A rapid change in temperature with depth is kn own as a.

Thermocline.

Explanation:

An ocean is a body of salt water which covers approximately 70% of the Earth's surface. About 97% of the Earth's water is comprised of ocean and as such it is the most prominent and defined feature of the Earth. There are basically four (4) categories of an oceanic basin and these are;

1. The Pacific ocean.

2. The Artic ocean.

3. The Atlantic ocean.

4. The Indian ocean.

A rapid change in temperature with depth is known as thermocline.

Basically, it is considered to be a thin but distinctive water region in a large body of fluid that is thermally stratified such as an ocean, in which temperature changes rapidly with an increasing depth.

This ultimately implies that, the temperature of water decreases rapidly (drastically) as the depth of water increases.