8 EW Ch 4-1 Exploring the Ocean

1) A technique that uses sound waves to measure the depth of the ocean floor is

• dredging.

• sonar.

• SCUBA.

• weighted lines.

2) Which of the following does NOT make studying the ocean floor difficult?

• The ocean consists of salt water rather than fresh.

• The deep ocean is in total darkness.

• The water in the deep ocean is extremely cold.

• There is tremendous pressure in the deep ocean.

3) A nearly flat region of the ocean floor, covered with thick layers of sediment, is called a(n)

• seamount.

• abyssal plain.

• continental slope.

• mid-ocean ridge.

4) A deep canyon in the ocean floor is called a(n)

• abyssal plain.

• seamount.

• trench.

• continental shelf.

5) Which of the following features of the ocean floor forms where two plates diverge?

• seamount

• trench

• abyssal plain

• mid-ocean ridge

6) Sea-floor spreading occurs in places where two plates are

• converging.

• diverging.

• motionless.

• breaking the surface.

7) Hot liquid from Earth’s mantle is called

• magma.

• the crust.

• the plates.

• the core.

9) Which letter identifies the continental shelf?

• a

• b

• c

• d

• e

10) What is at C?

• Sea Mount

• Mid Ocean Ridge

• Abyssal Plain

• Trench

11) What is at D?

• Sea Mount

• Mid Ocean Ridge

• Abyssal Plain

• Trench