Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geol-1401 > Chapter 3 - Drifting Continents and Spreading Seas > Flashcards

Chapter 3 - Drifting Continents and Spreading Seas Flashcards

1
Q

Continental Drift?

A

Wegener proposed, instead, that the continents once fit together like pieces of a giant jigsaw puzzle, to make one vast supercontinent. He suggested that this supercontinent, which he named Pangaea (pronounced pan-jee-ah; Greek for all land), later fragmented into separate continents that drifted apart, moving slowly to their present positions ( Fig. 3.1 ). This model came to be known as continental drift .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

sea-floor spreading is?

A

The revolution began in 1960, when Harry Hess, of Princeton University, proposed that “as continents drift apart, new ocean floor forms between them” by a ‘process’ that his contemporary, Robert Dietz, also described and named sea-floor spreading .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

World War II, it became clear that earthquakes do not occur randomly, but rather

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

define distinct belts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

World War II, it became clear that earthquakes do not occur randomly, but rather

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

define distinct belts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where does movement of crust take place..

A

in bathymetric features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Research about the ocean floor in the mid-20th century provided clues that ultimately led to the proposal of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

sea-floor spreading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Studies of ocean floor bathymetry reveal the existence of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

abyssal plains, mid-ocean ridges, deep-sea trenches, and fracture zones.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Studies of ocean floor bathymetry reveal the existence of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

abyssal plains, mid-ocean ridges, deep-sea trenches, and fracture zones.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Volcanoes occur in arcs bordering trenches and on islands at the end of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

seamount chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Oceanic crust consists of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

basalt overlain by sediment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Oceanic crust consists of

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

basalt overlain by sediment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Heat flow increases toward the

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

axis of mid-ocean ridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Most earthquakes occur in

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

distinct belts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Hess proposed that ocean basins get wider with time by formation of new crust at mid-ocean ridges, a process called

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

sea-floor spreading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Old ocean floor slides back into the mantle at

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

trenches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Two continents move apart when sea-floor spreading occurs between them.

T OR F?

A

T!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Magnetic Anomaly

A

the difference between the expected strength of the Earth’s main dipole field at a certain location and the actual measured strength of the magnetic field at that location.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Magnetic Anomaly

A

the difference between the expected strength of the Earth’s main dipole field at a certain location and the actual measured strength of the magnetic field at that location.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Magnetic Reversals

A

Times when the Earth’s field flips from normal to reversed polarity, or vice versa,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Magnetic Reversals

A

Times when the Earth’s field flips from normal to reversed polarity, or vice versa,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When geologists compiled data from many cruises on a map, these ______ defined distinctive, alternating bands.

A

marine magnetic anomalies

22
Q

When geologists compiled data from many cruises on a map, these ______ defined distinctive, alternating bands.

A

marine magnetic anomalies

23
Q

magnetic-reversal chronology

A

Geologists applied the technique to determine the ages of rock layers in which they obtained their paleomagnetic mea-surements, and thus determined when the magnetic field of the Earth reversed. With this information, they constructed a history of magnetic reversals for the past 4.5 million years.

24
Q

magnetic-reversal chronology

A

Geologists applied the technique to determine the ages of rock layers in which they obtained their paleomagnetic mea-surements, and thus determined when the magnetic field of the Earth reversed. With this information, they constructed a history of magnetic reversals for the past 4.5 million years.

25
Q

The Earth behaves like a giant magnet, and thus is surrounded by a magnetic field. The magnetism is due to ..

A

the flow of liquid iron alloy in the outer core.

26
Q

The Earth behaves like a giant magnet, and thus is surrounded by a magnetic field. The magnetism is due to ..

A

the flow of liquid iron alloy in the outer core.

27
Q

Velocity =

A

Distance/Time

28
Q

Velocity =

A

Distance/Time

29
Q

Velocity =

A

Distance/Time

30
Q

Spreading Rate

A

means that a point on one side of the ridge moves away from a point on the other side by 2 cm per year.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

31
Q

In the Pacific Ocean, sea-floor spreading occurs at the…

A

East Pacific Rise. (Geographers named this a “rise” because it is not as rough and jagged as the Mid-Atlantic Ridge.)

32
Q

spreading rate for the East Pacific Rise is about 10 cm per year

T OR F

A

T

33
Q

spreading rate for the East Pacific Rise is about 10 cm per year

T OR F

A

T

34
Q

Glomar Challenger set out to sail around the ocean drilling holes into the sea floor. This amazing ship could lower enough drill pipe to drill in 5-km-deep water and could continue to drill until the hole reached a depth of about…

A

1.7 km (1.1 miles) below the sea floor.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

35
Q

Glomar Challenger set out to sail around the ocean drilling holes into the sea floor. This amazing ship could lower enough drill pipe to drill in 5-km-deep water and could continue to drill until the hole reached a depth of about…

A

1.7 km (1.1 miles) below the sea floor.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

36
Q

Though the case for drift has been greatly strengthened by the..

A

discovery of apparent polar-wander paths, it really took the pro-posal and proof of sea-floor spreading to make believers of most geologists.

37
Q

Though the case for drift has been greatly strengthened by the..

A

discovery of apparent polar-wander paths, it really took the proposal and proof of sea-floor spreading to make believers of most geologists.

38
Q

Though the case for drift has been greatly strengthened by the..

A

discovery of apparent polar-wander paths, it really took the proposal and proof of sea-floor spreading to make believers of most geologists.

39
Q

By relating the stripes on the Atlantic sea floor to mag-netic reversals found in basalt layers on land, geologists dated marine magnetic anomalies back to an age of…

A

4.5 million years…

40
Q

By relating the stripes on the Atlantic sea floor to mag-netic reversals found in basalt layers on land, geologists dated marine magnetic anomalies back to an age of…

A

4.5 million years…

41
Q

T or F? Earth’s magnetic field reverses polarity every now and then.

Copyright | W. W. Norton & Company | Earth: Portrait of a Planet (Fourth Edition) | charmsofgold@gmail.com | Printed from www.chegg.com

A

T

42
Q

T or F? Earth’s magnetic field reverses polarity every now and then.

A

T

43
Q

Measurements show that there are alternating stripes of positive and negative magnetic anomalies on the sea floor.

A

Measurements show that there are alternating stripes of positive and negative magnetic anomalies on the sea floor.

44
Q

Measurements show that there are alternating stripes of positive and negative magnetic anomalies on the sea floor.

A

positive and negative magnetic anomalies on the sea floor.

45
Q

Measurements show that there are alternating stripes of positive and negative magnetic anomalies on the sea floor.

A

positive and negative magnetic anomalies on the sea floor.

46
Q

Positive anomalies exist over sea floor formed when Earth’s magnetic field has normal polarity, whereas negative anomalies

A

exist over sea floor formed during chrons of reversed polarity.

47
Q

Positive anomalies exist over sea floor formed when Earth’s magnetic field has normal polarity, whereas negative anomalies

A

exist over sea floor formed during chrons of reversed polarity.

48
Q

Magnetic anomaly stripes on one side of a mid-ocean ridge are a mirror image of those on the other side, an observation compatible with …

A

the sea-floor spreading hypothesis.

49
Q

Magnetic anomaly stripes on one side of a mid-ocean ridge are a mirror image of those on the other side, an observation compatible with …

A

the sea-floor spreading hypothesis.

50
Q

Drilling shows that the age of the oldest sediment increases progressively away from the ridge, as predicted by ..

A

the sea-floor spreading hypothesis.

51
Q

Drilling shows that the age of the oldest sediment increases progressively away from the ridge, as predicted by ..

A

the sea-floor spreading hypothesis.

Geol-1401 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions