Geology Interlude D

The subdiscipline of geology that investigates the Earth's physical characteristics such seismic waves, gravity, and magnetism is termed _______.

geophysics

Which of the following best describes how scientists study the interior of the Earth?

Scientists use seismic waves, gravity, and magnetism to study the Earth's interior.

Seismic waves travel ________ in solids than in liquids; however, unlike P-waves, S-waves ________ travel through liquids.

faster; can't

If a P-wave is traveling through the Earth and encounters a molten magma chamber, what will happen to the velocity of the P-wave?

It will decrease.

If an S-wave is traveling through rock when it encounters a molten magma chamber, what will happen to the velocity of the S-wave?

It will not travel through the magma.

What behavior will seismic waves exhibit when traveling from a lower-velocity material into a high-velocity material?

The direction the waves are traveling will bend toward the boundary

Which layer of the Earth has the highest density?

core

The core consists of two layers: a(n) ________ inner core and a(n) ________ outer core.

solid; liquid

Using the graph below, why is the outer core liquid, but the inner core solid?

because the temperature in the inner core is below that of the melting curve

The graph below shows the change in velocity of seismic waves with depth in the crust. Why does the velocity of the P-wave drop drastically at the core-mantle boundary?

because the outer core is liquid and seismic waves travel slower in liquids

In the following graph, why does the line for S-waves NOT appear in the outer core?

S-waves can't travel through the outer core because it is liquid.

In the picture below, when the ship is filled with cargo it sinks into the water until the mass of water displaced is equal to the mass of the cargo. The ship is then said to be ________.

in isostatic equilibrium

The Earth's gravity is best represented by an equipotential surface that contains bumps and depressions where areas of higher or lower gravity appear over the Earth. This representation is called the ________.

geoid

A mountain range made of high-density basalt would produce a(n) ________ gravity anomaly compared to a mountain range of lower-density sedimentary rocks.

positive

The Earth's magnetic field is produced in the ________.

outer core

A positive magnetic anomaly is produced when the measured magnetic field strength is ________ the expected magnetic field strength.

stronger than

Why are magnetic anomalies of continental crust so much more complicated than those of oceanic crust?

The continents contain a complex distribution of igneous intrusions, lava flows, and iron-rich sediments.

The following image shows how a particular seismic wave will propagate through the Earth's interior. Using prior knowledge of seismic waves, how they travel, and the composition of the Earth's interior, what type of wave would produce the wave distribution shown below?

S-wave

The following image shows light entering standing water in a laboratory experiment. Which answer correctly matches the type of light with its location on the image?

A - refracted light, C - reflected light, B - incoming light

The image below shows how rays are either reflected or refracted as they pass from one medium to another. The materials differ in the speed at which rays can travel. Which statement BEST describes the effect of material speed on the rays?

A ray that enters a faster medium will refract toward the boundary between the two materials.

The image below shows light entering a water column in a laboratory experiment. Which statement BEST describes the experiment based on the schematics of how rays change as they transfer from one medium to another?

Light travels more slowly in water than in air.

The image below uses a cartoon ship to illustrate the idea of isostasy. Let's apply this concept to a real geologic problem. Based on the image below, what geologic process would be expected if a continent became loaded with glaciers?

subsidence