Oceanography Questions and Answers

Q: List of Sea water layers (List-I) and the density (List-II) are given below. Match the List-I and List-II and select the correct answer from the codes given below :List IList II(a) Photic layer(i) Sharp density gradient(b) Pycnocline layer(ii) Highest density(c) Deep/bottom layer(iii) Lowest density.

The correct matching is a-(iii), b-(i), c-(ii).The photic layer at the surface is the warmest and is diluted by rain and rivers, so it has the lowest density. Below it, the pycnocline is the zone in which density increases sharply with depth, mainly because temperature falls quickly (the thermocline). The deep or bottom layer is cold and dense, so it has the highest density.The other codes give the surface layer the sharp gradient or the highest density, or put the lowest density at the bottom, which would make the water column unstable.

Q: A Line or Surface drawn on a map or chart to indicate connecting points of equal salinity in the Ocean is known as

The line is an isohaline.An isohaline joins points of equal salinity in the ocean (from Greek halos, salt). Oceanographers use isohalines to map how salinity varies with latitude and depth.An isobar joins points of equal atmospheric pressure, and an isotherm joins points of equal temperature. Isoline is the general name for any line of equal value, so it is the family name, not the specific term for salinity.

Q: The highest tides occur at the time of the new moon and the

The highest tides occur at the new moon and the full moon.At new moon and full moon the sun, the earth and the moon lie in a straight line. The tide-raising pulls of the sun and the moon then act together, producing the highest high tides and lowest low tides, called spring tides. When the sun and moon are at right angles to the earth, at the first and last quarters, the pulls partly cancel and give the weaker neap tides.Eclipses happen only at new or full moon, but most new and full moons pass without one, so an eclipse is not what produces spring tides. Volcanoes have no effect on the tides.

101.

List of Sea water layers (List-I) and the density (List-II) are given below. Match the List-I and List-II and select the correct answer from the codes given below :

List I	List II
(a) Photic layer	(i) Sharp density gradient
(b) Pycnocline layer	(ii) Highest density
(c) Deep/bottom layer	(iii) Lowest density.

A.a-(i), b-(iii), c-(ii)
B.a-(ii), b-(i), c-(iii)
C.a-(iii), b-(i), c-(ii)
D.a-(i), b-(ii), c-(iii)

Exam Year(s)

MH SET - 2025, SET Exam - 2025,

Answer: C

The correct matching is a-(iii), b-(i), c-(ii).

The photic layer at the surface is the warmest and is diluted by rain and rivers, so it has the lowest density. Below it, the pycnocline is the zone in which density increases sharply with depth, mainly because temperature falls quickly (the thermocline). The deep or bottom layer is cold and dense, so it has the highest density.

The other codes give the surface layer the sharp gradient or the highest density, or put the lowest density at the bottom, which would make the water column unstable.

Discuss in Forum

102.

A Line or Surface drawn on a map or chart to indicate connecting points of equal salinity in the Ocean is known as

A.Isobar
B.Isotherm
C.Isoline
D.Isohaline

Exam Year(s)

Tripura Public Service Commission - 2026,

Answer: D

The line is an isohaline.

An isohaline joins points of equal salinity in the ocean (from Greek halos, salt). Oceanographers use isohalines to map how salinity varies with latitude and depth.

An isobar joins points of equal atmospheric pressure, and an isotherm joins points of equal temperature. Isoline is the general name for any line of equal value, so it is the family name, not the specific term for salinity.

Discuss in Forum

103.

The highest tides occur at the time of the new moon and the

A.full moon
B.solar eclipse
C.lunar eclipse
D.volcanoes

Exam Year(s)

Tripura Public Service Commission - 2015,

Answer: A

The highest tides occur at the new moon and the full moon.

At new moon and full moon the sun, the earth and the moon lie in a straight line. The tide-raising pulls of the sun and the moon then act together, producing the highest high tides and lowest low tides, called spring tides. When the sun and moon are at right angles to the earth, at the first and last quarters, the pulls partly cancel and give the weaker neap tides.

Eclipses happen only at new or full moon, but most new and full moons pass without one, so an eclipse is not what produces spring tides. Volcanoes have no effect on the tides.

Discuss in Forum

104.

One of the proponents of the turbidity current theory of the origin of submarine canyons was

A.Daly
B.Dana
C.Salis
D.Gregory

Exam Year(s)

UGC NET - 2012,

Answer: A

R.A. Daly proposed in 1936 that submarine canyons were cut by turbidity currents, which are dense, sediment-laden flows moving down the continental slope. During the glacial low sea level the muddy water from rivers was thought to run down and scour the canyons.

Dana is associated with the geosynclinal theory and with coral reefs, and Gregory is known for his work on the Great Rift Valley. They are not the proponents of the turbidity current theory of canyons, so Daly is the key.

Discuss in Forum

105.

The most common salt in the ocean is

A.Calcium chloride
B.Sodium nitrate
C.Sodium chloride
D.Calcium nitrate

Exam Year(s)

UGC NET - 2012,

Answer: C

The most common salt in sea water is sodium chloride, about 78 percent of all dissolved salts at an average salinity of 35 parts per thousand. Calcium chloride makes up only a small amount, and the nitrates are tiny traces.

Options A, B and D are not abundant in the ocean: other significant salts are magnesium chloride, magnesium sulphate and calcium sulphate, but none of them approaches the share of sodium chloride.

Discuss in Forum

106.

Pelagic deposits consist of matter derived from algae and are mostly in the form of liquid mud known as

A.Blue mud
B.Ooze
C.Red mud
D.Coral mud

Exam Year(s)

UGC NET - 2012,

Answer: B

Pelagic deposits that consist of the remains of algae and other organisms and are mostly in the form of liquid mud are known as ooze. Calcareous and siliceous oozes cover large areas of the deep ocean floor.

Blue mud, red mud and coral mud are terrigenous or shallow water deposits, near continental margins or reefs, and are not formed mainly of the organic remains of surface organisms, so they are wrong.

Ooze is divided into calcareous ooze, made from the shells of foraminifera and other organisms, and siliceous ooze, made of diatoms and radiolaria. It is called pelagic because it is formed in the open ocean far from the land, and it settles very slowly.

Discuss in Forum

107.

The average temperature of the surface water of the oceans is

A.22 °C
B.15 °C
C.26.7 °C
D.18.6 °C

Exam Year(s)

UGC NET - 2012,

Answer: D

The key gives 18.6 °C as the average temperature of the surface water of the oceans (option D). The figure is a mean of surface water over all latitudes, which is far lower than the 26.7 °C of the equatorial belt because the polar waters are very cold.

22 °C, 15 °C and 26.7 °C are not the figure accepted by the key. 26.7 °C is a tropical value, and 15 °C is nearer the average temperature of the earth's surface air.

Discuss in Forum

108.

Which one of the following ocean currents belongs to Indian Ocean ?

A.Canary Current
B.Antilles Current
C.Labrador Current
D.Agulhas Current

Exam Year(s)

UGC NET - 2012,

Answer: D

The Agulhas Current belongs to the Indian Ocean; it flows south-west along the east coast of Africa.

The Canary Current is in the North Atlantic off north-west Africa. The Antilles Current is in the western North Atlantic and the Labrador Current is a cold current of the North Atlantic. None of those three is in the Indian Ocean.

The Agulhas Current is a warm current that flows along the south east coast of Africa. The other three are of the Atlantic Ocean: the Canary Current is a cold current off north west Africa and the Labrador Current is a cold current off Canada, while the Antilles Current is a warm current of the West Indies.

Discuss in Forum

109.

The Western Coast of Australia records higher salinity due to

A.Ocean currents
B.Wind direction
C.Dry weather condition
D.All the above

Exam Year(s)

UGC NET - 2012,

Answer: C

The key gives dry weather condition as the reason for the higher salinity along the Western Coast of Australia. The region has high temperature, little rainfall and little river water, so evaporation exceeds the freshwater supply and salts are concentrated.

Ocean currents and wind direction affect the distribution of salinity, but the key takes the dry climate as the cause. Option D, 'All the above', is therefore not accepted.

Dry weather means low rainfall and little cloud, so the surface water loses a great deal by evaporation, and the salts left behind raise the salinity. The key treats this as the cause, and other factors are less important there than the dry conditions.

Discuss in Forum

110.

The highest salinity is found in the

A.Baltic Sea
B.Okhotsk Sea
C.Mediterranean Sea
D.Red Sea

Exam Year(s)

UGC NET - 2012,

Answer: D

The Red Sea has the highest salinity of the seas listed. It lies in a hot arid region with very high evaporation, no large river flowing in and little rainfall, and it has restricted connection with the open ocean.

The Baltic Sea and the Okhotsk Sea are cold seas that receive much river water and have low evaporation, so their salinity is low. The Mediterranean Sea is quite saline but less so than the Red Sea.

In the Red Sea the salinity is more than 40 parts per thousand, as the sea has a hot dry climate, receives hardly any river inflow and has only a narrow connection with the Indian Ocean. The Baltic Sea is among the least saline seas of the world.

Oceanography Questions and Answers

Topics

Other Subjects

Tags: Oceanography Questions and Answers

About Us

Oceanography Questions and Answers

Topics

Other Subjects

Tags: Oceanography Questions and Answers

About Us

Stay informed about all important Dates & Notifications