Microtheme: Oceanography —
11 questions asked in Prelims in the past.

1. [2024] Which of the following is/are correct inference/inferences from isothermal maps in the month of January?
   1. The isotherms deviate to the north over the ocean and to the south over the continent.
   2. The presence of cold ocean currents, Gulf Stream and North Atlantic Drift make the North Atlantic Ocean colder and the isotherms bend towards the north.
   Select the answer using the code given below:
   • (a) 1 only
   • (b) 2 only
   • (c) Both 1 and 2
   • (d) Neither 1 nor 2
   Correct Answer: (A) 1 only
2. [2021] Consider the following statements:
   1.In the tropical zone, the western sections of the oceans are warmer than the eastern sections owing to the influence of trade winds.
   2.In the temperate zone, westerlies make the eastern sections of oceans warmer than the western sections.
   Which of the statements given above is/are correct?
   • (a) 1 only
   • (b) 2 only
   • (c) Both 1 and 2
   • (d) Neither 1 nor 2
   Correct Answer: (C) Both 1 and 2
3. [2020] With reference to Ocean Mean Temperature (OMT), which of the following statements
   is/are correct?
   1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the southwestern Indian Ocean during January – March.
   2. OMT collected during January – March can be used in assessing whether the
   amount of rainfall in monsoon will be less or more than a certain long-term mean.
   Select the correct answer using the code given below:
   • (a) 1 only
   • (b) 2 only
   • (c) Both 1 and 2
   • (d) Neither 1 nor 2
   Correct Answer: (B) 2 only
4. [2017] At one of the places in India, if you stand on the seashore and watch the sea, you will find that the sea water recedes from the shore line a few kilometers and comes back to the shore, twice a day, and you can actually walk on the sea floor when the water recedes. This unique phenomenon is seen at
   • (a) Bhavnagar
   • (b) Bheemunipatnam
   • (c) Chandipur
   • (d) Nagapattinam
   Correct Answer: (C) Chandipur
5. [2015] Tides occur in the oceans and seas due to which among the following?
   (1) Gravitational force of the Sun
   (2) Gravitational force of the Moon
   (3) Centrifugal force of the Earth
   Select the correct answer using the code given below.
   • (a) 1 only
   • (b) 2 and 3 only
   • (c) 1 and 3 only
   • (d) 1, 2 and 3
   Correct Answer: (D) 1, 2 and 3
6. [2015] In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not
   originate What is the reason?
   • (a) Sea surface temperatures are low
   • (b) Inter-Tropical convergence Zone seldom occurs
   • (c) Coriolis force is too weak
   • (d) Absence of land in those regions
   Correct Answer: (B) Inter-Tropical convergence Zone seldom occurs
7. [2015] What explains the eastward flow of the equatorial counter-current?
   • (a) The Earth's rotation on its own axis
   • (b) Convergence of the two equatorial currents
   • (c) Difference is salinity of water
   • (d) Occurance of the belt of calm near the equator What explains the eastward flow of the equatorial counter-current?
   Correct Answer: (B) Convergence of the two equatorial currents
8. [2013] The most important fishing grounds of the world are found in the regions where
   • (a) warm and cold atmospheric currents meet
   • (b) rivers drain out large amounts of freshwater into the sea
   • (c) warm and cold oceanic currents meet
   • (d) continental shelf is undulating
   Correct Answer: (C) warm and cold oceanic currents meet
9. [2012] Consider the following factors
   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 influence the ocean currents?
   • (a) 1 and 2 Only
   • (b) 1, 2 and 3
   • (c) 1 and 4
   • (d) 2, 3 and 4
   Correct Answer: (B) 1, 2 and 3
10. [2010] A new type of El Nino called El Nino Modoki appeared in the news. In this context, consider the following statements:
    1. Normal El Nino forms in the Central Pacific ocean whereas El-Nino Modoki forms in Eastern Pacific ocean.
    2. Normal EI Nino results in diminished hurricanes in the Atlantic ocean but El Nino Modoki results in a greater number of hurricanes with greater frequency.
    Which of the statements given above is/are correct ?
    • (a) 1 only
    • (b) 2 only
    • (c) Both 1 and 2
    • (d) Neither 1 nor 2
    Correct Answer: (B) 2 only
11. [2009] Consider the following names :
    1. Ike
    2. Kate
    3. Gustav
    Which of the above are the names of hurricanes that had occurred very recently ?
    • (a) 1 and 2 only
    • (b) 2 and 3 only
    • (c) 1 and 3 only
    • (d) 1,2 and 3
    Correct Answer: (C) 1 and 3 only