Compared to the water in all surface oceans combined, what is the estimated scale of the water held in the transition zone?

Answer

Nearly three times the amount

The sheer volume of water suggested by the saturation levels in the transition zone implies that the total amount of water held there could be equivalent to nearly three times the amount found in all surface oceans combined.

Compared to the water in all surface oceans combined, what is the estimated scale of the water held in the transition zone?
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