UPSC Prelims 2000 Q14: Geography – Oceanography
Match List I with List II
and select the correct answer using the codes given below the Lists:
List I (Oceanic Trench)
I. Aleutian
II. Kermadec
III. Sunda
IV. S. Sandwich
List II (Location)
A) Indian Ocean
B) North Pacific Ocean
C) South Pacific Ocean
D) South Atlantic Ocean
Codes:
- (a) I - B, II - D, III - A, IV - C
- (b) I - B, II - C, III - A, IV - D
- (c) I - A, II - C, III - B, IV - D
- (d) I - A, II - D, III - B, IV - C
Answer: (b) I - B, II - C, III - A, IV - D
Explanation
Oceanic trenches and their oceans
| Trench | Ocean |
|---|---|
| Aleutian | North Pacific — south of Alaska's Aleutian Islands |
| Kermadec | South Pacific — north-east of New Zealand |
| Sunda (Java) | Indian Ocean — south of Sumatra and Java |
| South Sandwich | South Atlantic — east of the South Sandwich Islands |
Trenches form where one plate sinks beneath another.
The Aleutian Trench lies in the North Pacific, the Kermadec Trench in the South Pacific, the Sunda (Java) Trench in the Indian Ocean, and the South Sandwich Trench in the South Atlantic.
So the match is I-B, II-C, III-A, IV-D.
Answer: (b) I - B, II - C, III - A, IV - D.
Why each option is right or wrong
- (a) Incorrect. Kermadec is in the South Pacific and South Sandwich in the South Atlantic, not the other way round.
- (b) CORRECT. Aleutian-North Pacific, Kermadec-South Pacific, Sunda-Indian, South Sandwich-South Atlantic.
- (c) Incorrect. Aleutian is in the North Pacific, not the Indian Ocean.
- (d) Incorrect. Aleutian and Sunda are both placed wrongly.
Key point
Deepest point on Earth: Challenger Deep in the Mariana Trench (about 10,900 m), western Pacific.
Remember
Aleutian N. Pacific, Kermadec S. Pacific, Sunda Indian, S. Sandwich S. Atlantic.
Common mistakes
- Placing the Sunda Trench in the Pacific because Indonesia borders both oceans.
- Putting Kermadec in the Atlantic.
- Forgetting that the South Sandwich Trench is the deepest in the Atlantic's south.
Exam tip
Most trenches ring the Pacific; Sunda is the Indian Ocean's, South Sandwich the South Atlantic's.
Sources
- G. C. Leong — Certificate Physical and Human Geography, chapter 'The Oceans' (ocean deeps)
- NCERT Class XI — Fundamentals of Physical Geography, chapter 'Water (Oceans)' (relief of the ocean floor)