Underwater Features

Question 1

Continental Shelf

Answer 1

Submerged, extended perimeter of the continent once exposed during glacial periods.

Question 2

Continental slope

Answer 2

A steep slope separating the continental shelf from the deep ocean basin.

Question 3

Submarine Canyon

Answer 3

A steep – sided valley cut into the sea floor of the continental shelf.

Question 4

Abyssal Plain

Answer 4

An underwater plain on the deep ocean floor between the continental rise in mid-ocean ridge. Abyssal plains cover more than 50% of the seafloor.

Question 5

Abyssal Hill

Answer 5

Low, rounded hills less than 100 m high on the abyssal plain.

Question 6

Guyot

Answer 6

Flat topped volcano which has subsided beneath the water surface.

Question 7

Sea Mount

Answer 7

Underwater volcano which is not reached the water surface.

Question 8

Island

Answer 8

A relatively small land area surrounded by water. Some islands are extensions of the oceanic crust that extends above the surface. Others are part of the continental lithosphere.

Question 9

Trench

Answer 9

Long, narrow, deep depression in the seafloor associated with a subduction zone of two converging plates. Location where the crust is destroyed/melted.

Question 10

Mid – Ocean Ridge

Answer 10

An underwater mountain system created by a Rift Valley between two diverging plates. Location where new crust is formed; also the site of seafloor spreading.

Question 11

Continental crust

Answer 11

Mostly comprised of granite and has a density of 2.7 g/cm³ which makes it less dense than the mantle and the oceanic crust. Continental crust is thicker than oceanic crust.

Question 12

Oceanic crust

Answer 12

Comprised of basalt & has a density of about 2.9 g/cm³ making it denser than continental crust. When converging with a continental plate, and oceanic plate will sink. Oceanic crust is thinner than continental crust.