How do P waves and S waves travel?
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. The different S waves arrive after the P waves.
Where do S waves travel?
S waves move rock particles up and down, or side-to-side–perpendicular to the direction that the wave is traveling in (the direction of wave propagation).
Why do S waves not travel through liquid?
S-waves cannot travel through liquids. When they reach the surface they cause horizontal shaking. Liquids don’t have any shear strength and so a shear wave cannot propagate through a liquid. Think of a solid material, like a rock.
Why can’t s waves pass through the outer core?
Shear waves cannot travel in liquids or gases — so, for example, S waves don’t travel through the ocean or through the outer core. Surface waves are called surface waves because they are trapped near the Earth’s surface, rather than traveling through the “body” of the earth like P and S waves.
What happens to S waves when they reach the outer core?
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.
Why do S waves stop at the outer core?
The bending of seismic waves is called refraction. 6. Figure 19.2b: S-waves do not travel through the outer core, creating an even bigger shadow zone for S-waves. The fact that S-waves do not travel through the outer core suggests that the latter is liquid.
What is the speed of S and P waves in the outer core?
Typical values for P wave velocity in earthquakes are in the range 5 to 8 km/s. The precise speed varies according to the region of the Earth’s interior, from less than 6 km/s in the Earth’s crust to 13.5 km/s in the lower mantle, and 11 km/s through the inner core.
What did seismologists infer when they didn’t see the shear S waves in the outer core?
We do not see shear (S) waves passing through the outer core. Because liquids can not be sheared, we infer that the outer core is molten.
What did seismologists infer when they didn t?
Answer. Answer: We do not see shear (S) waves passing through the outer core. Because liquids can not be sheared, we infer that the outer core is molten.
When seismic waves slow down what does it indicate?
Low Velocity Zone Furthermore, while both the P and S waves travel more slowly, the S waves are attenuated or weakened. This is interpreted to be a zone that is partially molten, probably one percent or less (i.e., greater than 99 percent solid).
What is it called when a seismic wave bends as it passes from liquid to solid rock?
What is it called when a seismic wave bends as it passes from liquid to solid rock? Refraction.
What are signs of activity in Earth’s interior?
Q: What are signs of activity in Earth’s interior? A: Answers will vary, but two possibilities are volcanic eruptions and earthquakes.