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Flashcards in Quiz 1 Deck (30)
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0

why does the surface of earth remain constant throughout time?

subduction occurs
rates of sea-floor spreading are equal to sea floor consumption

1

deep ocean trenches are features of ________-plate boundaries

convergent

2

summed over the entire surface of earth ________

rates of lithospheric production and consumption are equal

3

the youngest sea floor occurs ______

along mid ocean ridges

4

why don't earthquakes occur everywhere?

rocks break and slip most often along plate boundaries
plate interiors do not accommodate much movement

5

tectonic plates move at rates that are approximately ______

1-15 cm/yr

6

tectonic plates might consist of _________

oceanic or continental lithosphere, or a combination of both

7

the theory of plate tectonics incorporates and explains ______

both sea floor spreading and continental drift

8

under the theory of plate tectonics, the plates themselves are ________

discrete pieces of lithosphere at the surface of the solid earth that move with respect to one another

9

t/f in a hot-spot volcanic island chain, such as the Hawaiian Islands, all islands posses active volcanoes simultaneously and therefore the risks of volcanic hazards are about the same for all islands

false

10

continental lithosphere is ______

thicker than oceanic lithosphere

11

marine magnetic anomaly belts run parallel to _____

mid ocean ridges

12

the oldest rocks on the ocean floor are about ________ years old

200 million

13

deep ocean trenches are found predominantly along the perimeter of the ______ and can reach depths up to ______, deep enough to swallow mt. everest

Pacific Ocean; 8-12 km

14

the age of oceanic crust _____ with increasing distance from mid ocean ridge

increases

15

t/f the deep ocean floor is flat and nearly featureless

false

16

the magnetic field of earth in geologic past is known to have ______

experienced numerous polarity reversals, due to remnant magnetization of iron rich minerals in rocks

17

in wegener's evidence for continental drift, continets were proposed to fit together, such as the east coast of South America with ______ and the upper west coast of Africa with the _______

lower west coast of africa; east coast of North America

18

the theory of plate tectonics is a theory becaise ______

it is commonly regarded as correct

19

without plate tectonics we would not have ______

plates in constant
mountain building
formation of new oceans

20

the distinction between the crust and the mantle is primarily on the basis of a difference ______; the distinction between the lithosphere and the asthenosphere is primarily on the basis of a difference in _____

chemistry; degree of physical rigidity

21

the lithosphere is directly above the _____

asthenosphere

22

the thickness of the earths crust varies from ____

7-70 km

23

as compared to the rocks that make up the crust, earth as a whole is _____

considerably more dense

24

earths geothermal gradient is the rate of temperature change that would occur if one could move in which of the following ways?

traversing down within earths interior

25

earths magnetic field is generated by the ____

the flow of the outer core

26

earths surface is protected from solar wind andd cosmic radiation by _____

the earths magnetic field

27

the shape of the earths magnetic field is approximately that of a ____

dipole

28

the metal alloy that makes up the core of earth is ________ as compared to the rocky mantle

denser

29

list the steps of the scientific method

1. problem
2. observation
3. experiment
4. conclusion
5. repeat, refine, reject