27
practice examMultiple Choice

Practice Exam

Question 27 • Earth and Space Science

Assume that unusually strong winds mixed the water column in summer. What would most likely happen to oxygen levels at the bottom?

Answer
A
Oxygen would decrease further because mixing reduces circulation.
B
Oxygen would disappear completely due to stratification.
C
Oxygen would remain unchanged since mixing does not affect gases.
D
Oxygen would increase because surface oxygen would be mixed downward.

Explanation

Strong winds would mix surface water down toward the bottom. Because surface water contains oxygen, this mixing would carry oxygen into deeper water and raise bottom oxygen levels. Therefore, the most likely result is that oxygen would increase because surface oxygen would be mixed downward.

AI-written and checked against the verified answer.

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