Earthquakes and seismic waves

At any one point this movement may take place not at once but rather in irregular steps; these sudden slowings and restartings give rise to the vibrations that propagate as seismic waves.

Surface waves are created when P and S waves reach the surface of the earth and produce the most destruction. Body waves travel within the earth. How does a seismograph record seismic waves?

P primaryS secondaryLove, and Rayleigh. The basic seismic waves are S-waves, P-waves, and L-waves, and they are discussed in related questions.

There are two basic families of seismic waves. This sudden brittle failure causes all of the elastic potential energy to be released at one time in the form of seismic waves, just as if a spring or elastic band that was being stretched suddenly snapped.

Such series of earthquakes are called earthquake swarms. Such irregular properties of fault rupture are now included in the modeling of earthquake sources, both physically and mathematically.

The Earthquakes and seismic waves propagate rapidly through the rock, usually tending in the same direction and sometimes extending many kilometres along a local zone of weakness. There also are striking connected belts of seismic activity, mainly along oceanic ridges —including those in the Arctic Oceanthe Atlantic Oceanand the western Indian Ocean —and along the rift valleys of East Africa.

Surface waves are created when P and S waves reach the surface of the earth and produce the most destruction. Deeper earthquakes, having less interaction with the surface, produce weaker surface waves.

The deeper-focus earthquakes commonly occur in patterns called Benioff zones that dip into the Earth, indicating the presence of a subducting slab.

Brittle failures are failures where fractures form through the material. In most Benioff zones, intermediate- and deep-earthquake foci lie in a narrow layer, although recent precise hypocentral locations in Japan and elsewhere show two distinct parallel bands of foci 20 km apart.

Because of the differences in types of rock the wave travels as well as variations in temperature and pressure. The frequency of occurrence falls off rapidly with increasing focal depth in the intermediate range.

These factors can be estimated for an existing fault to determine the magnitude of past earthquakes, or what might be anticipated for the future. S or secondary waves also move through the body of the earth but are slightly slower than P waves and produce perpendicular wave motion.

The type of seismic wave depends on what? We can pinpoint the location of the epicenter by triangulation using the distances determined from three or more seismographs.


In most instances, however, the first principal earthquake of a series is much more severe than the aftershocks. Seismic Waves - are mechanical vibrations that occur inside theEarth caused by the breaking of rocks.

What are seismic waves?

Seismic waves are used indirectly I have a question for you is this from a chapter 9 science packet section one because I have the same. Infor instance, the San Andreas Fault slipped along a plane km miles long. The difference in the arrival time of P and S waves at different seismic sensors allow seismologists to use triangulation to locate the epicenter of an earthquake.

Primary Earthquakes and seismic waves or P waves are the first waves to arrive and move in an accordion-like motion. Whether it is moving or at rest, every object resists any change to its motion. Seismic waves occur when earthquakes happen.

There are 3 broad types of seismic waves, Surface waves, S-waves and P-waves. In some cases an earthquake may be followed by 1, or more aftershocks a day.

Earthquakes associated with volcanic activity often occur in swarms, though swarms also have been observed in many nonvolcanic regions. The type of seismic wave depends on what? The first P-wave onset starts from the spot where an earthquake originates. There are two major categories of seismic waves - body waves, of which there are two different types P and S wavesand surface waves, which also consist of two different types Love and Rayleigh waves.

Notably, it measured the amplitude of surface waves which generally produce the largest amplitudes for a period of "about 20 seconds".

In strike-slip faulting, the rocks slip past each other horizontally. Body waves happen inside the earth and are called P longitudinal and S transverse waves. Primary waves or P waves are the first waves to arrive and move in an accordion-like motion.

Fault rupture starts at the earthquake focus, a spot that in many cases is close to 5—15 km under the surface.Earthquake magnitude and ground-shaking intensity. The Earth's crust is stressed by tectonic forces. When this stress becomes great enough to rupture the crust, or to overcome the friction that prevents one block of crust from slipping past another, energy is released, some of it in the form of various kinds of seismic waves that cause ground.

earthquakes create seismic waves. Seismic waves have helped scientists learn the various densities of the Earth's many layers because the speed of primary shock waves moving through the earth generally increas es with depth. This is because as density increases, seismic wave velocity increases.

earthquakes: types of seismic waves Seismic waves travel in different patterns and at different speeds through the Earth. The most damaging are the surface types—the Love waves and the Rayleigh waves.

Aug 23,  · Earthquake: Earthquake, any sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks. Earthquakes occur most often along geologic faults, narrow zones where rock masses move in relation to one another. Learn more about the causes and effects of earthquakes in this article.

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Earthquakes and seismic waves
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