# How fast do seismic waves propagate?

## How fast do seismic waves propagate?

Seismic waves travel fast, on the order of kilometers per second (km/s). The precise speed that a seismic wave travels depends on several factors, most important is the composition of the rock.

### How do you calculate wave propagation velocity?

1. The relationship between the propagation speed, frequency, and wavelength is vw=fλ.
2. The relationship between the propagation speed, frequency, and wavelength is vw=fλ.
3. The relationship between the propagation speed, frequency, and wavelength is vw=λf.

What is the propagation of seismic waves?

Seismic wave propagation is a ground motion phenomenon that relates to the passage of body waves, including compression waves and shear waves, radially from the source of earthquake energy release (hypocenter) into the surrounding rock and soil medium.

What does the velocity of seismic wave propagation depend on?

Seismic wave fields are recorded by a seismometer, hydrophone (in water), or accelerometer. The propagation velocity of the waves depends on density and elasticity of the medium. Velocity tends to increase with depth and ranges from approximately 2 to 8 km/s in the Earth’s crust up to 13 km/s in the deep mantle.

## What is the velocity of a wave?

Wave velocity in common usage refers to speed, although, properly, velocity implies both speed and direction. The velocity of a wave is equal to the product of its wavelength and frequency (number of vibrations per second) and is independent of its intensity.

### What factors affect seismic wave velocity?

Composition, temperature, and pressure are all factors that can affect seismic velocity in the mantle. Laboratory elasticity data show that a decrease of 1% in the Mg/(Mg+Fe) ratio in olivine reduces the velocity by an amount equivalent to that caused by a temperature increase of 70 K.

What are the two major types of seismic waves?

The two main types of waves are body waves and surface 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.

What is the 2 main types of seismic waves?

## What causes seismic waves to increase in speed?

The overall increase in seismic wave speed with depth into Earth produces an upward curvature to rays that pass through the mantle. A notable exception is caused by the decrease in velocity from the mantle to the core.

### How are compressions and dilations related to seismic waves?

Alternating compressions (“pushes”) and dilations (“pulls”) which are directed in the same direction as the wave is propagating (along the ray path); and therefore, perpendicular to the wavefront. VP~ 5 – 7 km/s in typical Earth’s crust; >~ 8 km/s in Earth’s mantle and core; ~1.5 km/s in water; ~0.3 km/s in air.

What is the typical propagation speed of a S wave?

Typical S-wave propagation speeds are on the order of 1 to 8 km/sec. The lower value corresponds to the wave speed in loose, unconsolidated sediment, the higher value is near the base of Earth’s mantle.

How are seismic wave velocities related to elastic properties?

Seismic Wave Velocities¶. Rocks and other materials can be characterized by their elastic properties. However, seismic velocities represent a more practical set of physical properties for seismic methods. Seismic velocities define the speed at which various elastic deformations propagate through materials.