Question

Thermocline is
A. Part of upper atmosphere in which temperature increases with height
B. Part of upper atmosphere where temperature declines with height
C. The layer of water in a lake, where temperature decreases rapidly with increasing depth
D. The layer of the earth, where temperature increases rapidly with increasing depth

Answer 1

This layer is found in most large water bodies, including lakes and seas that divide the upper and colder layers of sunlight below. That is a variable layer of water, where a small but distinct layer of fluid has a significantly different temperature than the fluid above it.

Complete answer:
The ocean has three primary layers:- the surface of the ocean, which is usually warm; the deep ocean, which is cooler and denser than the surface of the ocean; and the sediment of the sea. The upper surface layer is called the epipelagic zone. This layer interacts with the wind and the waves that blend the water and spread the warmth. The thermocline is at the base of this layer. Thermocline is the intermediate layer between the colder mixed water on the surface and the colder deep water below. In thermocline, the temperature drops quickly from the temperature of the mixed layer to the much cooler temperature of the deep water. Thus, at this layer, there is a rapid shift in temperature. Since the surface and deep ocean layers have very different densities, these ocean layers do not mix easily.

Thus, the correct answer is option C i.e., The layer of water in a lake, where temperature decreases rapidly with increasing depth

Note: In the oceans, the depth and strength of thermocline varies seasonally or yearly. It is semi-permanent in the tropics, seasonal in temperate regions while in the polar regions it is shallow to non-existent where the water is cold from the top to the bottom.