Surface ocean currents and the Coriolis effect
Grade 9 Science Worksheet

Circle the best answer.
NOAA: trade winds near 30° N blow from the northeast toward the southwest. Why not straight toward the equator, by Bo's reading?
- Mountains block it
- Ocean salt pushes the wind
- The Coriolis effect turns the air to the right
- The Coriolis effect turns it to the left
Wind pushing surface water offshore as cold water rises. NOAA: in downwelling, wind piles surface water against a coast. What does that water do, by Esme's reading?
- It freezes
- It rises, bringing nutrients up
- It sinks toward the bottom
- It flows uphill onto land
A current moving north in the Southern Hemisphere is deflected which way, by Jun's reading (NOAA)?
A globe with arrows curving right above the equator, left below. A globe with arrows curving right above the equator, left below. - To the right, toward the east
- Not deflected
- To the left, toward the west
- Straight down
Five gyres on a world map with their turning directions. Which way do Southern Hemisphere gyres turn, by Kira's reading (NOAA)?
- Clockwise
- Counterclockwise
- They do not turn
- They change direction each year
A gyre with a thick fast arrow on the west and a wide slow one on the east. A gyre with a thick fast arrow on the west and a wide slow one on the east. NOAA: the Gulf Stream is paired with another current to flank the North Atlantic gyre. Which, by Luz's reading?
- A gyre right on the equator
- A deep, cold, salt-driven current
- The Canary Current, a weak, broad eastern boundary current
- A second strong western boundary current
How does the Gulf Stream affect Florida's east coast, by Milo's reading (NOAA)?
Use the picture in question 5.
- Warmer winters and cooler summers than nearby states
- Colder winters than nearby states
- No effect on the coast
- Hotter summers than nearby states
A current arrow with a speed and a time beside it. A current arrow with a speed and a time beside it. speed time NOAA: the Gulf Stream travels 25 to 75 miles a day. How far could it carry a drifter in 10 days, by Noah's math?
- About 35 to 85 miles
- About 250 to 750 miles
- About 2,500 to 7,500 miles
- About 2.5 to 7.5 miles
NOAA: the Gulf Stream moves 1 to 3 knots, or 1.85 to 5.55 km/h. How far does it go in a day at 1.85 km/h, by Pia's math?
Use the picture in question 7.
- About 1.85 km
- About 4.4 km
- About 444 km
- About 44 km
At 5.55 km/h, about how many days would the Gulf Stream take to carry a drifter 1,000 km, by Ren's math?
Use the picture in question 7.
- About 180 days
- About 5,550 days
- About 7.5 days
- About 0.75 days
About how deep does the Ekman spiral reach, by Zee's reading (NOAA)?
Wind arrows over the surface and density arrows far below. Wind arrows over the surface and density arrows far below. surface wind arrows density arrows - Down to the sea floor
- About 1,000 m
- About 100 m
- About 10 m