Geography · Environmental Studies

Oceanography and Hydrology

1,743 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

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.

Multiple choice

Lagoons are often found

  1. between the high walk and low water line

  2. between the coast and the offshore bar

  3. on the seaward side of the fringing reef

  4. on the seaward side of the offshore bar
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice

The cold oceanic current passing through the coast of North American is known as

  1. Kuroshio Current

  2. Gulf Stream

  3. Labrador Current

  4. Falkland Current
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Labrador Current is a cold ocean current that flows south from the Arctic Ocean along the coast of Labrador and Newfoundland in eastern Canada. It meets the warm Gulf Stream near the Grand Banks, creating fog and affecting regional climate.

Multiple choice

The circulation of ocean water occurs

  1. only laterally

  2. only vertically

  3. both laterally and vertically

  4. neither laterally nor vertically
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ocean water moves both horizontally through surface currents driven by wind and density differences, and vertically through upwelling and downwelling processes. This complex circulation system includes thermohaline circulation that moves water between surface and deep ocean layers.

Multiple choice

Consider the following facts:

  1. Ocean acidification is the name given to the ongoing process of increase in the pH level of oceans.
  2. It is caused by the increased anthropogenic emission of carbon dioxide which gets dissolved in water.

Which of the above is/are true?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ocean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide (CO2) from the atmosphere. About 30–40% of the carbon dioxide released by humans into the atmosphere dissolves into the oceans, rivers and lakes.

Multiple choice

Tides in the oceans are caused by

  1. gravitational pull of the moon on the earth's surface including sea water

  2. gravitational pull of the sun on the earth's surface only and not on the sea water

  3. gravitational pull of the sun on the earth's surface including the sea water

  4. gravitational pull of the sun and the moon on the earth's surface including the sea water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tides are caused by the gravitational pull of BOTH the sun and moon on Earth's surface, including the oceans. While the moon's influence is stronger (about twice as much as the sun's) due to its proximity, both celestial bodies contribute to tidal forces. The gravitational pull creates tidal bulges on both sides of Earth, leading to high and low tides. The sun's gravitational pull definitely affects seawater, not just land.

Multiple choice

Red Tide is a common name for a phenomenon known as an algal bloom, an event in which estuarine, marine or fresh water algae accumulate rapidly. Which among the following statements does not characterise red tides?

  1. When the algae are present in high concentrations, the water appears to be discoloured.

  2. Red tides are related to the movements of tides.

  3. Iron-rich dust influx from a large desert can cause red tides.

  4. Coastal water pollution can cause red tides.

  5. The occurrence of red tides may be natural or from human activities.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Red tides are unrelated to movements of the tides.They are not necessarily red and many have no discoloration at all.They are

Multiple choice

In Which of the following options depth of the sea is measured?

  1. Fathoms

  2. Miles

  3. Metres

  4. Nautical miles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fathoms are a traditional nautical unit specifically used for measuring water depth. One fathom equals 6 feet. Miles, meters, and nautical miles measure distance but are not the specific term for sea depth measurement.

Multiple choice

The important fishing areas called Grand Banks and Georges Bank are located in the waters of which one of the following?

  1. North Pacific

  2. South Pacific

  3. South - west Atlantic

  4. North - west Atlantic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Grand Banks and Georges Bank are famous fishing grounds located off the coast of Newfoundland and New England respectively, in the North-west Atlantic Ocean. These are among the richest fishing grounds in the world due to the mixing of cold and warm currents creating ideal conditions for marine life.

Multiple choice

Select which water body is the source of marine water?

  1. Well

  2. Pond

  3. Lake

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

Water is present as marine water or fresh water. Marine water is that which consists of large amounts of salts and minerals thus known as saline water. Freshwater does not consist of salts. Rivers, ponds and lakes are freshwater sources and ocean is a source of marine water.