed be a long one, and damage can be spread on the surface across the entire rupture zone. As an example, in the magnitude 7.9 2002 Denali earthquake in Alaska, the epicenter was at the western end of the rupture, but the greatest damage was about"
"Hypocenter A hypocenter (or hypocentre) (from [""hypόkentron""] for 'below the center') is the point of origin of an earthquake or a subsurface nuclear explosion. In seismology, it is a synonym of the focus. The term ""hypocenter"" is also used as a synonym for ""ground zero"", the surface point directly beneath a nuclear airburst. An earthquake's hypocenter is the position where the strain energy stored in the rock is first released, marking the point where the fault begins to rupture. This occurs directly beneath the epicenter, at a distance known as the focal or hypocentral depth. The focal depth can be"
"the Park51 project that was to be located two blocks away from the site labeled it the ""Ground Zero mosque."" In advance of the 10th anniversary of the attacks, New York City mayor Michael Bloomberg urged that the ""ground zero"" moniker be retired, saying, ""...the time has come to call those 16 acres what they are: The World Trade Center and the National September 11th Memorial and Museum."" Ground zero In terms of nuclear explosions and other large bombs, the term ""ground zero"" (also known as ""surface zero"") describes the point on the Earth's surface closest to a detonation. In"
"place on earth where rocks from the earth's mantle are being actively exposed above sea-level. On 23 December 2004, an earthquake measuring 8.1 on the moment magnitude scale rocked the island but caused no significant damage. Geoscience Australia issued a Tsunami Inundation Advice for Macquarie Island Station. The paper indicates that in certain scenario, a significant tsunami caused by a local earthquake could occur with no warning possible, and could inundate the isthmus where the existing station resides. Such a tsunami would likely affect other parts of the coastline and field huts located close to the shore. Such a significant"
"Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to toss people around and destroy whole cities. The seismicity, or seismic activity, of an area is the frequency, type and size of earthquakes experienced over a period of time. The word ""tremor"" is also used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes"
"seismic waves. At the Earth's surface, earthquakes manifest themselves by vibration, shaking, and sometimes displacement of the ground. Earthquakes are caused by slippage within geological faults. The underground point of origin of the earthquake is called the ""seismic focus"". The point directly above the focus on the surface is called the ""epicenter"". Earthquakes by themselves rarely kill people or wildlife. It is usually the secondary events that they trigger such as building collapse, fires, tsunamis (seismic sea waves) and volcanoes. Many of these could possibly be avoided by better construction, safety systems, early warning and planning. When natural erosion, human"
"the Earth's surface of the boundary between the downgoing and overriding plates. This trench is created by the gravitational pull of the relatively dense subducting plate pulling the leading edge of the plate downward. Multiple earthquakes occur along this subduction boundary with the seismic hypocenters located at increasing depth under the island arc: these quakes define the Wadati–Benioff zones. The volcanic arc forms when the subducting plate reaches a depth of about 100 km. Ocean basins that are being reduced by subduction are called 'remnant oceans' as they will slowly be shrunken out of existence and crushed in the subsequent"
"1975; September 22, 1976; September 27, 1979; September 21, 1990; and July 29, 1991. Earthquakes happen when two blocks of the Earth's crust move relative to one another. The place where the blocks meet is called a fault, and faults tend to show up as relatively straight lines on maps. Any structure built directly on top of the fault will be torn in two when the blocks move. Constructing a building to withstand this sort of movement (often several feet in a matter of seconds) is not practical, so it is best to avoid building directly on top of an"
"Deep-focus earthquake A deep-focus earthquake in seismology (also called a plutonic earthquake) is an earthquake with a hypocenter depth exceeding 300 km. They occur almost exclusively at convergent boundaries in association with subducted oceanic lithosphere. They occur along a dipping tabular zone beneath the subduction zone known as the Wadati–Benioff zone. Preliminary evidence for the existence of deep-focus earthquakes was first brought to the attention of the scientific community in 1922 by Herbert Hall Turner. In 1928, Kiyoo Wadati proved the existence of earthquakes occurring well beneath the lithosphere, dispelling the notion that earthquakes occur only with shallow focal depths."
"For example, ""Travel is restricted in the Chinese province thought to be the epicentre of the SARS outbreak."" ""Garner's Modern American Usage"" gives several examples of such use. Garner also refers to a William Safire article in which Safire quotes a geophysicist as attributing the use of the term to ""spurious erudition on the part of writers combined with scientific illiteracy on the part of copy editors"". Nevertheless, Garner has noted that these usages may describe ""focal points of unstable and potentially destructive environments."" Epicenter The epicenter, epicentre or epicentrum in seismology is the point on the Earth's surface directly"
"Asthenosphere The asthenosphere (from Greek ἀσθενής ""asthenḗs"" 'weak' + ""sphere"") is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth. It lies below the lithosphere, at depths between approximately below the surface. The Lithosphere-Asthenosphere boundary is usually referred to as LAB. The asthenosphere is almost solid, although some of its regions could be molten (e.g., below mid-ocean ridges). The lower boundary of the asthenosphere is not well defined. The thickness of the asthenosphere depends mainly on the temperature. However, the rheology of the asthenosphere also depends on the rate of deformation, which suggests"
"an instrument generally consisting of a constantly unwinding roll of paper, anchored to a fixed place, and a pendulum or magnet suspended with a marking device above the roll, to record actual earth motion during an earthquake. The scale takes into account the instrument's distance from the epicenter, or the point on the ground that is directly above the earthquake's origin. Richter chose to use the term ""magnitude"" to describe an earthquake's strength because of his early interest in astronomy; stargazers use the word to describe the brightness of stars. Gutenberg suggested that the scale be logarithmic so an earthquake"
"Submarine earthquake A submarine, undersea, or underwater earthquake is an earthquake that occurs underwater at the bottom of a body of water, especially an ocean. They are the leading cause of tsunamis. The magnitude can be measured scientifically by the use of the moment magnitude scale and the intensity can be assigned using the Mercalli intensity scale. Understanding plate tectonics helps to explain the cause of submarine earthquakes. The Earth's surface or lithosphere comprises tectonic plates which average approximately 50 miles in thickness, and are continuously moving very slowly upon a bed of magma in the asthenosphere and inner mantle."
"Subaerial In natural science, subaerial (literally ""under the air""), has been used since 1833, notably in geology and botany, to describe events or features that are formed, located, or taking place immediately on or near the Earth's land surface. They are thus exposed to Earth's atmosphere. This may be contrasted with ""subaqueous"" events or features located below a water surface, ""submarine"" events or features located below a sea surface, ""subterranean"" events or features located below ground, or ""subglacial"" events or features located below glacial ice such as ice sheets. For example, a subaerial eruption of a volcano is one that"
"Surface rupture Surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where there is no displacement at ground level. This is a major risk to any structure that is built across a fault zone that may be active, in addition to any risk from ground shaking. Surface rupture entails vertical or horizontal movement, on either side of a fault which has ruptured. Surface rupture can affect large areas of land. Not every earthquake results in"
"value of Earth's radius may be approximated by the average of these radii. As a result of Earth's equatorial bulge, the highest point on Earth, measured from the center and outwards, is the peak of Mount Chimborazo in Ecuador rather than Mount Everest. But since the ocean also bulges, like Earth and its atmosphere, Chimborazo is not as high above sea level as Everest is. The standard formula for this force is the relationship formula_1. However, velocity at the surface is equal to the product of radius and rotational velocity, and therefore the force is directly proportional to radius. Viewing"
"Some of the largest, most devastating earthquakes that have occurred in the last century have been identified as interplate events. Some areas of the world that are particularly prone to interplate earthquakes due to the presence of prominent plate boundaries include the west coast of North America (especially California and Alaska), the northeastern Mediterranean region (Greece, Italy, and Turkey in particular), Iran, New Zealand, Indonesia, India, Japan, and parts of China.Major Earthquakes (Magnitude >= 9.0) Since 1900<mapframe latitude=""36"" longitude=""1"" zoom=""1"" width=""500"" height=""300"" align=""center""> </mapframe> Interplate earthquake An interplate earthquake is an earthquake that occurs at the boundary between two tectonic"
"different types of material fall or slide rapidly under the force of gravity. Avalanches are often classified by the size or severity of consequences resulting from the event. An earthquake is the sudden release of energy stored as lithospheric stress that radiates seismic waves. At the Earth's surface, earthquakes may manifest with a shaking or displacement of the ground; when the earthquake occurs on the seafloor, the resulting displacement of water can sometimes result in a tsunami. Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-km-long, horseshoe-shaped zone called the circum-Pacific seismic belt,"
"Earthquake rupture An earthquake rupture is the extent of slip that occurs during an earthquake in the Earth's crust. Earthquakes occur for many reasons that include: landslides, movement of magma in a volcano, the formation of a new fault, or, most commonly of all, a slip on an existing fault. A tectonic earthquake begins by an initial rupture at a point on the fault surface, a process known as nucleation. The scale of the nucleation zone is uncertain, with some evidence, such as the rupture dimensions of the smallest earthquakes, suggesting that it is smaller than 100 m while other"
"manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity. In its most general sense, the word ""earthquake"" is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus"
"of a surface). The name comes from seeing the ideal triangles or the pants as tectonic plates and the shear as plate motion. More generally one can do earthquakes along geodesic laminations. A theorem of Thurston then states that two points in Teichmüller space are joined by a unique earthquake path. A quasiconformal mapping between two Riemann surfaces is a homeomorphism which deforms the conformal structure in a bounded manner over the surface. More precisely it is differentiable almost everywhere and there is a constant formula_138, called the ""dilation"", such that where formula_140 are the derivatives in a conformal coordinate"
"curves for intermediate and deep earthquakes. Depth of focus (tectonics) In seismology, the depth of focus or focal depth refers to the depth at which an earthquake occurs. Earthquakes occurring at a depth of less than are classified as shallow-focus earthquakes, while those with a focal depth between and are commonly termed mid-focus or intermediate-depth earthquakes. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, deep-focus earthquakes may occur at much greater depths in the mantle, ranging from up to . The cause of deep-focus earthquakes is still not entirely understood since subducted lithosphere at"
"Spacequake In astrophysics, a spacequake is a temblor in the Earth's magnetic field. Though occurring in space, the effects of a spacequake can reach the surface of the Earth in the form of electromagnetic reverberations. The total energy in a spacequake can rival that of a magnitude 5 or 6 earthquake. Spacequakes are measured using a magnetometer and displayed with a magnetogram. The precursors for a spacequake were discovered by THEMIS in 2007, and were first reported in April 2010 in a publication in the ""Geophysical Research Letters"". Spacequakes are caused when jets of plasma come into contact with the"
"magnitude, destructive earthquakes, surface breaks are common. Fault ruptures in large earthquakes can extend for more than 100 km. When a fault ruptures unilaterally (with the epicenter at or near the end of the fault break) the waves are stronger in one direction along the fault. The word is derived from the New Latin noun ""epicentrum"", the latinisation of the ancient Greek adjective ἐπίκεντρος (""epikentros""), ""occupying a cardinal point, situated on a centre"", from ἐπί (""epi"") ""on, upon, at"" and κέντρον (""kentron"") ""centre"". The term was coined by the Irish seismologist Robert Mallet. It is also used to mean ""center""."
"Shadow zone A seismic shadow zone is an area of the Earth's surface where seismographs can only barely detect an earthquake after its seismic waves have passed through the Earth. When an earthquake occurs, seismic waves radiate out spherically from the earthquake's focus. The primary seismic waves are refracted by the liquid outer core of the Earth and are not detected between 104° and 140° (between approximately ) from the epicenter. The secondary seismic waves cannot pass through the liquid outer core and are not detected more than 104° (approximately ) from the epicenter. P waves that have been converted"
"Depth of focus (tectonics) In seismology, the depth of focus or focal depth refers to the depth at which an earthquake occurs. Earthquakes occurring at a depth of less than are classified as shallow-focus earthquakes, while those with a focal depth between and are commonly termed mid-focus or intermediate-depth earthquakes. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, deep-focus earthquakes may occur at much greater depths in the mantle, ranging from up to . The cause of deep-focus earthquakes is still not entirely understood since subducted lithosphere at that pressure and temperature regime should"
"earthquakes therefore lies in mathematical models which use simplified material properties and rheologies to simulate natural conditions. The strongest deep-focus earthquake in seismic record was the magnitude 8.3 Okhotsk Sea earthquake that occurred at a depth of 609 km in 2013. The deepest earthquake ever recorded was a small 4.2 earthquake in Vanuatu at a depth of 735.8 km in 2004. Deep-focus earthquake A deep-focus earthquake in seismology (also called a plutonic earthquake) is an earthquake with a hypocenter depth exceeding 300 km. They occur almost exclusively at convergent boundaries in association with subducted oceanic lithosphere. They occur along a"
"the point on the surface farthest from Earth's center of mass is the summit of the equatorial Chimborazo volcano in Ecuador. The average diameter of the reference spheroid is . Local topography deviates from this idealized spheroid, although on a global scale these deviations are small compared to Earth's radius: The maximum deviation of only 0.17% is at the Mariana Trench ( below local sea level), whereas Mount Everest ( above local sea level) represents a deviation of 0.14%. In geodesy, the exact shape that Earth's oceans would adopt in the absence of land and perturbations such as tides and"
"also important not to pathologize the reactions to loss and displacement or disruption of governmental administration and services, but rather to validate these reactions, to support constructive problem-solving and reflection as to how one might improve the conditions of those affected. Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to toss people around"
"Interplate earthquake An interplate earthquake is an earthquake that occurs at the boundary between two tectonic plates. Earthquakes of this type account for more than 90 percent of the total seismic energy released around the world. If one plate is trying to move past the other, they will be locked until sufficient stress builds up to cause the plates to slip relative to each other. The slipping process creates an earthquake with relative displacement on either side of the fault, resulting in seismic waves which travel through the Earth and along the Earth's surface. Relative plate motion can be lateral"
"covering point of three tectonic plates. The Indian plate, Eurasia plate, and the Arabian plate meet and converge in this area. There is no method to accurately predict an earthquake, however, there are systems which attempt to give early warnings when earthquakes occur. Currently the most all-inclusive system is Japan's Earthquake Early Warning system. This system is monitored by the Japanese Meteorological Agency The JMA sends out the warnings through the television, mobile devices, the internet, and the radio as soon as an earthquake is detected. Other countries have similar systems that are mostly limited to a particular region, for"