Ocean Currents and Tides - Practice Test 4

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.Which sea has the highest salinity?

   • A.Dead Sea✓ Correct Answer
   • B.Red Sea
   • C.Mediterranean Sea
   • D.Baltic Sea

   Explanation: Dead Sea (Lake) > Red Sea (Open Sea).

2. Q2.The ocean floor is mostly:

   • A.Abyssal Plain✓ Correct Answer
   • B.Continental Shelf
   • C.Trench
   • D.Ridge

   Explanation: Abyssal plains cover the largest area.

3. Q3.Continental Shelf is best for:

   • A.Fishing and Oil drilling✓ Correct Answer
   • B.Deep sea diving
   • C.Sailing
   • D.Surfing

   Explanation: Shallow water, sunlight, nutrients.

4. Q4.The deepest part of the Atlantic Ocean is:

   • A.Puerto Rico Trench✓ Correct Answer
   • B.Mariana Trench
   • C.Sunda Trench
   • D.Java Trench

   Explanation: Milwaukee Deep in Puerto Rico Trench.

5. Q5.Which current flows along the east coast of USA?

   • A.Gulf Stream✓ Correct Answer
   • B.California Current
   • C.Peru Current
   • D.Canary Current

   Explanation: Warm Gulf Stream.

6. Q6.Which current flows along the east coast of Japan?

   • A.Kuroshio✓ Correct Answer
   • B.Oyashio
   • C.Tsushima
   • D.California

   Explanation: Kuroshio (Warm).

7. Q7.The North Atlantic Gyre rotates:

   • A.Clockwise✓ Correct Answer
   • B.Anti-clockwise
   • C.Vertical
   • D.Random

   Explanation: Northern Hemisphere gyres are Clockwise.

8. Q8.The South Atlantic Gyre rotates:

   • A.Anti-clockwise✓ Correct Answer
   • B.Clockwise
   • C.Vertical
   • D.Random

   Explanation: Southern Hemisphere gyres are Anti-clockwise.

9. Q9.Ocean currents transfer heat from:

   • A.Equator to Poles✓ Correct Answer
   • B.Poles to Equator
   • C.West to East
   • D.Bottom to Top

   Explanation: Warm water moves poleward, regulating climate.

10. Q10.Cold currents generally flow on which side of continents in mid-latitudes?

    • A.West Coast✓ Correct Answer
    • B.East Coast
    • C.North Coast
    • D.South Coast

    Explanation: E.g., California, Canary, Benguela currents.

11. Q11.Warm currents generally flow on which side of continents?

    • A.East Coast✓ Correct Answer
    • B.West Coast
    • C.North Coast
    • D.South Coast

    Explanation: E.g., Gulf Stream, Kuroshio, Brazil currents.

12. Q12.Which sea has no coastline?

    • A.Sargasso Sea✓ Correct Answer
    • B.Red Sea
    • C.Black Sea
    • D.Caspian Sea

    Explanation: Defined by currents, not land.

13. Q13.The periodic daily rise and fall of sea level is caused by:

    • A.Attraction of Sun and Moon✓ Correct Answer
    • B.Earth rotation
    • C.Winds
    • D.Atmospheric pressure

    Explanation: Gravitational pull.

14. Q14.Tidal range is:

    • A.Difference between High and Low tide✓ Correct Answer
    • B.Distance travelled
    • C.Speed of tide
    • D.Depth of tide

    Explanation: Vertical difference in water level.

15. Q15.Drift is defined as:

    • A.Slow movement of water under wind influence✓ Correct Answer
    • B.Fast current
    • C.Tidal wave
    • D.River flow

    Explanation: e.g., North Atlantic Drift.

16. Q16.Stream is defined as:

    • A.Fast flowing volume of water like a river✓ Correct Answer
    • B.Slow drift
    • C.Tide
    • D.Lake

    Explanation: e.g., Gulf Stream.

17. Q17.Salinity decreases with:

    • A.Influx of river water / Rain✓ Correct Answer
    • B.Evaporation
    • C.Wind
    • D.Freezing

    Explanation: Freshwater dilutes the salt.

18. Q18.Salinity increases with:

    • A.High evaporation✓ Correct Answer
    • B.Heavy rain
    • C.Melting ice
    • D.River inflow

    Explanation: Water is removed, salt remains.

19. Q19.Which zone of the ocean gets sunlight?

    • A.Photic Zone✓ Correct Answer
    • B.Aphotic Zone
    • C.Abyssal Zone
    • D.Benthic Zone

    Explanation: Top layer (up to 200m).

20. Q20.Coral reefs are made of:

    • A.Calcium Carbonate✓ Correct Answer
    • B.Silica
    • C.Granite
    • D.Sand

    Explanation: Secreted by coral polyps.