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OG.1/06.4(b)
M.Sc. DEGREE I SEMESTER EXAMINATION IN OCEANOGRAPHY, DECEMBER 2006
OCE 2101 INTRODUCTION TO OCEANS
Maximum marks: 50
Time: 3 Hours
SECTION - A
(Answer ALL questions)
(All questions carry EQUAL marks)
(10 x I = 10)
I.
Choose the most appropriate alternative:
1.
The deepest point in the Indian ocean is in
(a)
Mariana trench
(b)
Phillippines trench
(c)
Java trend
(d)
Puerto Rico trough
2.
Bathythermograph is used to measure
(a)
Density
(b)
Temperature
(c)
Variation of density with depth
(d)
Variation of temperature with depth
3.
Annual variation of sea surface temperature is maximum at
(a)
The equator
(b)
30° latitude
(c)
60° latitude
(d)
The pole
4.
Bowen's ratio is
(a)
R=-
Qe
Qb
(b)
R=-
(c)
R=-
Qb
Qe
Qe
Qh
(d)
R=-
Qh
Qe
where Qb, Qh and Qe are that heat losses due to back radiation, convection and
evaporation respectively.
5.
In coastal waters light transparency is greatest at the wave length of
(a)
70 micron
(b)
53 micron
(c)
48 micron
(d)
40 micron
fT",,"
nil"")
.......
v
2
6.
In a tropical ocean the vertical sound velocity distribution below the thermocline is such that
the sound velocity
(a)
Decreases
(b)
Increases
(c)
Decreases fIrst and then increases
(d)
Increases fIrst and then decreases
as the depth increases
7.
The low salinity water observed just below the central water mass in southern hemisphere
indicates the presence of
(a)
Antarctic intermediate water mass
(b)
Arctic intermediate water mass
(c)
Atlantic deep water mass
(d)
Atlantic bottom water mass
8.
Humboldt current is in
(a)
Atlantic ocean
(b)
PacifIc ocean
(c)
Indian ocean
(d)
Antarctic ocean
9.
Upwelling along Kerala coast is obs'ervedduring
(a)
January to March
(b)
April to June
(c)
July to September
(d)
October to December
10.
The phase speed of a deep water wave is
gT
(a)
c=-
(b)
c=- gT2
271
271
(c)
c=- gL
(d)
c=- gi
271
2Jr
where T and L are the period and the length of the wave respectively.
SECTION - B
(Answer ANY SIX questions in about 300 words each)
(All questions carry EQUAL marks)
(6 x 4= 24)
II.
Write a note on the measurement of evaporation at the sea.
evaporation with latitude.
III
Differentiate between the ideal sea level, physical sea level and mean sea level. Discuss the
periodic, non-periodic and eustatic changes that cause the seal level to deviate from its ideal state.
How is the mean sea level determined.
Discuss the variation of annual
rrnnttl_u
?)
IV
Write a note on the colour of the sea. How is it estimated?
V.
Write a note on T-S diagram and its uses. Differentiate between water mass and water type.
VI.
Write an account on the equatorial current system in the Indian ocean bringing out its seasona
changes.
VII.
Differentiate the characteristics of waves in the generating area and the decay area. Discuss tht
reasons for the decrease of wave height as the waves propagate through the decay area.
VIII.
Write a note on storm surges. Explain why they are classified as a long wave.
IX.
What are tide generating forces. Explain how they give rise to the semi-diurnal nature of the tide.
SECTION - C
(Answer ALL questions in about 1200 words each)
(All questions carry EQUAL marks)
(2 x 8 = 16
X.
A.
B.
XI.
A.
B.
Write a detailed account on the determination of temperature, salinity, sigma-t and specifi
volume anomaly in the sea.
OR
Describe the meredonialand vertical variationsof temperature,salinity and density in th
worldoceans. Discussthe annualvariationsof theseparameterswithlatitude.
Write a note on the formation and classification of water masses. Describe the water masse
in the Indian ocean with special reference to northern Indian ocean.
OR
Describe how Ekman.transport causes upwelling and sinking in the oceans. Give an accom
on the important upwelling regions of the world oceans with special reference to India
ocean.