Which of the Following Statements Regarding Turnover is True

Question

Which of the following statements regarding turnover is true?
A) In fall turnover, dense water at 4°C sinks and disturbs sediments in the benthic zone.
B) The surface water gets to 4°C only by cooling.
C) Fall turnovers and spring turnovers are exactly the same.
D) In fall turnover, dense water at 4°C rises and disturbs sediments in the benthic zone.

Accepted Answer

In fall turnover, the cooler water at the surface reaches 4°C, which is the temperature at which water is most dense. This dense water then sinks, mixing the water column and disturbing sediments in the benthic zone. This process is different from what is described in the other options, making A the correct choice.