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Flashcards in The Ocean Basin Deck (23):
1

What is the composition of Oceanic crust

silicate with iron (heavier)

2

What is the composition of Continental crust

silicate with aluminum (lighter)

3

What is another name for oceanic crust

basalt

4

what is another name for continental crust

granite

5

How old is the oldest oceanic crust

200 million years

6

How old is the oldest continental crust

3.8 billion years (since last rocks were melted)

7

What is the average thickness of oceanic crust

7 km

8

What is the average thickness of continental curst

40 km

9

What is Bathymetry

the topography of the sea floor

10

How much of the Earth surface is covered in water

71%

11

What is the mean depth of the ocean

3800 m

12

What is the continental shelf

gently sloping part of ocean floor adjacent to continent

13

What is the depth the shelf break is at

200 m

14

What is the slope of the continental crust

2 m for every 1 km traveled

15

What is the continental slope

zone between continental shelf and ocean basin

16

what is slope of continental slope

70 m for ever 1 km travled

17

What is turbidity

Suspended particles that decrease clairty

18

What is the continental rise

thick wedge of sediment located at base of continental slope

19

What is the abyssal plain

very flat region, has thick layer of sediment

20

What is the abyssal hills and seamounts

differs in height above sea floor, usually volcanoes, hills are extinct volcanoes

21

What are the mid ocean ridges and rises

volcanic subsea mountains that mark the region of crustal movement

22

What are trenches

steep sided depressions that mark where ocean crust is subducted into mantle
deepest part of ocean
often adjacent to volcanic island arcs

23

how do passive continental margins differ from active continental margins

passive- gentler slope, no volcanoes
active- steep slope, trench, volcanoes