What would happen to the oceans if surface runoff and groundwater flow were reduced (for example, by the growth of ice sheets during an ice age) ?

The ocean would eventually become smaller in size

Explanation:

The earth is covered by about 70% of the water bodies. This water is regulated by maintaining a variety of processes, and this commonly forms a cycle, which is known as the water cycle.

The surface runoff and the flow of groundwater are two of the important processes that add water to the oceans and seas. If these processes are reduced then it will directly affect the oceans. It is because the water will not be contributed to the seas and oceans, thus there will be a reduction in the amount of total water in the oceans. Therefore, it will eventually lead to a reduction in the size of the oceans.