What do you need to calculate the velocity of seismic waves? Definition of earth

Question

What do you need to calculate the velocity of seismic waves?

Definition of earthquake layers based on (1) seismology and (2) physical properties of rocks

How do tall and short buildings response to earthquakes?

What is asthenosphere?

What causes the jump in the P-wave velocity at 410 kilometers below the surface?

What causes melting in the asthenosphere?

What is hypocenter or focus?

What is epicenter?

How many scales are there in the Modified Mercalli Scale?

We calculated the P-wave velocity under Ohio using data from an earthquake in Canada. What was the P-wave velocity?

What is geothermal gradient?

What is tsunami? And what controls the height of tsunami waves?

Explanation / Answer

1.Velocity of seismic waves need to calculate, to know the composition and structure of the earyh's subsurface.

2. Because different types of earthquake waves behave differently when they encounter material in different states (for example,molten, semi-molten, solid. Earth's three major layers defined by chemical composition the crust, mantle, and core.

3. Tall buildings worse in earthquakes. Buildings made of brittle material like non reinforced concrete, brick or adobe.Shorter building wont' sway very much and tall buildings aren't affected by rapid ground movements. Medium sized buildings (5-15 stories) tend to sway at the same rate as the surface waves, causing the building to fail.

4. Asthenosphere is the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

5. Because of Transition zone at 410km . Transitions in a rock's mineralogy, but not in its chemical composition causing the jump in p wave velocity.

4.The material of which the asthenosphere is composed can be described as plastic-like, with much less rigidity than the lithosphere above it. This property is caused by the interaction of temperature and pressure on asthenospheric materials. Any rock will melt if its temperature is raised to a high enough temperature.

5. The hypocenter is the point within the earth where an earthquake rupture starts. The epicenter is the point directly above it at the surface of the Earth. Also commonly termed the focus.

6.Epicenter is the point on the earth's surface vertically above the focus of an earthquake.

7. Modified Mercalli Scale:A scale used for measuring an earthquake's intensity. It uses Roman Numerals from I to XII to describe increasing earthquake intensity levels.

8. 8.5 km/sec

9.Geothermal gradient is the rate of increasing temperature with respect to increasing depth in the Earth's interior. Away from tectonic plate boundaries, it is about 25–30 °C/km (72-87 °F/mi) of depth near the surface in most of the world.

10. Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.