Geology Ch. 11

Information about the mantle comes primarily from:

Seismic wave velocities and mineral experiments.

Which is thought to change the composition of the outer core enough to produce convection?

Solidification of molten iron.

According to elastic rebound theory, earthquakes occur when:

Strain on a fault is released abruptly as the fault ruptures.

Most of the damage from earthquakes is caused by:

Surface waves.

Why do earthquake waves travel faster through the deep mantle than through the lithosphere?

The deep mantle is denser than the lithosphere.

The major current limitation of using seismic tomography to study mantle convection is:

The low resolution of the images produced.

Why are earthquakes less common in seismic gaps?

The rock on either side of the fault in a seismic gap is locked and stores rather than releases energy.

Which is the best description of seismic tomography?

The use of seismic ray paths to create three-dimensional images of Earth's interior.

Mantle tomography shows the presence of what are thought to be the remains of subducted slabs at the core-mantle boundary. These remains are known as:

Zones of low seismic velocity

Which method have scientists used to determine that most minerals that are stable on Earth's surface would not be stable within the mantle?

Laboratory experiments.

Seismic wave reflection has helped scientists identify:

The boundaries between the crust, mantle, and core.

Seismic tomography suggests that Earth's mantle exhibits:

A combination of different convection methods.

An earthquake occurs in San Francisco. Seismic waves from this earthquake are detected at a variety of seismographs worldwide. Information from which recording station would probably provide the most information about Earth's interior?

Beijing.

The general compositions, respectively, of the upper continental crust, lower continental crust, and ocean crust are:

Granite, diorite, basalt.

Which statement correctly describes Earth's interior?

It increases in density with depth.

How do scientists know that the outer core is not pure iron?

Its density is too low to be pure iron

Compared to an earthquake with a Richter magnitude of 4.0, an earthquake with a Richter magnitude of 8.0:

Produces 100,000 times as much ground motion.