Home Chapter 12 Concept #2 Quiz

# Concept #2 Quiz

Choose the best possible answer to the following questions about Key Concept 2 "Earth's structure as revealed by seismic waves."

This activity contains 7 questions.

## Identify the indicated layers of Earth's interior and the type of seismic wave shown by selecting the correct response.

This question presents 7 items numbered 1.1 through 1.7. Each item is presented with a pulldown menu containing the letters A through G. For each item below, use the pull-down menu to select the letter that labels the correct part of the image.
1.1 asthenosphere A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G

## Why do seismic waves reach seismographs that are farther away from an earthquake BEFORE they reach closer ones? Choose all that apply.

 Waves that travel shallower are moving through rocks at lower pressure which makes the rocks more dense. The waves reaching the farther ones are augmented by other, closer earthquakes. Waves that travel deeper are moving through rocks at higher pressure which makes the rocks more dense. The waves reaching the farther stations have to travel through both the crust and the mantle (where rock is more dense). The waves reaching the closer stations traveled through the crust only.

## Why do seismologists conclude that the Earth must be composed of distinct shells having varying properties?

 Seismic waves passing below the crust are instantly slowed down until they stop at about 200 kilometers depth. Seismic waves passing through the deeper parts of the Earth change their type with depth. Seismic waves passing through the shallower parts of the Earth reflect off of the core. Seismic waves passing through the deeper parts of the Earth refract at distinct depths.

## The Earth’s core, mantle and crust are concentric shells. What major property is used to distinguish them?

 a. density, causing changes in seismic wave direction b. composition, causing changes in seismic wave direction both a. and b. neither a. nor b.

## Identify the indicated parts of the upper Earth by selecting the correct response. (Upper Earth diagram, Copyright © Prentice Hall, Inc.)

This question presents 7 items numbered 5.1 through 5.7. Each item is presented with a pulldown menu containing the letters A through G. For each item below, use the pull-down menu to select the letter that labels the correct part of the image.
5.1 continental crust A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G A B C D E F G

## Match the compositional layers of the Earth with the appropriate description:

A matching question presents 3 answer choices and 3 items. The answer choices are lettered A through C. The items are numbered 6.1 through 6.3. Screen readers will read the answer choices first. Then each item will be presented along with a select menu for choosing an answer choice. Using the pull-down menus, match each item in the left column to the corresponding item in the right column.
 solid, rocky shell that extends to a depth of about 2900 kilometers thin, varying in thickness from 3 to 70 kilometers iron-rich sphere having a radius of 3486 kilometers
6.1 core A B C A B C A B C

## Match the physical layers of the Earth with the appropriate description:

A matching question presents 5 answer choices and 5 items. The answer choices are lettered A through E. The items are numbered 7.1 through 7.5. Screen readers will read the answer choices first. Then each item will be presented along with a select menu for choosing an answer choice. Using the pull-down menus, match each item in the left column to the corresponding item in the right column.
 solid sphere of radius 1216 km where higher pressure keeps the hot metal solid “soft” layer below the lithosphere extending to a depth of 660 km “rigid” outermost layer consisting of the crust and the uppermost mantle; averages 100 km thick “rigid” lower mantle where increased pressure counteracts the effects of higher temperature liquid layer 2270 km thick that is the source of Earth’s magnetic field
7.1 inner core A B C D E A B C D E A B C D E A B C D E A B C D E