L4. STRUCTURE AND EVOLUTION OF OCEAN BASINS AND THE PLATE TECTONIC THEORY

Question 1

This caused the formation of different topographic features.

Answer 1

Seafloor Spreading

Question 2

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

An area with shallow water that surrounds the land(continent).

Answer 2

Continental Shelf

Question 3

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

It is the border of the continental shelf. It is the submerged outer edge of the continent where continental crust transitions into oceanic crust.

Answer 3

Continental Margin

Question 4

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

It is sometimes referred to as the seafloor. An extremely vast flat surface underwater, that is sometimes interrupted by hills, seamount and valleys.

Answer 4

Abyssal Plain

Question 5

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

These are elongated hills, typically 50-300m high and common on the slopes of mid oceanic ridge

Answer 5

Abyssal Hill

Question 6

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

It is a submarine mountain chain that winds for more than 65,000 km around the globe. It has a central rift valley and rugged topography on its flanks.

Answer 6

Mid-ocean Ridges

Question 7

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

These are narrow, elongated depressions on the seafloor many of which are adjacent to arcs of island with active volcanoes; deepest features of the seafloor

Answer 7

Deep-ocean Trenches

Question 8

TOPOGRAPHIC FEATURES OF THE SEAFLOOR

Submerged volcanoes are called ____________ while those that rise above the ocean surface are called ___________ __________. These features may be isolated or found in clusters or chains.

Answer 8

Seamounts; Volcanic Islands

Question 9

Any of several vast submarine regions that collectively cover nearly three-quarters of Earth’s surface.

Answer 9

Ocean Basin

Question 10

EVOLUTION OF THE OCEAN BASIN

The formation of the ocean basin starts with a rifting of a continental crust. A continent may split and forms a rift valley.

Answer 10

Embroyonic Stage

Question 11

EVOLUTION OF THE OCEAN BASIN

In this stage, basalt which comes from the molten material oozing from the rift will start to form the seafloor.

Answer 11

Juvenile Stage

Question 12

EVOLUTION OF THE OCEAN BASIN

In this stage, the ocean basin continues to widen. At some point its boundary, will meet with continental crust that will start its subduction on the other side.

Answer 12

Mature Stage

Question 13

EVOLUTION OF THE OCEAN BASIN

As the movement of the plates may change, ocean basins may start to narrow. The origin, which are diverging plates may end up to be converging with other plates that will permit the narrowing of the ocean floor.

Answer 13

Terminal

Question 14

EVOLUTION OF THE OCEAN BASIN

The last stage of ocean basin evolution ends with the complete collision of two continental plates. The last seafloor will be eliminated and a previously formed ocean basin will no longer be seen as mountain chains replaces it

Answer 14

Continental Collision