Oceanography: UPSC Previous Year Questions (Geography)
2 previous year UPSC Prelims questions on Oceanography (Geography). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–2 of 2 questions
UPSC 2012Geography · Oceanography
Q1. 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?
Explanation
The Earth’s rotation affects ocean currents through the Coriolis effect, which causes moving fluids like air and water to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection influences the direction of ocean currents.
Option 2 is correct: Wind patterns which are driven by differences in air pressure, are primary drivers of surface ocean currents. The friction between the wind and the ocean surface pushes water, creating currents.
Option 3 is correct: Differences in water density, which are caused by variations in salinity and temperature, influence vertical ocean currents. Cold water is denser and tends to sink, while warm water is lighter and tends to rise. This process contributes to the thermohaline circulation.
Option 4 is incorrect: The revolution of the Earth does not directly influence ocean currents. While the revolution of Earth impacts seasons and sunlight distribution, it is not a direct cause of ocean current movement.
UPSC 2012Geography · Oceanography
Q2. The acidification of oceans is increasing. Why is this phenomenon a cause of concern: 1. The growth and survival of calcareous phytoplankton will be adversely affected. 2. The growth and survival of coral reefs will be adversely affected. 3.The survival of some animals that have phytoplanktonic larvae will be adversely affected. 4. The cloud seeding and formation of clouds will be adversely affected. Which of the statements given above is/are correct?
Explanation
Statement 1 is correct: Ocean acidification reduces the ability of calcareous phytoplankton (such as coccolithophores) to form their calcium carbonate shells. As the ocean becomes more acidic, the process of calcification is impaired, adversely affecting their growth and survival.
Statement 2 is correct: Coral reefs rely on the ability of coral polyps to produce calcium carbonate skeletons. As ocean acidity increases, it becomes more difficult for corals to build and maintain their skeletons, making them more vulnerable. This not only threatens corals themselves but also the ecosystems that depend on them.
Statement 3 is correct: The larvae of some marine organisms, particularly those with phytoplanktonic larvae, rely on calcium carbonate for protection and growth. As the ocean becomes more acidic, these organisms may face difficulties in developing their shells, which could disrupt marine food webs.
Statement 4 is incorrect: While phytoplankton contribute to the release of dimethyl sulfide (DMS), which is linked to cloud formation, ocean acidification does not have a direct and large-scale impact on cloud formation. The reduction in phytoplankton due to ocean acidification may lead to lower DMS emissions, but this effect is relatively minor and unlikely to significantly affect cloud seeding and formation.
Exam tip:
For S1, "calcareous" sounds like calcium. We’re told acidification is happening. Think: Acid + calcium = reaction dissolution or damage. Likely true. For S3, The Phrase "Some animals" make it way too possible and unlikely to be false. Hence true. For S4, Acidification = a chemical change in ocean water. Cloud formation is an atmospheric phenomenon involving moisture, temperature, and dust/aerosols -- not seawater chemistry. There’s no obvious connection here. Hence likely false.
Answer key for these questions
Q
UPSC year
Correct answer
1
2012
(b) 1, 2 and 3
2
2012
(a) 1, 2 and 3 only
Frequently asked questions
How many previous year UPSC questions are there on Oceanography?
This page covers 2 previous year UPSC Prelims GS Paper-I questions on Oceanography (Geography), asked from 1996 to 2024. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Oceanography?
Questions on Oceanography (Geography) are available for 15 years, from 1996 to 2024. Use the Year filter to practise a single paper.
