GEOLOGY

Detailed explanation-1: -The first two wave types, P and S, are called body waves because they travel or propagate through the body of Earth. The latter two are called surface waves they the travel along Earth’s surface and their amplitude decreases with depth into Earth.

Detailed explanation-2: -Primary (P) and secondary (S) waves are two types of waves caused by earthquakes. They are defined based on when they arrive and are felt on the surface. P waves, or primary waves, arrive first while S waves, or secondary waves, arrive second. Both waves cause the ground to shake when an earthquake occurs.

Detailed explanation-3: -Surface waves, in contrast to body waves can only move along the surface. They arrive after the main P and S waves and are confined to the outer layers of the Earth. They cause the most surface destruction.

Detailed explanation-4: -P waves can become surface waves when they reach Earth’s surface. The Modified Mercalli scale rates the amount of damage from an earthquake. To locate the epicenter of an earthquake, geologists need data from two or more seismographs. In a seismograph, seismic waves cause the drum to vibrate.

Detailed explanation-5: -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. For example, if an earthquake occurs on one side of Earth, seismometers around the globe can measure the resulting S and P waves. SF Fig.