Deck 2: How We Study Earth

Question 1

Which of the following statements about the scientific method is not true?

A) A tentative explanation of a body of data is called a hypothesis.
B) Theories are less likely than hypotheses to be correct.
C) A hypothesis is strengthened if it successfully predicts the outcomes of new experiments.

Answer 1

B

Question 2

The ___ is the information preserved in rocks formed at various times throughout Earth history.

A) geologic data
B) geologic record
C) geodynamic information

Answer 2

B

Question 3

Which of the following is "a tentative explanation based on observational data and experiments"?

A) scientific theory
B) scientific hypothesis
C) scientific model
D) scientific thesis

Answer 3

B

Question 4

Complete the following sentence: A ________ is a representation of how a natural process operates or how a natural system behaves.

A) scientific theory
B) scientific hypothesis
C) scientific model
D) scientific thesis

Question 5

Scientific knowledge that has been elevated to the status of a scientific theory is no longer subject to change.

Question 6

Complete the following sentence: Scientific hypotheses should always be_______.

A) testable
B) correct
C) complex
D) simple

Question 7

The shape of the Earth is best described as

A) a perfect sphere.
B) near spherical with flattening at the equator and bulging at the poles.
C) near spherical with bulging at the equator and flattening at the poles.

Question 8

Which of the following techniques are used by geologists in their research?

A) creating computer models
B) laboratory experiments
C) observing the natural environment
D) all of these

Question 9

Geologic phenomena cannot be directly observed because geologic processes all operate over timescales much longer than a human lifespan.

Question 10

Which of the following phrases was used by James Hutton to summarize the Principle of Uniformitarianism?

A) Earth processes are uniform through time.
B) The present is the key to the past.
C) The laws of nature are unchangeable.
D) None of these.

Question 11

-Which part of the Earth depicted in the figure above is molten?

A) crust
B) mantle
C) outer core
D) inner core

Question 12

The temperature at which a rock melts generally ___ with increasing pressure.

A) increases
B) remains the same
C) decreases

Question 13

What are the two most abundant elements (by weight) in the whole Earth?

A) iron and oxygen
B) oxygen and silicon
C) silicon and iron

Question 14

What happens when seismic waves encounter a boundary between two materials?

A) All the wave energy bounces off the boundary.
B) All the wave energy passes through the boundary.
C) Some of the wave energy bounces off the boundary and some passes through the boundary.

Question 15

Beneath mountain belts, the Moho is

A) deeper than it is beneath normal continental crust.
B) shallower than it is beneath normal continental crust.
C) at the same depth as it is beneath normal continental crust.

Question 16

-Which region of the Earth consists primarily of iron and magnesium silicates?

A) region A
B) region B
C) region C

Question 17

Which of the following powers the Earth's internal heat engine?

A) radioactivity
B) heat trapped during the formation of the Earth
C) A and B
D) neither A nor B

Question 18

Which of the following Earth systems is powered by solar energy?

A) climate system
B) geodynamic system
C) plate tectonic system

Question 19

Which of the following statements about the lithosphere is not true?

A) The lithosphere is cool and relatively brittle.
B) The lithosphere includes the crust and uppermost mantle.
C) The lithosphere is easily deformed, like a tube of toothpaste.

Question 20

In a convecting system, like a pot of boiling water or the Earth's mantle,

A) cool material rises.
B) warm material rises.
C) both cool and warm material rise.

Question 21

Which of the following statements is correct?

A) The Earth's asthenosphere is much stronger than the lithosphere.
B) The Earth's asthenosphere is much weaker than the lithosphere.
C) The Earth's asthenosphere and lithosphere are similar in strength.

Question 22

Which of the following statements is correct?

A) biosphere system, atmosphere system, and hydrosphere system.
B) lithosphere system, asthenosphere system, and deep mantle system.
C) climate system, plate tectonic system, and geodynamic system.

Question 23

The geodynamo system is responsible for producing the Earth's

A) magnetic field.
B) convecting mantle.
C) weather.

Question 24

In the plate tectonic system, the lithospheric plates ride on the hot, weak ___ layer.

A) asthenosphere
B) deep mantle
C) outer core

Question 25

Which of the following rock types would be least likely to record the magnetic field at the time the rock formed?

A) basaltic lava flow
B) deep-sea shale
C) alluvial conglomerate

Question 26

The Earth has had a magnetic field for the last ___ years.

A) 5 million
B) 1 billion
C) 3.5 billion

Question 27

Which of the following statements is true?

A) The Earth's magnetic poles are aligned with its rotation axis.
B) The Earth's magnetic poles are inclined about 11° from its rotation axis.
C) The Earth's magnetic poles are inclined about 45° from its rotation axis.

Question 28

What is the lower mantle made up of?

A) dense silicate minerals
B) iron-nickel alloy
C) silicate melt

Question 29

Humans have been on Earth for ___ of Earth's history.

A) less than 1%
B) approximately 50%
C) more than 90%

Question 30

When did our solar system form?

A) about 540 million years ago
B) about 2.5 billion years ago
C) about 4.6 billion years ago

Question 31

Evidence in the rock record shows that there have been ___ major extinction events during Earth's history.

A) 10
B) 5
C) 2

Question 32

About when did the first animals evolve on Earth, according to current geological understanding?

A) 10 million years ago
B) 60 million years ago
C) 100 million years ago
D) 600 million years ago

Question 33

About when are Homo sapiens thought to have evolved?

A) 6000 years ago
B) 10,000,000 years ago
C) 200,000 years ago
D) 65,000,000 years ago

Question 34

How did Earth's atmosphere become oxygenated?

A) volcanic outgassing
B) gasses from asteroid impacts
C) radiation interacting with the atmosphere
D) oxygen-producing organisms

Question 35

Geologic evidence indicates Earth's moon and core formed within about the first 100 million years of Earth history.

Question 36

Approximately when did the mass-extinction event that led to the demise of the dinosaurs occur?

A) 50 thousand years ago
B) 443 million years ago
C) 1.4 billion years ago
D) 65 million years ago

Question 37

Which class of animals rose to dominance after the extinction of the dinosaurs?

A) amphibians
B) mammals
C) marine invertebrates
D) reptiles

Question 38

Earth's hydrosphere did not begin to form until at least 2 billion years ago.

Question 39

About what percentage of species went extinct during the largest mass extinction in Earth history?

A) 15%
B) 40%
C) 70%
D) 95%