The Ocean Currents

Total Questions: 21

1. Consider the following factors [I.A.S. (Pre) 2012]

1. Rotation of the Earth

2. Air pressure and wind

3. Density of ocean water

4. Revolution of the Earth

Which of the above factors influences the ocean currents?

Correct Answer: (b) 1, 2 and 3
Solution:Ocean current is a continuous, directed movement of seawater generated by forces such as rotation of the earth, wind, temperature and salinity difference, air pressure, sea water density difference etc. Revolution of the earth does not influence the ocean currents. Hence, option (b) is the correct answer.

2. Consider the following statements: [I.A.S. (Pre) 2002]

1. Ocean currents are the slow-surface movement of water in the ocean.

2. Ocean currents assist in maintaining the Earth's heat balance.

3. Ocean currents are set in motion primarily by prevailing winds.

4. Ocean currents are affected by the configuration of the ocean.

Which of these statements are correct?

Correct Answer: (d) 1, 2, 3 and 4
Solution:The flow of ocean water in a particular direction is called the oceanic current. Mostly ocean currents are set in motion by the prevailing wind. If the wind is blow, normally the surface water is in motion.

Thus, statement 1 and 3 are correct. In cold regions hot streams (Gulf stream) and in hot regions cold streams play their role in heat stabilization. Thus statement 2 is also correct. Ocean currents are also affected by the configuration of the ocean besides prevailing winds and Earth's rotation. Thus, statement 4 is also correct.

3. Which one of the following factors is responsible for the change in the regular direction of the ocean currents in the Indian Ocean? [I.A.S. (Pre) 1997]

Correct Answer: (b) Indian Ocean has Monsoon drift
Solution:The ocean currents of the Indian Ocean are slightly different from the Pacific and the Atlantic Ocean. Land and monsoon winds have a major impact on the Indian Oceanic current.

The direction of current flow changes twice in the Northern Indian Ocean due to the North-East and South-West monsoon winds whereas Southern Indian Ocean currents have a definite pattern. Hence, option (b) is the correct answer.

4. Agulhas current flows in – [R.A.S./R.T.S. (Pre) 1999]

Correct Answer: (a) The Indian Ocean
Solution:Agulhas current is the warm water current which flows in South Indian Ocean. The South Equatorial current turns southward and divided into Madagascar current and Mozambique current .

These currents merge south of Madagascar as Agulhas warm current and then it flows up to southernmost end of Africa and later it mixes with Westwind drift by turning to East.

5. Which of the following ocean currents is associated with Indian Ocean? [U.P.P.C.S. (Pre) 2020]

Correct Answer: (c) Agulhas Current
Solution:Agulhas current is the warm water current which flows in South Indian Ocean. The South Equatorial current turns southward and divided into Madagascar current and Mozambique current .

These currents merge south of Madagascar as Agulhas warm current and then it flows up to southernmost end of Africa and later it mixes with Westwind drift by turning to East.

6. Which of the following is not a cold ocean current? [U.P.P.C.S. (Pre) 2017]

Correct Answer: (d) Agulhas
Solution:Agulhas current is the warm water current which flows in South Indian Ocean. The South Equatorial current turns southward and divided into Madagascar current and Mozambique current .

These currents merge south of Madagascar as Agulhas warm current and then it flows up to southernmost end of Africa and later it mixes with Westwind drift by turning to East.

7. The country benefiting the most out of the North Atlantic Drift is : [R.A.S./R.T.S.(Pre) 1999]

Correct Answer: (c) Norway
Solution:Northern Atlantic currents generate near 45° north latitude and 45° west meridian. It takes away the water of warm Gulf stream towards Europe, where Norway, situated in the sub-polar region, is benefited most by this current.

This benefit is in such a way that when at the onset of winter chances of most of the countries of Europe coming under the expansion of ice-covering becomes greater than warm north Atlantic currents block the expansion of ice-cover and therefore this current is also known as 'Blanket of Europe'.

8. Which one of the following is a cold current of the South Atlantic Ocean? [U.P.P.C.S. (Pre) 2005]

Correct Answer: (b) Benguela current
Solution:An only cold current of South Atlantic Ocean is the "Benguela current". It flows along the west coast of Southern Africa towards the North direction. Moving ahead, it merges with South Equatorial current. Therefore option (b) is correct. Other currents of the options are as follows —
  • Brazil Current: It is a warm water current which flows along the East coast of Brazil from north to south.
  • Canary Current: It is a cold water current which flows in the North Atlantic Ocean along the west coast of north-west Africa from north to south direction.
  • Agulhas Current: It is a warm water current which flows in South-Indian Ocean from north to south direction.

9. Which of the following ocean currents does not belong to the Indian Ocean? [U.P.P.C.S. (Mains) 2014]

Correct Answer: (d) Benguela Current
Solution:Agulhas current flows along the west border of the South Indian Ocean and it is a warm current. Mozambique current is also a warm current which flows through Mozambique channel in the West Indian Ocean.

In the 40° to 45° latitudes flows the South Indian Ocean current, while Benguela current is a cold water current which flows in South Atlantic ocean along the west coast of Africa.

10. Which one of the following currents does not contribute to forming a complete circle of currents in the South Atlantic Ocean: [U.P.P.C.S. (Pre) 2000]

Correct Answer: (c) Canary
Solution:In the South Atlantic Ocean, there exists a fixed order of complete circular currents. This order emerges from South Equatorial current. After hitting Brazil coast, it moves towards the south where it is called Brazil current.

The disturbance is developed due to the rotation of the Earth. At 40° latitude, this current is affected by Westwind. It turns to east and current coming from the south i.e., Falklands Current meets with the Brazil current.

Warm Brazil current and cold Falklands current merge and turn to the east-flowing as South Atlantic current and one of its branch after hitting the west coast of South Africa turns towards the north where it is known as Benguela Current.

This current moving ahead and meeting with South Equatorial current forms a complete circle of currents. This complete circle of currents flow in anticlok-wise direction.

Therefore it is clear that Canary current is not associated with the complete circle of South Atlantic currents. This is actually a cold current which flows in the North Atlantic Ocean.