## What is P wave velocity?

Compressional or P-wave velocity (primary wave) measurements are a measure of the velocity of sound waves through Earth materials with distance vs. time. P-wave velocity data were collected on marine cores during DSDP; however, these measurements were taken at discrete locations.

### What is velocity of seismic wave?

seismic velocity: The speed with which an elastic wave propagates through a medium. For non-dispersive body waves, the seismic velocity is equal to both the phase and group velocities; for dispersive surface waves, the seismic velocity is usually taken to be the phase velocity.

#### How do you find the velocity of a P wave?

The velocity of a P wave can be expressed as:

- Velocity P wave = ((B + 1.3G)/Density)1/2, where: B = the bulk modulus – the resistance to change in volume. G = the Shear modulus – the resistance to change in shape. Density = mass/volume.
- Velocity S wave = (G/Density)1/2

**What is the initial velocity of P waves and S waves?**

When an earthquake occurs, seismic waves, including P and S waves carry energy away from the hypocenter in all directions. The P wave propagates with a velocity of about six kilometers per second in rock, while the S wave is slower at four kilometers per second.

**What affects P wave velocity?**

Pore fluid determines the elastic properties of the pore space. Since P-wave velocity is larger in water and oil than it is in air, the P-wave velocity of a rock is less impacted by porosity if the pore-space is saturated. Additionally, the S-wave velocity has been shown to depend on the density of the pore fluid.

## How does the P wave seismic velocity of the lower mantle compare to the P wave seismic velocity of the outer core?

Why do P waves have a higher velocity in the lower mantle than in the core even though the core has a much higher density? With the p wave’s velocity plotted from a depth of 0 km to a depth of 6371 km it shows the p wave velocity reaching about 14 km/sec by the time it reaches the bottom of the mantle.

### What does P in a P wave stand for?

Compressional waves are also called P-Waves, (P stands for “primary”) because they are always the first to arrive. Shear waves propagate more slowly through the Earth than compressional waves and arrive second, hence their name S- or secondary waves.

#### In what way is the P wave velocity plot different from the S wave velocity plot between the Earth’s surface and 2900 km depth?

(a) P-wave velocity has a higher value and a greater gradient than the S- wave velocity plot. P-wave velocity reduces sharply at 2900 km depth but not to zero as S-wave velocity does.

**What factors affect the velocity of P and S waves?**

Composition, temperature, and pressure are all factors that can affect seismic velocity in the mantle.

**Where the P wave velocity is highest?**

lower mantle

These waves are of relatively high frequency and are the least destructive among the earthquake waves. P-wave can travel in all mediums and their velocity varies according to the elasticity of the medium. The velocity of P-wave in Solid>Liquid>Gases. Its velocity is maximum in the lower mantle i.e. 13.5 km/s.

## What seismic waves travel faster P waves or S waves?

P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

### Which rock has highest P wave velocity?

The precise speed varies according to the region of the Earth’s interior, from less than 6 km/s in the Earth’s crust to 13.5 km/s in the lower mantle, and 11 km/s through the inner core….Velocity.

Rock Type | Velocity [m/s] | Velocity [ft/s] |
---|---|---|

Granite | 5,800–6,100 | 19,000–20,000 |

Gabbro | 7,200 | 23,600 |