Question

Consider the below statements with respect to seismic waves.
1. S-waves does not pass through a fluid.
2. P-waves pass through a fluid.
Identify the correct statement:
1. Statement 1 is false and statement 2 is true
2. Statement 1 is true and statement 2 is false
3. Both are false
4. Both are true

Answer 1

Correct Answer - Option 4 : Both are true

Explanation:

Seismic waves:

Seismic waves or vibrations originate from the focus and are propagated in all directions. These vibrations travel through the rocks in the form of elastic waves. Mainly three types of waves called P wave, S wave, and L wave.

P waves:

These are primary waves (longitudinal or pressure waves). These are the fastest among the seismic waves. They travel as fast as 8-13 km/sec depending upon the density and elasticity of the medium. Therefore, when an earthquake occurs, these are the first wave to reach any seismic station and hence the first to be recorded. These waves are capable of travelling through solids, liquids and gases.

S waves:

These are called shear waves, transverse waves. As compared to P waves these are relatively slow. They travel at the rate of 5-7 km/sec. These waves are capable of travelling only through solid.

L waves:

These are called long waves or surface waves. These are the slowest among the seismic waves. Therefore these are the last to be recorded. They travel at the rate of 4-5v km/sec. These waves are capable of traveling through solids and liquids. The destruction at the time of the earthquake is caused by these waves only. These waves do not travel towards the interior of the earth from the focus. They are of 2 types - Rayleights and Love waves.