Table of Contents
- 1 What happens at the Mohorovicic Discontinuity?
- 2 What happens to P waves at the Moho?
- 3 Do P waves travel through liquid?
- 4 How fast do P waves travel through granite?
- 5 What happens to S and P waves as they travel inside Earth?
- 6 Where do P waves travel the fastest?
- 7 What did Mohorovičić believe caused the second set of waves?
- 8 Where is the Moho discontinuity on the Earth?
What happens at the Mohorovicic Discontinuity?
The Moho marks the transition in composition between the Earth’s rocky outer crust and the more plastic mantle. This increase of approximately 1 km/s corresponds to a distinct change in material as the waves pass through the Earth, and is commonly accepted as the lower limit of the Earth’s crust.
What happens to P waves at the Moho?
Upon crossing the Moho from the crust to the mantle, P waves go faster in the mantle.
What happens to P waves and S waves from a crustal earthquake when the waves reach Earth’s outer core?
Figure 19.2a: P-waves generally bend outward as they travel through the mantle due to the increased density of mantle rocks with depth. When P-waves strike the outer core, however, they bend downward when traveling through the outer core and bend again when they leave. The bending of seismic waves is called refraction.
What is called Mohorovicic Discontinuity?
The Moho is the boundary between the crust and the mantle in the earth. Also termed the Mohorovicic’ discontinuity after the Croatian seismologist Andrija Mohorovicic’ (1857-1936) who discovered it. The boundary is between 25 and 60 km deep beneath the continents and between 5 and 8 km deep beneath the ocean floor.
Do P waves travel through liquid?
P and S waves travel through the planet Earth after an earthquake. Scientists studying the waves produced by earthquakes learned that Earth’s core has separate liquid and solid layers. S waves do not travel through liquid, but P waves do.
How fast do P waves travel through granite?
Velocity
| Rock Type | Velocity [m/s] | Velocity [ft/s] |
|---|---|---|
| Dolomite | 6,400–7,300 | 21,000–24,000 |
| Anhydrite | 6,100 | 20,000 |
| Granite | 5,800–6,100 | 19,000–20,000 |
| Gabbro | 7,200 | 23,600 |
What happened to the P waves when they are approaching?
When an earthquake occurs the seismic waves (P and S waves) spread out in all directions through the Earth’s interior. 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.
Why do P and S waves travel at different velocities?
P-waves and S-waves are body waves that propagate through the planet. P-waves travel 60\% faster than S-waves on average because the interior of the Earth does not react the same way to both of them. The energy is thus less easily transmitted through the medium, and S-waves are slower.
What happens to S and P waves as they travel inside 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. When the waves cross the boundary between two different layers, there is a sudden change in direction due to refraction. …
Where do P waves travel the fastest?
Sound waves are P-waves moving through the air. Because the earth’s mantle becomes more rigid and compressible as the depth below the asthenosphere increases, P-waves travel faster as they go deeper in the mantle. The density of the mantle also increases with depth below the asthenosphere.
What happens to the P waves when they are approaching to the molten part of the Earth’s interior?
P-waves bend slightly when they travel from one layer into another. Seismic waves move faster through denser or more rigid material. As P-waves encounter the liquid outer core, which is less rigid than the mantle, they slow down.
What is the Mohorovičić discontinuity?
What is the Mohorovičić Discontinuity? The Mohorovicic Discontinuity, or “Moho,” is the boundary between the crust and the mantle. The red line in the diagram shows its location. In geology the word “discontinuity” is used for a surface at which seismic waves change velocity. One of these surfaces exists at an average depth
What did Mohorovičić believe caused the second set of waves?
Mohorovičić knew that waves caused by earthquakes travel at velocities proportional to the density of the material carrying them. As a result of this information, he theorized that the second set of waves could only be caused by a sharp transition in density in the Earth’s crust, which could account for such a dramatic change in wave velocity.
Where is the Moho discontinuity on the Earth?
Earth’s crust and mantle, Moho discontinuity between bottom of crust and solid uppermost mantle. The Mohorovičić discontinuity (Croatian pronunciation: [moxorôʋiːt͡ʃit͡ɕ]), usually referred to as the Moho, is the boundary between the Earth’s crust and the mantle.
How did Mohorovicic use his discovery to study the thickness variations?
Mohorovicic was able to use his discovery to study thickness variations of the crust. He discovered that the oceanic crust has a relatively uniform thickness, while continental crust is thickest under mountain ranges and thinner under plains.