Physiography Of The Ocean Floor

Question 1

What are the components of a continental margin?

Answer 1

Shelf
Shelf break
Slope
Rise

Question 2

What is the shelf like in a continental margin?

Answer 2

Nearly flat, 1-1000km wide, 0.5 degree slope

Question 3

What is the shelf break like in a continental margin?

Answer 3

130m depth, 1-4 degrees

Question 4

What is the slope like in a continental margin?

Answer 4

4 degree slope to 2/3km depth, submarine canyons

Question 5

What is the rise like in a continental margin?

Answer 5

1 degree slope to 500km offshore and 4km depth

Question 6

What are the components of deep ocean basins?

Answer 6

Abyssal plain
Abyssal hills
Seamounts
Deep sea trenches

Question 7

What is the abyssal plain like in a deep sea basin?

Answer 7

3-5km depth, land derived sediment, 100-1000km thick

Question 8

What are the abyssal hills like in deep sea basins?

Answer 8

<1000m high, 100m-100km wide, volcanic rocks

Question 9

What are the seamounts like in deep ocean basins?

Answer 9

Extinct/active volcanos, >1000m high, guyots

Question 10

What are the deep sea trenches like?

Answer 10

Long narrow depressions, 3-5km deep, seismic

Question 11

What are the components of mid ocean ridges?

Answer 11

Continuous mountain belts, >60000km long, 1/3 of ocean floor, geologically active, frequent shallow earthquakes, faulting, volcanism.

Question 12

Continents vs Ocean basins

Answer 12

Continents - 29% of surface mean height (0.84km), granitic rocks, igneous (O, Si, Al), 2700kg/m3, 30-40km thick
Ocean basins - 71% of surface mean depth (3.8km), basaltic rocks, volcanic (O, Si, Mg), 2900kg/m3, 4-10km thick.