Question

During summer the surface water of the lakes with high temperature is separated from the cold bottom layer by mid water, called as
A)Metalimnion
B)Thermocline
C)Thermal stratification
D)None of the above

Answer 1

Hint: The density of water relies over its temperature. The colder the temperature, less dense the water gets. The Lake prefers to form distinctly separate thermal sheets during hot weather. Weather influences the water temperature in the lake each day and season.

Complete answer:
The stratified lakes contain three different layers, the epilimnion, composed of the top warmer layer, the metalimnion: the mid layer, which can differ in depth for the day and the colder hypolimnion, which extends to the bottom of the lake. The middle layer is the water transfer zone between both the warm epilimnion and the cold hypolimnion, termed the metalimnion. The metalimnion is a point where the shallowest of the cool water in the hypolimnion slowly heats up until it is mixed into epilimnion. All through summer, crashing waves force the water in the epilimnion to blend further and further, gradually adding hypolimnetic water through the metalimnion. Depending upon the season, latitude, and turbulent air mixing, metalimnion is a semi-permanent aspect of the water body in which they exist, or may evolve temporarily in reference to phenomena like radiative heating/cooling of surface water throughout the day.

The densest level is the warm part of the earth, called the epilimnion. The epilimnion is indeed a surface of water which connects with wind and sun, keeping it the warmest and holding the most dissolved oxygen. Even though dissolved oxygen doesn't really serve a key role in the stratification and retention of the lake, it is vital for all marine animals in the lake that demand oxygen to live. The lowest layer is the cold, dense water at the bottom of a lake called hypolimnion. Hypolimnion mostly persists about 4°C across the year, seldom receives any direct warmth from the sun and is detached from the air on the surface of the sea. Hypolimnion contains a low percentage of dissolved oxygen but can also become anoxic (null dissolved oxygen) whenever the lake is thermally classified.

Hence, the correct answer is option (A)

Note: Factors that may influence the depth and density of the metalimnion include periodic temperature changes, latitude and regional environmental influences, such as tides and currents. If the temperature begins to decline, the surface water will also get close to freezing and also the lake/ocean will start to freeze. A new metalimnion is developing where densest water sinks to the bottom, and less dense water gets to the surface.