Lesson 2: Circulation in
Earth’s Oceans
Ms. Overholt - Science 7
Popcorn reading
Each slide will have a textbook page(s) for the class to read.
Once we are finished reading the page, Ms. Overholt will show questions for
what you, as a student, need out of the text.
Write the responses to the question as a sentence for your notes. You do not
need to copy the question, just the answers.
The Formation of Surface Currents (p26-27)
1.
What is an ocean current?
An ocean current is the streamlike movement of ocean water in a regular
pattern
2.
What is a surface current?
A surface current is the horizontal movement of water in a regular pattern at
the ocean’s surface
3. What do you notice between the
direction of surface winds and the
direction of surface currents?
Surface winds and surface currents
move in the same directions/patterns.
Factors That Affect Surface Currents (p28)
1.
What are the 3 factors influencing surface currents?
3 factors influencing surface currents are: Global winds, Continental
Deflections, and The Coriolis Effect
2.
What are the huge circular patterns that Earth’s surface currents flow in?
Gyres are huge circular patterns that Earth’s surface currents flow in.
3.
Where does water drift because of the Coriolis effect?
Water drifts inwards toward the center of the gyres because of the Coriolis
effect.
Northern Hemisphere currents move clockwise, while Southern Hemisphere
currents move counterclockwise.
Hot and Cold Water (p30)
1.
Why is warm water less dense than cold water?
The warm water particles move faster and are more spread apart, becoming
less dense than cold water particles, despite being made the same.
Colors mixed
Colors stayed
in place
Cold water sank due to
being more dense
Warm water stayed on top
because it is less dense
Density Differences in Ocean Water (p32-33)
1.
What two properties of ocean water affect its movement?
Two properties of ocean water affecting its movement is salinity and
temperature
2.
What is the average salinity of all oceans?
35 g/L = the average salinity of all oceans
3.
How does temperature in the ocean change? Salinity?
Temperature changes by the absorption and release of solar energy. Salinity
changes because of precipitation, evaporation, addition of freshwater, and
formation of ice.
The Formation of Deep Currents (p34)
1.
Define deep ocean currents.
Deep ocean currents are the movement of water in regular patterns below the
surface of the ocean
2.
Why would water at the surface end up at the bottom of the ocean?
If the water becomes colder or increases in salinity, water at the surface will
sink.
3.
What are some factors that affect deep currents?
Some factors that affect deep currents include density differences and
gravity, continental location/deflection, and the Coriolis effect.
Earth’s Oceans as a System (p36-37)
1.
What are the 4 subsystems in Earth’s system?
Geosphere (the rocky part of Earth), Biosphere (the living things of Earth),
Atmosphere (the air around Earth), and Hydrosphere (all of Earth’s water)
Convection Currents in the Ocean (p37)
1.
Draw a diagram of a convection current (or convection cell) in the ocean.
Global Ocean Circulation (p38-40)
1.
How would the ocean have an important influence on weather and climate?
Due to energy transfers between the wind/air and surface water.
2.
What direction does energy, air, and water move?
Warm to cold
3.
What kind of matter is cycled because of water?
Dissolved solids, gases, marine organisms, pollutants
4.
Why is it important to cycle matter through water?
Chemical reactions and processes to take place, like photosynthesis and cellular
respiration