Chapter 13 Test: Oceans and Seas

About what percentage of the earth’s surface is covered by oceans?

• 71%

• 50%

• 35%

• 30%

Which ocean basin covers the largest percentage of the earth’s surface?

• Atlantic

• Arctic

• Indian

• Pacific

The mathematical model that approximates the earth’s average surface elevation is called the ____________.

• ellipsoid

• geoid

• projection

• local sea level

Island arcs are most often associated with ____________.

• A. oceanic trenches

• B. fracture zones

• C. continental shelves

• D. mid-ocean ridges

A Pacific Ocean atoll could have formed when

• a volcanic island collapsed into a flooded caldera on whose rim coral reefs grew.

• a shallow seamount sank or sea level rose above the seamount, forcing corals to grow upward from the crater rim and forming shallow reefs.

• either A or B happened.

• neither A nor B happened.

The most abundant salt found in ocean water is ____________.

• calcium sulfate

• magnesium bromide

• magnesium chloride

• sodium chloride

Which of the following gases is more abundant in the lighted zones near the surface than in the dark regions of the ocean?

• argon

• carbon dioxide

• nitrogen

• oxygen

While minerals constantly flow into an ocean, the ocean’s salinity rises only very slowly. Where do most of the minerals go?

• Organisms take minerals from the seawater.

• Minerals settle out of the water, forming sediments.

• Minerals evaporate along with the water from the ocean.

• both A and B

Seawater temperature near the ocean bottom

• is much warmer near the Equator than near the North Pole.

• varies widely all over the world.

• varies little all over the world.

• is about the same as it is near the surface.

How does the temperature, pressure, and density of water typically change as you ascend from the floor of the ocean to the surface?

• Temperature decreases, pressure decreases, and density increases.

• Temperature increases, pressure increases, and density increases.

• Temperature increases, pressure decreases, and density decreases.

• Temperature decreases, pressure increases, and density increases.