AICE Ch. 4 Vocab. List

Question 1

Small sediment-covered in active volcano or intrusion of molten rock less than 200 meters (650 feet) hi, thought to be associated with seafloor spreading. It punctuates the otherwise flat abyssal plain.

Answer 1

Abyssal hill

Question 2

The continental margin near an area of lithospheric plate convergence; also called pacific-type margin.

Answer 2

Active margin

Question 3

The submerged outer edge of a continent, made of granite crust; includes the continental shelf and continental slope.

Answer 3

Continental margin

Question 4

The gradually sloping submerged extension of a continent, composed of granite rock overlain by sediments; has features similar to the edge of the nearby continent.

Answer 4

Continental shelf

Question 5

The point on Earth’s surface directly above the focus of an Earthquake.

Answer 5

Epicenter

Question 6

Flat topped, submerged inactive volcano.

Answer 6

Guyot

Question 7

One of several periods (lasting several thousand years each) of low temperature during the last million years. Glaciers and polar ice were derived from ocean water, lowering sea level at least 100 meters (328 ft.)

Answer 7

Ice age

Question 8

Deep-ocean floor made of basaltic crust, compare continental margin.

Answer 8

Ocean basin

Question 9

The continental margin near an area of lithospheric plate divergence; also called Atlantic-type margin.

Answer 9

Passive margin

Question 10

The abrupt increase in slope at the junction between continental shelf and continental slope.

Answer 10

Shelf break

Question 11

A plane along which rock masses slide horizontally past one another.

Answer 11

Transform fault

Question 12

An underwater “avalanche” of abrasive sediments thought responsible for the deep sculpturing of submarine canyons and a means of transport for sediments accumulating on abyssal planes.

Answer 12

Turbidity current

Question 13

Flat, cold, sediment-covered ocean floor between the continental rise and the oceanic ridge at a depth of 3,700 to 5500 meters (12,000 to 18,000 ft.). It is more extensive in the Atlantic and Indian oceans than in the Pacific.

Answer 13

Abyssal plains

Question 14

Deep-diving submersible designed like a blimp, which uses gasoline for buoyancy and can reach the bottom of the deepest ocean trenches.

Answer 14

Bathymetry

Question 15

The wedge of sediment forming the gentle transition from the outer (lower) edge of the continental slope to the abyssal plain; usually associated with passive margins.

Answer 15

Continental rise

Question 16

The sloping transition between the granite of the continent and the basalt of the seabed; the true edge of a continent.

Answer 16

Continental slope

Question 17

Area of irregular, seismically inactive topography marking the position of a once-active transform fault.

Answer 17

Fracture zone

Question 18

A spring of hot, mineral and gas-rich seawater found on same oceanic ridges in zones of active sea floor spreading.

Answer 18

Hydrothermal vent

Question 19

Curving chain of volcanic islands and seamounds almost always found paralleling the concave edge of a trench.

Answer 19

Island arc

Question 20

Young seabed at the active spreading center of an ocean, often unmasked by sediment, bulging above the abyssal plane. The boundary between diverging plates. Often called a mid ocean ridge, so less than 60% of the length exist at mid ocean.

Answer 20

Oceanic ridge

Question 21

A circular or elliptical projection from the sea floor, more than 1 kilometer (0.6 miles) in height, with a relatively sleep slope of 20° to 25°.

Answer 21

Seamount

Question 22

A deep, v-shaped valley running roughly perpendicular to the shoreline and cutting across the edge of the continental shelf and slope.

Answer 22

Submarine canyon

Question 23

An arc-shaped depression in the deep ocean floor with very steep sides and a flat sediment-filled bottom coinciding with a subduction zone. Most of them occur in the Pacific.

Answer 23

Trench