Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store

How do p waves move on the ground?

seo-qna
SearchIcon
Answer
VerifiedVerified
417k+ views
Hint: In an earthquake, the moving rock induces movements called seismic waves that move within or over the surface. To record data about seismic waves, scientists use an instrument called a seismograph. This data contains data that will help scientists learn not only about the behavior of earthquakes but also about the composition of the Earth itself.

Complete answer:
Two wide classes of seismic waves are available: body waves and surface waves. Inside the Earth's body, body waves fly. They contain waves of P or principal, and waves of S, or secondary.
P waves allow the earth to contract and expand in the direction of movement, that is, to pass back and forth. As they are the first type of wave to arrive at seismic recording stations, they are considered primary waves. Solids, liquids, and even gases can pass through P waves.
It pushes and pulls the surface, just as sound waves push and pull the air into it. Did you ever hear a huge clap of thunder and at the same time hear the windows rattle? The windows rattle because, just like P waves push and pull on the rock, the sound waves push and pull on the window glass.

Note: Owing to the pressing and pulling they do, P waves are also known as compressional waves. Subjected to a P wave, particles move in the same direction in which the wave passes, which is the direction in which the energy flows, and is often referred to as the 'wave propagation direction.