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
- The Coriolis effect turns it to the left
- The Coriolis effect turns the air to the right
- Ocean salt pushes the wind
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 sinks toward the bottom
- It rises, bringing nutrients up
- It flows uphill onto land
- It freezes
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. - Not deflected
- Straight down
- To the left, toward the west
- To the right, toward the east
How does the Gulf Stream affect Florida's east coast, by Milo's reading (NOAA)?
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. - Hotter summers than nearby states
- Colder winters than nearby states
- Warmer winters and cooler summers than nearby states
- No effect on the coast
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 2,500 to 7,500 miles
- About 2.5 to 7.5 miles
- About 250 to 750 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 5.
- About 44 km
- About 1.85 km
- About 444 km
- About 4.4 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 5.
- About 7.5 days
- About 5,550 days
- About 0.75 days
- About 180 days
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 NOAA: in the Ekman spiral, each deeper layer moves more slowly and is deflected farther. Which way do the deeper layers turn in the Northern Hemisphere, by Tala's reading?
- Straight down
- Faster than the surface layer
- Farther to the left
- Farther to the right
About how deep does the Ekman spiral reach, by Zee's reading (NOAA)?
Use the picture in question 8.
- About 100 m
- About 10 m
- Down to the sea floor
- About 1,000 m
Wind pushing surface water offshore as cold water rises. Wind blows surface water away from a coast (NOAA). What happens next, by Ari's reading?
- Fresh river water fills the gap
- Cold, nutrient-rich water wells up from below
- Warm water sinks, and the coast warms
- Sea level rises at the coast