Ocean Currents - 6th Grade

1. What are the two main kinds of ocean currents? The two main kinds of ocean currents are surface currents and deep ocean currents. 

2. What three factors affect surface currents? The three factors that affect surface currents are global winds, the Coriolis effect, and continental deflections.

3. What is the major source of energy that powers ocean currents? The major source of energy that powers ocean currents is the sun.

4. What is the Coriolis effect? The Coriolis effect is the deflection of moving objects from a straight path because of Earth’s rotation.

5. What two factors affect the density of water currents? The two factors that affect the density of water currents are temperature and salinity. 

6. How do currents affect the climate of coastal areas? The currents affect the climate of coastal areas depending on the temperature of the water. Warm water heats the air and makes the air temperature warmer. Cold water cools the air and makes the air temperature cooler. 

7. What is El Niño? El Niño occurs when surface water temperatures in the central and eastern pacific become warmer than usual.

8. What is La Niña? La Niña occurs when surface water temperatures in the central and eastern pacific become cooler than usual.

9. What major effects can El Niño and La Niña cause? El Niño can cause flooding or droughts in different regions. La Niña can cause strong trade winds and more severe hurricane seasons.

10. What is upwelling? Upwelling is when warm surface water is replaced by cold deep water. The deep, nutrient-rich water rises toward the surface which is important for ocean life because nutrients support the growth of plankton.

11. What is continental deflection? When Earth’s continents and other landmasses influence ocean gyres.

  1. What is an ocean gyre? A large system of circular ocean currents formed by global wind patterns and forces created by Earth’s rotation.

  2. What are the 3 major types of ocean gyres? Tropical, Subtropical, and Subpolar.

  3. What are the 3 forces that cause the circulation of a gyre? Global wind patters, Earth’s rotation, and Earth’s landmasses

  4. What are ocean currents caused by? Tides and differences in density (caused by different temps and salinity)

  5. What helps drive the “ocean conveyor belt?” The movement of the world’s major ocean gyres, the continuous circulation of ocean currents, also known as thermohaline circulation.

  6. What is thermohaline circulation? A global system of deep-ocean currents driven by differences in water density caused by temperature (thermo) and salinity (haline). 

  7. What type of currents are deflected by Earth’s rotation (the Coriolis Effect)? Surface currents

  8. What type of currents are found at the ocean’s surface? Surface currents

  9. What type of currents are driven by the wind that blows across the water? Surface currents

  10. What type of currents make up the large ocean circulation systems? Deep ocean currents

  11. What type of ocean currents are driven by differences in temperature and salinity? Deep ocean currents

  12. Where does almost all rain come from? Evaporation from the ocean.

  13. What is salinity? The amount of salt in a body of water.

  14. Why are oceans important? Storing and transferring thermal energy, keeping global climate patterns stable, cycling gases and nutrients to marine ecosystems.

  15. What is the opposite of El Nino? La Nina.

  16. What weather conditions can El Nino cause? Flooding and droughts.

  17. What weather conditions can La Nina cause? Stronger than normal trade winds, cooler and drier weather, more severe hurricane seasons.