The Movement of Ocean Water

Although they flow near the top of the ocean, ______________________ can reach depths of several hundred meters.

• surface currents

• waves

• deep currents

• tides

Although they flow near the bottom of the ocean, _____________________ sometimes flow on top of other currents.

• deep currents

• surface currents

• tides

• waves

The negative effects of _____________________ include flash floods, mudslides and droughts.

• El Nino

• tsunamis

• La Nina

• upwelling

The ______________________ is used to measure wave periods and therefore wave speed.

• wavelength

• Coriolis effect

• tidal range

• wave height

The difference between levels of ocean water at high tide and low tide is called a(n) ______________________

• tidal range

• Coriolis effect

• upwelling

• undertow

How do changes in the circulation of ocean currents affect climate?

• by changing the atmosphere

• by moving water clockwise

• by increasing salinity

• by changing the tides

Which event does NOT happen as the result of an upwelling?

• Cold-water currents replace warm-water currents.

• Surface currents flow away from the shore.

• The California Current moves water south from the North Pacific.

• Plants get the minerals they need for photosynthesis.

Which of the following is most likely to spread pollution along the shore?

• upwelling

• breaker

• undertow

• longshore current

When do the greatest tidal ranges occur?

• spring tides

• neap tides

• high tides

• low tides

In 1947 Thor Heyerdahl sailed a simple raft from Peru to Polynesia, following the ocean currents for more than 6,000 kilometers. Which statement accurately describes what Heyerdahl proved by this voyage?

• Ancient Peru was settled by people from Polynesia.

• People from ancient Peru were the first settlers of Polynesia.

• It would have been possible for people from ancient Peru to reach Polynesia by following ocean currents.

• Polynesia was settled accidentally when rafts from Peru were carried out by ocean currents.