The Earth (10%)

Question 1

Which of the following best describes the principal way in which Earth’s atmosphere is heated?

(A) Heat flows from the center of Earth and is conducted through the ground to the air.
(B) The atmosphere absorbs short-wave radiation from the Sun as the Sun’s rays pass through it.
(C) Earth absorbs short-wave radiation from the Sun and radiates long-wave radiation, which is absorbed by the atmosphere.
(D) The air absorbs short-wave radiation from the Sun after the radiation has been reflected by the clouds.
(E) Warm air rises and cold air sinks and, as it sinks, is warmed by compression.

Answer 1

(C) Earth absorbs short-wave radiation from the Sun and radiates long-wave radiation, which is absorbed by the atmosphere.

Question 2

All of the following are true about air EXCEPT:

(A) It is mostly oxygen and carbon dioxide.
(B) Air is a mixture of different gases.
(C) Air density varies with temperature.
(D) Air contains water vapor.
(E) Air has a low heat capacity

Answer 2

(A) It is mostly oxygen and carbon dioxide.

Reason: Oxygen only makes up about 21% of air. About 78% of the air you breathe is made up of nitrogen (see graphic above).

Question 3

Most of Earth’s water exists in

(A) the oceans 
(B) the atmosphere 
(C) groundwater 
(D) lakes and rivers 
(E) polar ice caps

Answer 3

(A) the oceans

Reason: Oceans hold about 97% of Earth’s water.

Question 4

The study of which of the following would likely be the most helpful in providing information about the composition of Earth’s upper mantle?

(A) Temperatures of hot springs
(B) Size of vesicles in basalt flows
(C) Xenolith inclusions in igneous rocks
(D) Carbonate sediments from the ocean floor
(E) Minerals formed through contact metamorphism

Answer 4

(C) Xenolith inclusions in igneous rocks

Question 5

This atmospheric layer, or strata, is the closest to earth’s surface, extending 9 miles from the surface. It has the greatest density, and contains 99% of the water vapor in the atmosphere. Most weather is caused by the interactions of gases in this layer.

(A) Troposphere
(B) Stratosphere
(C) Mesosphere
(D) Thermosphere
(E) Exosphere

Answer 5

(A) Troposphere

Question 6

This atmospheric layer, or strata, extends 9 miles from the tropopause zone. The protective ozone (O3) layer that absorbs UV radiation is here.

(A) Troposphere
(B) Stratosphere
(C) Mesosphere
(D) Thermosphere
(E) Exosphere

Answer 6

(B) Stratosphere

Question 7

This atmospheric layer, or strata, is 30-50 miles above earth’s surface, with temperature decreasing outwards to as low as -110 degrees C. It has a very low density of gases, with almost no ozone or water.

(A) Troposphere
(B) Stratosphere
(C) Mesosphere
(D) Thermosphere
(E) Exosphere

Answer 7

(C) Mesosphere

Question 8

This atmospheric layer, or strata, is 50-300 miles above earth’s surface, with low gas density. The temperature in the _____ can rise as high as 1980 degrees C with the absorption of solar radiation by O2.

(A) Troposphere
(B) Stratosphere
(C) Mesosphere
(D) Thermosphere
(E) Exosphere

Answer 8

(D) Thermosphere

Question 9

This atmospheric layer, or strata, extends from the thermopause by about 620 miles. Due to its extremely low density of mostly hydrogen and helium particles and low gravitational forces, it is difficult to define.

(A) Troposphere
(B) Stratosphere
(C) Mesosphere
(D) Thermosphere
(E) Exosphere

Answer 9

(E) Exosphere

Question 10

All planets with atmospheres have _____, which is the name we give to the circulation of the atmosphere. The energy that powers the _____ is derived primarily from the sunlight that heats the surface. _____ on any planet represents the response of its atmosphere to changing inputs of energy from the Sun.

(A) Weather
(B) Climate
(C) Ultraviolet rays
(D) Ozone

Answer 10

(A) Weather

Question 11

_____ is a term used to refer to the effects of the atmosphere that last through decades and centuries.

(A) Weather
(B) Climate
(C) Ultraviolet rays

Answer 11

(B) Climate

Question 12

The earth itself is divided up into layers, either _____ (crust, mantle, and core) or _____ (lithosphere and asthenosphere).

(A) Rock, air
(B) Chemically, functionally
(C) Electrically, mantle

Answer 12

(B) Chemically, functionally

Question 13

The _____ is the entire outer surface of the earth, and is rich in oxygen, silicon, and aluminum.

(A) Crust
(B) Upper Mantle
(C) Mantle
(D) Outer Core
(E) Inner Core

Answer 13

(A) Crust

Question 14

The _____ is the middle layer of earth and accounts for 82% of the earths volume. It is thought to be rich in iron, magnesium, silicon, and oxygen.

(A) Crust
(B) Upper Mantle
(C) Mantle
(D) Outer Core
(E) Inner Core

Answer 14

(C) Mantle

Question 15

The mantle is _____ – it has the properties of a solid but flows like a liquid under high pressure.

(A) Rocky
(B) Plastic
(C) Aplastic
(D) Flexible

Answer 15

(C) Aplastic

Question 16

The _____ is the center layer of earth and is composed of mostly molten iron and nickel. The _____ itself has two zones – a liquid outer _____ and a solid iron inner _____.

(A) Crust
(B) Mantle
(C) Core

Answer 16

(C) Core

Question 17

The layers of earth can also be classified as the _____ and the _____.

(A) Lithosphere, asthenosphere
(B) Xenolith, mantle
(C) Mantle, core

Answer 17

(A) Lithosphere, asthenosphere

Question 18

This is composed of the crust and the rigid mantle layer.

(A) Lithosphere
(B) Asthenosphere

Answer 18

(A) Lithosphere

Question 19

This is composed of the molten plastic outer mantle of rock beneath the lithosphere.

(A) Lithosphere
(B) Asthenosphere

Answer 19

(B) Asthenosphere

Question 20

Many geologists study the mantle by analyzing _____. _____ are a type of intrusion—a rock trapped inside another rock.

(A) Mantles
(B) Cores
(C) Xenoliths

Answer 20

(C) Xenoliths

The xenoliths that provide the most information about the mantle are diamonds. Diamonds form under very unique conditions: in the upper mantle, at least 150 kilometers (93 miles) beneath the surface. Above depth and pressure, the carbon crystallizes as graphite, not diamond. Diamonds are brought to the surface in explosive volcanic eruptions, forming “diamond pipes” of rocks called kimberlites and lamprolites.
The diamonds themselves are of less interest to geologists than the xenoliths some contain. These intrusions are minerals from the mantle, trapped inside the rock-hard diamond. Diamond intrusions have allowed scientists to glimpse as far as 700 kilometers (435 miles) beneath Earth’s surface—the lower mantle.
Xenolith studies have revealed that rocks in the deep mantle are most likely 3-billion-year old slabs of subducted seafloor. The diamond intrusions include water, ocean sediments, and even carbon.