GEOLOGY

Detailed explanation-1: -Seismic waves travel at varying speeds when they pass through different types of matter. The composition of earth’s different layers is different. Therefore, when the seismic waves reach boundaries of rocks of the earth’s different layers, their speed and direction will change accordingly.

Detailed explanation-2: -Seismic waves move more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid. Partially molten areas may slow down the P waves and attenuate or weaken S waves.

Detailed explanation-3: -Both S and P waves travel faster through more dense material. Since density * increases with depth, waves speed up as they move deeper into the Earth. The change in density also causes the waves to follow curved paths as they move through the Earth. As waves travel into more dense material, they speed up and curve.

Detailed explanation-4: -The speed at which seismic waves travel depends on the properties of the material that they are passing through. For example, the denser a material is, the faster a seismic wave travels (SF Table 7.1). P waves can travel through liquid and solids and gases, while S waves only travel through solids.

Detailed explanation-5: -Seismic waves travel a curving path through the earth due to changes in composition, pressure, and temperature within the layers of the Earth. Seismic waves travel at different speeds through different materials. In this 2-layer model two wave fronts leave an impact at the same time but the lower layer is faster.