answersLogoWhite

0

Types of Seismic Waves

Earthquake shaking and damage is the result of three basic types of elastic waves. Two of the three propagate within a body of rock. The faster of these body waves is called the primary or P wave. Its motion is the same as that of a sound wave in that as it spreads out; it alternately pushes (compresses) and pulls (dilates) the rock. These P waves are able to travel through both solid rock, such as granite mountains, and liquid material, such as volcanic magma or the water of the oceans.

The slower wave through the body of rock is called the secondary or S wave. As an S wave propagates, it shears the rock sideways at right angles to the direction of travel. If a liquid is sheared sideways or twisted, it will not spring back, hence S waves cannot propagate in the liquid parts of the earth, such as oceans and lakes.

The actual speed of P and S seismic waves depends on the density and elastic properties of the rocks and soil through which they pass. In most earthquakes, the P waves are felt first. The effect is similar to a sonic boom that bumps and rattles windows. Some seconds later, the S waves arrive with their up-and-down and side-to-side motion, shaking the ground surface vertically and horizontally. This is the wave motion that is so damaging to structures.

The third general type of earthquake wave is called a surface wave, reason being is that its motion is restricted to near the ground surface. Such waves correspond to ripples of water that travel across a lake.

Surface waves in earthquakes can be divided into two types. The first is called a Love wave. Its motion is essentially that of S waves that have no vertical displacement; it moves the ground from side to side in a horizontal plane but at right angles to the direction of propagation. The horizontal shaking of Love waves is particularly damaging to the foundations of structures.

The second type of surface wave is known as a Rayleigh wave. Like rolling ocean waves, Rayleigh waves wave move both vertically and horizontally in a vertical plane pointed in the direction in which the waves are traveling.

Surface waves travel more slowly than body waves (P and S); and of the two surface waves, Love waves generally travel faster than Rayleigh waves. Love waves (do not propagate through water) can effect surface water only insofar as the sides of lakes and ocean bays pushing water sideways like the sides of a vibrating tank, whereas Rayleigh waves, because of their vertical component of their motion can affect the bodies of water such as lakes.

P and S waves have a characteristic which effects shaking: when they move through layers of rock in the crust, they are reflected or refracted at the interfaces between rock types. Whenever either wave is refracted or reflected, some of the energy of one type is converted to waves of the other type. A common example; a P wave travels upwards and strikes the bottom of a layer of alluvium, part of its energy will pass upward through the alluvium as a P wave and part will pass upward as the converted S-wave motion. Noting also that part of the energy will also be reflected back downward as P and S waves.

See the related Wikipedia link listed below for more information:

User Avatar

Wiki User

12y ago

What else can I help you with?

Related Questions

What are the different types of earthquakes waves?

The three types of earthquake waves are primary waves, surface waves, and secondary waves.


What are the 3 types of earthquakes wave?

The three types of earthquake waves are primary waves, surface waves, and secondary waves.


What types of waves are in an earthquake?

P waves (primary waves) and S waves (secondary waves).


What do earthquake waves have in common with other waves?

Earthquake waves, like other waves, transfer energy through a medium. They travel in a wave-like pattern, with characteristics such as amplitude, frequency, and wavelength. Additionally, earthquake waves can be reflected, refracted, and diffracted similar to other types of waves.


What types of waves are created in an earthquake?

seismic


What are earthquake waves?

Earthquake waves are vibrations that travel through the Earth's crust when an earthquake occurs. There are three main types of earthquake waves: primary (P) waves, secondary (S) waves, and surface waves. These waves can cause the ground to shake and can be detected by seismographs.


How do waves travel in an earthquake?

different forms of waves


What are three types of earthquake waves?

P-waves, S-waves and surface waves (Love and Rayleigh waves).


What tool is used to detect earthquake wave?

Seismographs are the primary tools used to detect earthquake waves. These instruments measure the motion of the ground caused by seismic waves generated during an earthquake. Seismographs can record different types of waves, including P-waves (primary waves) and S-waves (secondary waves), allowing scientists to analyze the earthquake's magnitude and location. The data collected is crucial for understanding seismic activity and assessing potential risks.


Are earthquake waves different from the concentric rings of waves when you throw a stone in the water?

Yes, earthquake waves are the result of the sudden release of energy in the Earth's crust during an earthquake, and they travel through the Earth in various forms such as P-waves, S-waves, and surface waves. When you throw a stone in the water, the concentric rings of waves are known as water surface waves, which propagate along the water's surface and are caused by the displacement of water molecules. Both types of waves involve the transfer of energy through a medium, but they occur in different contexts and mediums.


What are the three different types of waves?

The three different types of waves are mechanical waves, electromagnetic waves, and matter waves.


What are the three different wave types?

The three different wave types are transverse waves, longitudinal waves, and surface waves. Transverse waves oscillate perpendicular to the direction of wave propagation, longitudinal waves oscillate parallel to the direction of wave propagation, and surface waves travel along the boundary between two different mediums.