Marine Province

Question 0

Passive continental margins

Answer 0

Lacks a plate boundary

Low degree of plate tectonic activity

Question 1

3 major ocean floor provinces

Answer 1

Continental margins
Deep ocean basins
Mid ocean ridge

Question 2

Active continental margin

Answer 2

High degree of tectonic activity

Includes convergent active margins and transform active margins

Question 3

Continental shelf

Answer 3

Generally flat zone extending form the shore beneath the ocean surface to the shelf break

Question 4

Shelf break

Answer 4

A point at which a marked increase in slope angle occurs

Question 5

Continental shelf average width and range in km

Answer 5

70 km but varies to 1500 km

Question 6

Shelf break average depth in meters

Answer 6

135m

Question 7

Continental slope

Answer 7

Lies beyond shelf break and is where’s the deep ocean basins begin

Question 8

Which North American continental margin has a continental slope with a steeper average gradient

Answer 8

Pacific margin

Question 9

Submarine canyons

Answer 9

Narrow nut deep submarine valleys that are V shaped in profile view and have branches or tributaries with steep over hanging walls

Question 10

Constrast the size of the Monterey Submarine Canyon and the Grand Canyon

Answer 10

Comparable in size in terms of length width and steepness

Question 11

Average depth of continental slope

Answer 11

3500m below sea level

Question 12

Why the portions of submarine canyons below a few hundred meters could not have formed by stream erosion

Answer 12

Many are not directly offshore where rives enter the the sea and many are confined to the continental slope

Question 13

Contrast the shapes of submarine canyons confined to the continental slope to canyons that cut across the continental shelf

Answer 13

Canyons confined to the continental slope have straighter and steeper canyon floor gradients

Question 14

Explain the formation of most submarine canyons

Answer 14

Turbidity currents

Question 15

Turbidity currents

Answer 15

Underwater avalanches of muddy water mixed with sediments that move down the continental slope

Question 16

Triggering mechanisms for turbidity currents

Answer 16

Shaking by earthquake
Overstepping of sediment that accumulates on the shelf
Hurricanes passing over the sea
Rapid input of sediment from flood waters

Question 17

Continental rise

Answer 17

Transition zone between the continentals margin and the deep ocean floor comprised of huge submerges piles of debris

Question 18

Formation of continental rise

Answer 18

When a turbidity current moves through and erodes a submarine canyon, it exits through the mouth of the canyon. The angle of the slope decreases and the turbidity current slows down causing the material to settle

Question 19

How grade bedding sequences in continual rises form

Answer 19

As the energy of the turbidity current dissipates in a submarine canyon, the larger pieces settle first, then progressively smaller pieces settle, and eventually the very fine pieces settle out.

Question 20

Deep sea fan

Answer 20

The deposits at the mouths of submarine canyons that are fan shaped

Question 21

Role of deep sea fans in the formation of continual rise

Answer 21

They create the continental rise when they merge together along the base of the continual slope

Question 22

Why continental rise often do not form along active continental margins

Answer 22

The steep continental slope leads directly into a deep ocean trench. Sediments from turbidity currents accumulates km the trench causing failure in continental rise

Question 23

Indus deep sea fan’s length

Answer 23

1800 km