Ch. 14 Ocean Motions

What usually has the greatest influence in causing tides?

• the earth's core

• the moon

• the sun

• the weather

How many tides do most coasts experience in a typical 24-hour period?

• one low and one high

• two lows and one high

• one low and two highs

• two lows and two highs

The very high tides that occur twice a month are caused by

• the sun, moon, and earth being arranged in a straight line.

• the sun and moon being arranged at right angles to the earth.

• the Coriolis effect.

• shifting surface currents.

If you wanted to sail around the globe by wanted to remain south of Africa and South America, what single current could you use to speed up your trip?

• Peru Current

• Atlantic Current

• Antarctic Circumpolar Current

• South Equatorial Current

The major warm current located in the West Atlantic Ocean is the

• Bermuda Current.

• Humboldt Current.

• Canary Current.

• Gulf Stream.

Which of these combines the effects of the Coriolis effect, current speed, and water depth to produce the direction of a current?

• coastal downwelling

• density currents

• Ekman spiral

• oscillation

Which of these forms of sea life are though to take advantage of ocean currents in their efforts to move about?

• European eels

• humpback whales

• plankton

• all of these

In the center of an ocean gyre, the sea level is usually

• higher than outside the gyre.

• lower than outside the gyre.

• the same level as outside the gyre.

• unrelated to the level outside the gyre.

Water that is forced down by downwelling typically has ___ than surrounding waters.

• more nutrients but less oxygen

• more oxygen but less nutrients

• more nutrients and more oxygen

• less nutrients and less oxygen

Which of these would have the least effect on subsurface currents?

• downwelling

• Ekman spiral effect

• prevailing winds

• density differences