Water circulation

Which of the following would be the best choice to model what drives surface ocean currents?

• a tank of water with a block of ice attached to one end

• a tank of water with a fan blowing over the surface of the water

• a system of pipes with a heater at one end

• a tank of water with a heater under the tank

Rain falls into the ocean and the density of ocean water ...

• decreases

• increases

Ocean water becomes colder and the density of ocean water ....

• decreases

• increases

A river empties into the ocean and the density of ocean water ....

• decreases

• increases

The map shows the surface temperature of the Gulf Stream and the ocean water farther north. Where are deep currents most likely to be forming as water from the surface sinks?

• south of 30° north latitude

• between 30° and 35° north latitude

• between 35° and 40° north latitude

• north of 40° north latitude

Which statement explains why the water in the South Pacific gyre begins to warm up as it moves away from the coast of South America?

• It receives more energy from the sun.

• It receives more rainfall from the atmosphere.

• It loses more heat energy to the atmosphere.

Ocean water in the (a)___________ Peru Current is deflected by the continent of (b)_____________ and then joins the South Equatorial Current.

• a. cold

• a. warm

• b. Australia

• b. South America

Energy enters the Earth system from the ....

• sun

• moon

Some of that energy is absorbed by Earth’s atmosphere. Because the warming of Earth's surface and the atmosphere is uneven, areas of high and low_____________form, which cause wind in the atmosphere.

• visibility

• humidity

• pressure

When the wind blows across the ocean surface, some of the kinetic energy from the wind is transferred to the ocean water. The kinetic energy transfer causes the ocean water to move as .......

.

• deep currents

• convection currents

• surface currents