Answer:
decrease in size
Explanation:
An ocean surrounded by many trenches may "decrease in size."
This is evident in the formation and process of subduction and sea-floor spreading, which has a great impact on how the oceans form in terms of size and shape.
According to research, it is believed that the sizes of Earths oceans are defined by the speed at which new crust is being developed, right from the mid-ocean ridges, and the speed at which old crust is being swept off at deep-ocean trenches
