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

Which of the following statements is/are correct? a. The temperature-depth profile for the ocean water shows that the temperature decreases with the increasing depth. b. The boundary region, from where there is a rapid decrease of temperature, is called the thermocline. c. In the arctic and antarctic circles only one layer of cold water exists, which extends from the surface to deep ocean floor.

  1. a only

  2. b only

  3. c only

  4. a and c

  5. a, b and c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer as all the statements are correct. The temperature-depth profile for the ocean water shows that the temperature decreases with the increasing depth. The boundary region, from where there is a rapid decrease of temperature, is called the thermocline. In the arctic and antarctic circles only one layer of cold water exists, which extends from the surface to deep ocean floor.

Multiple choice

Which of the following is correct about the halocline?

  1. The salinity increases sharply at the halocline.

  2. The temperature decreases sharply at the halocline.

  3. The currents shift sharply at the halocline.

  4. The salinity at the surface of the ocean is called halocline.

  5. The zone where salinity is fixed in the ocean is called the halocline.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct answer. Salinity generally increases with depth and there is a distinct zone called the halocline, where salinity increases sharply.

Multiple choice

Match the Components and the Processes of the water cycle ||| |---|---| | Components| Processes| |a. Water storage in oceans|1. Fresh water storage infiltration | |b. Water in atmosphere|2. Evapotranspiration | |c. Surface runoff|3. Precipitation|

  1. a-1, b-2, c-3

  2. a-2, b-3, c-1

  3. a-3, b-1, c-2

  4. a-2, b-1, c-3

  5. a-3, b-2, c-1
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct matching. The processes that the ocean undergoes are evaporation and evapotranspiration. The processes that the water in the atmosphere undergoes are condensation and precipitation. The processes that the water from the surface run-off undergoes are stream flow and freshwater storage infiltration.

Multiple choice

Which of the following statements is/are correct?

a. Deep sea plains are gently sloping areas of the ocean basins. b. These plains are covered with fine-grained sediments like clay and silt. c. The deep sea plains are very significant in the study of tectonic plate movements.

  1. a only

  2. b only

  3. c only

  4. a and b

  5. a, b and c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Deep sea plains are gently sloping areas of the ocean basins. These plains are covered with fine-grained sediments like clay and silt. Both these statements are correct.

Multiple choice

Which of the following statements is/are incorrect? a. The continental shelf is the shallowest part of the ocean. b. The continental shelves are a source of fossil fuels. c. The continental shelf typically ends at a very steep slope, called the shelf slope.

  1. only a

  2. only b

  3. only c

  4. a and c

  5. b and c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The shelf typically ends at a very steep slope, called the shelf break. A continental shelf is a major relief feature. This statement is incorrect.

Multiple choice

What percent of total water present on earth is in continuous circulation?

  1. One percent

  2. Three percent

  3. Two percent

  4. Four percent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Approximately one percent of Earth's total water is actively participating in the hydrologic cycle at any given time. The vast majority (over 97%) is saline ocean water, while most freshwater is locked in glaciers, ice caps, and groundwater. Only a small fraction circulates through evaporation, precipitation, and runoff, sustaining all terrestrial and freshwater life. This cycling portion is essential for ecosystem function and human use.

Multiple choice

Rossby waves are related to __________.

  1. weather

  2. seismic belt

  3. ocean

  4. pond

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rossby waves are large-scale atmospheric waves associated with the meandering of the jet stream in the upper atmosphere. These planetary waves play a crucial role in weather patterns by influencing the movement of air masses and the formation of high and low-pressure systems. They are not related to seismic activity, ocean currents, or small water bodies.

Multiple choice

Tides in the oceans and seas are caused by ______.

  1. daily motion of the earth

  2. annual motion of the earth

  3. gravitational attraction of the moon

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ocean tides are primarily caused by the gravitational pull of the moon on Earth's oceans. The moon's gravity creates a bulge in ocean water on the side facing it. The sun also contributes but has less effect due to greater distance. Earth's daily motion affects tides but doesn't cause them.

Multiple choice

Which of the following is a mismatched pair?

  1. Neritic zone - shallow area over continental shelf

  2. Abyssal zone - deepest benthic zone

  3. Intertidal zone - characterised by presence of plants

  4. Pelagic zone - area of open water

  5. Littoral zonre - close to the shore
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the intertidal zone, the most common organisms are small and most are relatively uncomplicated organisms.

Multiple choice

Fishing groups are concentrated in the high latitudes the reasons are

  1. great length of indented coastline
  2. extensive continental coastline
  3. water temperature lower than 20o C
  4. sparse population

  1. 2, 3 and 4

  2. 1 and 2

  3. 2 and 4

  4. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

High-latitude fishing grounds (like the North Atlantic) have extensive continental shelves (reason 2), indented coastlines (reason 1), and cold water below 20°C (reason 3). Sparse population is irrelevant - fishing depends on ocean conditions, not human settlement patterns.

Multiple choice

Red tide is caused by

  1. protozoans

  2. corals

  3. dinoflagellates

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Red tide is caused by dinoflagellates (like Karenia brevis), which are microscopic algae that can reproduce rapidly and produce harmful toxins that color the water red. They are neither protozoans, corals, nor all of the above.

Multiple choice

Mean sea level means

  1. the average depth of the sea-level in the pacific ocean

  2. the mean of the sea level in the pacific ocean

  3. the average level of the sea

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mean sea level is the average surface level of the ocean, calculated from tidal observations over a long period. It serves as the reference point (zero elevation) for measuring altitude and depth on Earth. Options A and B incorrectly specify the Pacific Ocean, which would be a regional measure, not the global standard.

Multiple choice

Which of the following statements is incorrect?

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

  2. Coastal water pollution can cause red tides.

  3. The occurrence of red tides may be natural or from human activities.

  4. When the algae are present in high concentrations, the water appears to be discolored.

  5. Red tides are related to the movements of the tides.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

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