Geography · Environmental Studies

Oceanography and Hydrology

1,673 Questions

Find relevant questions on oceanography and hydrology that address aquatic ecosystems and physical geography. The topics include coastal landforms, coral reefs, ocean salinity, and tidal patterns. These concepts frequently appear in civil services and state level administrative examinations.

Coral reef structuresCoastal landformsOcean salinity patternsGlacial retreat impactsMangrove ecosystems

Oceanography and Hydrology Questions

Multiple choice

Consider the following statements: Salinity of water in the equatorial ocean decreases because

  1. large rivers like Amazon and Congo enter into the sea
  2. evaporation is less.
  3. waters from Arctic and Antarctic mix with waters of equator.
  4. of heavy rainfall.

Which of these statements are correct?

  1. 1 and 2

  2. 3 and 4

  3. 1 and 3

  4. 1 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Equatorial ocean salinity decreases primarily because: (1) large rivers like Amazon and Congo discharge tremendous freshwater volume, and (4) heavy rainfall directly dilutes surface waters. Statement 2 about evaporation is incorrect - evaporation is actually high in equatorial regions, which would increase salinity. Statement 3 about polar waters mixing is incorrect.

Multiple choice

Spring tide means

  1. Higher high tide, higher low tide

  2. Higher high tide, lower low tide

  3. Lower high tide, lower low tide

  4. Lower low tide, higher low tide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Spring tides occur when the Sun, Moon, and Earth align during new moon or full moon phases, creating the greatest tidal range. This alignment produces both higher high tides and higher low tides than normal, as gravitational forces combine to maximize water movement.

Multiple choice

Consider the following statements

  1. Continental shelves are wider where high mountains area very close and parallel to the coast.
  2. Continental shelves are formed by prolonged deposition of detritus under sea water in those areas where sea conditions are calm.
  3. Extensive continental margins during the time of negative change of the sea level.
  4. Continental shelves are formed by the submergence of continental margins due to tilting of land towards sea.

Which of the above statements are correct?

  1. 1, 2 and 3

  2. 2, 3 and 4

  3. 1, 3 and 4

  4. 1, 2 and 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statements 2, 3, and 4 are correct: shelves form by prolonged deposition under calm conditions (2), can expand during negative sea level changes (3), and form through submergence due to land tilting (4). Statement 1 is incorrect because shelves are typically narrower where high mountains parallel the coast, not wider. Thus option B (2, 3, 4) is correct.

Multiple choice

Salinity in ocean water is decrease when

  1. evaporation is more

  2. wind velocity is high

  3. rainfall is heavy

  4. humidity is high
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ocean salinity decreases when freshwater input increases. Heavy rainfall (C) adds fresh water to oceans, diluting salt content. High evaporation increases salinity by removing water while leaving salts behind. Wind velocity and humidity affect evaporation rates but don't directly decrease salinity like rainfall does.

Multiple choice

Which one of the following statements is not correct?

  1. Gulf with narrow fronts and wider rears experiences high tides.

  2. Tidal currents take place when a gulf is connected with the open sea by a narrow channel.

  3. Tidal bore occurs when a tide enters the row and shallow estuary of a river.

  4. The tidal nature of the mouth of the river Hooghly is of crucial importance to Kolkata as a port.
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice

Top layer of marine ecosystem possess

  1. planktons

  2. nektons

  3. both of the above

  4. neustons

  5. benthos
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The collection of minute or microscopic organisms that inhabit the surface layer of a body of water

Multiple choice

Wetlands are a source of

Directions: Read the passage and answer the question that follows:

Wetlands are indeed the vital link between water and land. It is the collective term for marshes, swamps, and bogs, found along the edges of streams, rivers, lakes and coastlines. Wetlands can be found in nearly every country and climatic zone. Indeed wetlands are found from the Tundra to the Tropics and on every continent. They are so varied. Some are wet all the time. Some wetlands are large and some are very small. Many have been altered by human activities such as farming, building of roads, dams and towns. Wetlands are regarded wastelands sources of mosquitoes, flies, snakes and diseases. People had negative views about them and they eliminated them. Original wetlands have been destroyed; some of them have been converted into farmland, some others filled by industrial wastes.
Wetlands vary widely because of topography, climate, hydrology, water chemistry and vegetation. Wetlands are the coastal mangrove forests, lake marshes and seasonally flooded lands along river courses. Palm swamps, sea grass beds, salt flats, and coral reefs are common wetlands. They are of two types: tidal wetlands and non-tidal (inland) wetlands. Tidal wetlands are found along the Atlantic, Pacific, Alaskan and Gulf Coasts. The salt water and fluctuating water levels create a difficult environment. Some plants have adapted to the environment of saline conditions. Inland wetlands are common in the margins of lakes and rivers. They include wet meadows dominated by herbaceous plants, swamps and shrubs and tall trees. The prolonged presence of water favours the growth of specially adapted plants.
States and tribes play a critical role in the protection and management of wetlands. With the growth of education, people have started understanding ecological processes and their attitude towards wetlands have changed. They have recognised the ecological significance of the wetlands; they are a source of valuable natural wealth. They help regulating water levels within watersheds; reduce flood and storm damages; and provide fish and wildlife habitat. They support hunting, fishing and other recreational activities.

Wetlands are the most productive ecosystems in the world. They have been described as biological supermarkets as they provide great volumes of food and attract many animal species. A variety of insects, amphibians, reptiles, birds, fish and mammals are found in these wetlands. Many species of birds, animals, rely on wetlands for food, water and shelter. The microbes, insects and wildlife are part of global cycles for water, nitrogen, and sulphur. They store carbon within their plant communities and thus help to moderate climate conditions.

  1. natural wealth

  2. natural protection

  3. productive ecosystems

  4. All of the above

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Options (1), (2) and (3) have been directly mentioned in the last two paragraphs. Hence, option (4) is the correct answer.

Multiple choice

The term strait in geography refers to

  1. Large accumulation of snow

  2. A narrow passage of water connecting two large areas of water and separating two land masses

  3. A narrow track of land separating two large bodies of water and connecting two land masses

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A strait is a naturally formed, narrow, typically navigable waterway that connects two larger bodies of water and separates two land masses. Option B accurately defines this geographical feature. Option C describes an isthmus (land connecting two land masses), not a strait.

Multiple choice

Currents in the oceans are a result of

  1. Salinity deference from place to place

  2. Temperature differences

  3. The Gulf stream motion

  4. The Labrador current movement
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ocean currents are primarily driven by temperature differences between equatorial and polar regions. Warm water from the equator moves toward poles, while cold water from polar regions flows toward the equator. These temperature differences create density variations that drive thermohaline circulation, the global ocean conveyor belt.