What are P waves and S waves and where do they come from?

Asked by: Kathleen Jones

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.

What is P and S waves?

In P or compressional waves, the vibration of the rock is in the direction of propagation. 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.

Where do S waves come from?

S waves (in geology) Short for secondary waves, these are one of the types of seismic wave generated by earthquakes and underground explosions. S waves are a form of body waves, meaning they can move through Earth’s material and not just along the planet’s surface.

How do P waves and S waves travel?

P waves can travel through solids, liquids, and even gases. S waves shake the ground in a shearing, or crosswise, motion that is perpendicular to the direction of travel. These are the shake waves that move the ground up and down or from side to side.

What do P waves and S waves tell us?

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.

What S wave means?

An S wave, or shear wave, is a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is moving.

What are the P and S waves collectively called?

P and S waves together are sometimes called body waves because they can travel through the body of the earth, and are not trapped near the surface. A P wave is a sound wave traveling through rock.

What does P in a P wave mean?

Answer. The P wave represents atrial depolarization. The normal P wave morphology is upright in leads I, II, and aVF, but it is inverted in lead aVR.

What type of waves is P waves?

P Waves. P waves are compressional waves that do not produce much damage. They can move through any type of material and travel at almost twice the speed of S waves. High frequency P waves do not weaken, or “attenuate,” as rapidly as S waves so they retain higher frequencies when they arrive at seismic stations.

Where do S waves travel through?

S-waves are shear waves, which move particles perpendicular to their direction of propagation. They can propagate through solid rocks because these rocks have enough shear strength. The shear strength is one of the forces that hold the rock together, preventing it from falling into pieces. Liquids lack shear strength.

How do P and S waves differ from each other?

P and S waves are types of body waves. they differ from each other in speed. P-waves are the fastest waves that travel inside earth and can travel in all mediums. S- waves cannot travel in fluids as they dont have shear force.

What do P and S waves tell us about the earth interior?

Seismic waves tell us that the Earth’s interior consists of a series of concentric shells, with a thin outer crust, a mantle, a liquid outer core, and a solid inner core. P waves, meaning primary waves, travel fastest and thus arrive first at seismic stations. The S, or secondary, waves arrive after the P waves.

How do S waves travel through the earth?

S waves cannot pass through the liquid outer core, but P waves can. The waves are refracted as they travel through the Earth due to a change in density of the medium. This causes the waves to travel in curved paths.