what causes an earthquake?

Question

simple enogh

Answer 1

An earthquake is a phenomenon that results from and is powered by the sudden release of stored energy in the crust that propagates seismic waves. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes tsunamis, which may lead to loss of life and destruction of property.

Earthquakes may occur naturally or as a result of human activities. 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.

Most naturally occurring earthquakes are related to the tectonic nature of the Earth. Such earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patchwork of plates in slow but constant motion caused by the heat in the Earth's mantle and core. Plate boundaries grind past each other, creating frictional stress. When the frictional stress exceeds a critical value, called local strength, a sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the fault plane. When the failure at the fault plane results in a violent displacement of the Earth's crust, the elastic strain energy is released and seismic waves are radiated, thus causing an earthquake. This processes of strain, stress, and failure is referred to as the Elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth and is converted into heat. Therefore, earthquakes lower the Earth's available potential energy, though these losses are negligible.

Induced earthquakes

Some earthquakes have anthropogenic sources, such as extraction of minerals and fossil fuel from the Earth's crust, the removal or injection of fluids into the crust, reservoir-induced seismicity, massive explosions, and collapse of large buildings. Seismic events caused by human activity are referred to by the term induced seismicity. They however are not strictly earthquakes and usually show a different seismogram than earthquakes that occur naturally.

Answer 2

The earth's crust consists of many plates which get pushed around by movements in the flowing plastic mantle below. Sometimes, these plates run head on itno each other, and one then slides underneath the other. Where this sliding is happening, sometimes the plates get mechanically locked together at some small area, while the plates further from this area continue to slide. This builds up pressure on the sticking point until the locked up area can no longer resist the pressure. Then the locked up region breaks loose and the plates catch up quickly with the parts of the plates which had continued to move. This is the quake. There may also be a type of quake caused when the leading edge of the plate which has been driven under, subject to very high temperature and pressure, suddenly changes from one crystaline form to another. The crystaline form caused by the high temperature and pressure is a more dense form, taking up less space, so this phase change is also a sudden reduction in volume. That sudden reduction in volume allows things to move very quickly in filling the emptied volume, so, again, you get a quake.
. Another way plate movements cause quakes is when plates move in opposite directions along a line where they touch. As these jagged edges slide along, a couple of jagged points on the two plates might get locked against each other, causing a build up fo stress the same as with one plate sliding beneath another, and again, when this locked up area snaps, you gat an earthquake.

Answer 3

An earthquake is the consequence of a unexpected launch of potential interior the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, additionally huge-unfold as a seismograph. the 2d value of an earthquake is conventionally pronounced, or the proper and extra often than not out of date Richter value, with value 3 or decrease earthquakes being extra often than not imperceptible and value 7 inflicting severe injury over super factors. intensity of shaking is measured on the changed Mercalli scale. on the Earth's floor, earthquakes take place themselves via a shaking and in some situations displacement of the floor. while a huge earthquake epicenter is placed offshore, the seabed in some situations suffers adequate displacement to reason a tsunami. The shaking in earthquakes could additionally set off landslides and in some situations volcanic activity. In its maximum well-known sense, the be conscious earthquake is used to describe any seismic journey—whether a organic phenomenon or an journey led to via people—that generates seismic waves. Earthquakes are led to extra often than not via rupture of geological faults, extensive quantities of gas migration, particularly methane deep interior the earth, yet in addition via volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's factor of preliminary rupture is named its concentration or hypocenter. The term epicenter means the factor at floor point right now above this .

Answer 4

Learn to spell enough kid.
The earth has a molten center, heat and steam are always pushing outward.
Plates of rock are on top, always pushing against each other,
every so often the plates are pushed up and then they slide and this causes and earthquake.

Answer 5

when two plates on the earths crust collide together and create an earthquake.

Answer 6

Shifts in the tectonic plates.

Answer 7

the release of the constant pressure of the tectonic plates colliding

Answer 8

the Earth