Which of the following best describes the ocean surface layer?
A. zone of calm, slow-moving water
B. zone of turbulent mixing
C. zone of very dense, cool water
D. zone of low-salinity, dense water
Which statement best describes the difference between ocean surface currents and deep ocean currents?
A. Surface currents are cooler than deep currents because of the influence of wind.
B. Surface currents are driven by wind; deep currents are driven by density differences.
C. Surface currents are slow-moving; deep currents are fast-moving.
D. Surface currents are denser than deep currents.
Flat areas that occupy the deepest parts of the ocean floor are called the
A. abyssal plains
C. oceanic trenches
D. continental shelves
Where does most of the deep ocean water come from?
A. sinks from the North Atlantic
B. input from rivers and streams on the continents
C. upwelling from the Indian and Pacific Oceans
D. melting of polar ice sheets
What effect might the introduction of more freshwater into the North Atlantic have on global ocean circulation?
A. speed it up
B. stop it completely
C. block it and slow it down
D. make it flow in the opposite direction
What happens during El Nino years when coastal upwelling off the coast of South America is disrupted?
A. plankton populations flourish and fishing is very productive
B. plankton populations stay fixed but fish populations boom, creating imbalance in the ecosystem
C. plankton populations die off and fishers are put out of work
From which of the following do clouds form?
A. moisture evaporated from Earth
B. moisture from winds
C. water droplets from the upper atmosphere
D. air pollution
As the Gulf Stream travels north, it cools the air above it, making the climate of England cooler than it would be without the Gulf Stream.
Tundra is found in which climate zone?
Which of the following often takes place during El Nino?
A. drought in the western Pacific
B. high rainfall in the western Pacific
C. strengthening of trade winds in the south Pacific
D. ocean cooling
Large mountains can block the passage of moist air, making one side of the mountain receive more rain than the other.
Which layer of the atmosphere is very thick and is characterized by charged particles called ions?
In air the elements lead, cadmium, mercury and copper are examples of
A. radioactive pollutants
B. toxic metals