What do P and S waves tell us about earthquakes?
What can seismic waves tell us? Studies of the different types of seismic waves can tell us much about the nature of the Earth’s structure. For example, seismologists can use the direction and the difference in the arrival times between P-waves and S-waves to determine the distance to the source of an earthquake.
Do earthquakes cause S waves?
Types of Seismic Waves Body waves can travel through the Earth’s inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes send out seismic energy as both body and surface waves. The body waves (P and S) and surface waves recorded by a seismometer.
How are S and P waves different?
P waves are recorded earlier than S waves, because they travel at a higher velocity. P waves can travel through liquid and solids and gases, while S waves only travel through solids. Scientists use this information to help them determine the structure of Earth.
What kind of movement is an S wave?
S waves produce vertical and horizontal motion in the ground surface. Particle motion consists of alternating transverse motion. Particle motion is perpendicular to the direction of propagation (transverse).
What are the 3 types of waves in an earthquake?
There are three major kinds of seismic waves: P, S, and surface waves. P and S waves together are sometimes called body waves because they can travel through the body of the earth, and are not trapped near the surface. A P wave is a sound wave traveling through rock.
What happens to S and P waves as they travel inside Earth?
S waves cannot pass through the liquid outer core, but P waves can. The waves are refracted as they travel through the Earth due to a change in density of the medium. When the waves cross the boundary between two different layers, there is a sudden change in direction due to refraction. …
Do P or S waves cause more damage?
An earthquake generates a series of seismic waves that travel through the interior or near the surface of the Earth. S waves are more dangerous than P waves because they have greater amplitude and produce vertical and horizontal motion of the ground surface. The slowest waves, surface waves, arrive last.
What is stronger P or S waves?
S waves are more dangerous than P waves because they have greater amplitude and produce vertical and horizontal motion of the ground surface. The slowest waves, surface waves, arrive last. They travel only along the surface of the Earth. There are two types of surface waves: Love and Rayleigh waves.
Where do P waves travel the fastest?
Because the earth’s mantle becomes more rigid and compressible as the depth below the asthenosphere increases, P-waves travel faster as they go deeper in the mantle. The density of the mantle also increases with depth below the asthenosphere. The higher density reduces the speed of seismic waves.
What does S in S wave stand for?
An S wave, or shear wave, is a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is moving.
Where do S waves move?
S waves shake the ground in a shearing, or crosswise, motion that is perpendicular to the direction of travel. These are the shake waves that move the ground up and down or from side to side. S waves are called secondary waves because they always arrive after P waves at seismic recording stations.
What is an S wave?
In seismology, S-waves, secondary waves, or shear waves (sometimes called an elastic S-wave) are a type of elastic wave, and are one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves. The S-wave is a transverse wave, meaning that, in the simplest situation,…
What are the causes of earthquake?
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 or hypocenter.
What is the speed of earthquake waves?
The speed of seismic wave, the P wave (or primary wave, which is the fastest kind of seismic wave) is about 8 km per second, or 30,000 km per hour.
How do seismic waves affect earthquakes?
During an earthquake, energy is released in seismic waves that travel from where the earthquake starts, a place called the focus. The seismic waves radiate from the focus. Seismic waves cause intense shaking at the Earth surface that can cause buildings and roads to collapse.