Waves and Currents WarmUps

Which of these BEST describes the cause of waves in the ocean?

• high and low tides
• evaporation of water
• wind blowing across the surface of the ocean
• ridges and trenches on the bottom of the ocean

El Niño is an ocean current that is warmer than normal and recurs every few years in the Pacific Ocean. What effect would warmer waters have on weather along the Pacific Coast of the United States?

• More water would evaporate into the atmosphere and lead to more rain.
•  Less water would evaporate into the atmosphere and cause a drought.
• The air temperatures over land would decrease.
• The wind speeds over water would decrease.

What is the cause of most ocean surface currents? 

• gravity
• the wind
• the moon
• upwellings

When ice forms in the oceans, what happens to the water found directly underneath the newly formed ice?

•  it becomes colder
• it becomes warmer
• it becomes denser
•  it becomes more salty

A ________ is wind-powered movement of ocean water over great distances. 

• flood 
• current 
• trench 
• tornado

Currents caused by differences in water density are most often the result of 

• uniform temperature and salinity.
• differences in salinity and wind.
• uniform salinity and wind.
• differences in temperature and salinity.

A tsunami is an unusually large wave caused by

• an earthquake or volcano
• increased gravitational pulls when the sun and moon line up
• a heat wave
• extreme winds   

The two main parts of a wave are?

• Wavelengths and wave heights.
• Swells and whitecaps.
• Crests and troughs.
• Rises and dips.

The currents of the Earth's oceans are caused by 

• marine organisms and volcanic eruptions.
• global winds and differences in temperature and salinity.
• waves and earthquakes along tectonic plate boundaries.
• disturbances by submarines and large ships

Which of these is the most important function of the ocean?

• Giving off water vapor into the atmosphere.
• Warming up large nearby landmasses.
• Generating electricity.
• Place for people to swim.