2006-09-14 22:15:38 · 8 answers · asked by ??? 1 in Science & Mathematics ➔ Physics
the temperature of the cold surroundings forst affects the top layer. It freezes. Water expands on freezing. So, its density for a given mass decreases. Hence, it floats on the liquid water below(which has a higher density) and protects the water under it from freezing. If water had a property of contraction on freezing, the frozen layer would sink and finally the whole water body would be frozen due to the coldness
It is due to the expansion of water on freezing, that marine animlas are able to survive in winter.
2006-09-15 00:12:33 · answer #1 · answered by Sachin 2 · 0⤊ 0⤋
You are correct that the icy surface insulates the water trapped below; and the thicker the ice the greater the insulation. Every fall the entire contents of a lake must turn over (surface water cools and sinks and bottom water rises) before the first ice can form because cooler water is more dense but ice floats. The ground water that still enters the lake perhaps through springs is at the average temperature of all the water that entered the ground during melt seasons. The average temperature can not be below freezing because ice can not enter the ground and flow. Therefore the water trapped below the surface ice often has a heat source from the ground water. Also the earth is constantly losing heat from its interior (lava and magma) through the crust which supplies the trapped water with some heat. The only way for the heat to escape is up through the increasingly thick ice.
2006-09-15 00:13:58 · answer #2 · answered by Kes 7 · 0⤊ 0⤋
Water is quite a unique liquid in that it is at its most dense at a temperature above its freezing point - about 4C. This means that ice will float in cool water, as you probably know from experience. Bubble of air within the frozen ice can also help this effect.
The layer of ice then serves to insulate the water below it, preventing it from freezing rapidly.
This feature of ice is important. If frozen water sunk, then ice would continuously freeze on the surface of the oceans and then sink to the bottom of the sea. Eventually entire oceans would be frozen, and the world would be a very different place!
2006-09-14 22:24:22 · answer #3 · answered by robcraine 4 · 1⤊ 0⤋
Because ice is less dense than water and floats to the top. The water at the bottom of the pond is actually 4 degrees celcius.
2006-09-14 22:28:33 · answer #4 · answered by uselessadvice 4 · 0⤊ 0⤋
most liquid expand when heated and contract when cooled. However, water behaves differently at temperatures between 0 degree celcius and 4 degree celcius. When heated from 0 degree celcius to 4 degree celcius, instead of expanding, water contracts to its minimum volume at 4 degree celcius. The irregular or anomalous property of watee allows marine life to stay alive underneath frozen lakes and ponds
2006-09-14 22:22:37 · answer #5 · answered by gal 1 · 1⤊ 0⤋
Pool, in trouble-free terms. The lake water right this is merely too grimy. we live in the midst of the country, so the sea is merely too far-off, yet as a toddler, I enjoyed the sea. a tub is rather no longer great adequate. The pool water should be very sparkling.
2016-12-12 08:50:13 · answer #6 · answered by Anonymous · 0⤊ 0⤋
YOU GET A CONSTANT circulation OF warm and cold water from the surface to the bottom. colder water becomes more dense (4 C maximum density) and it "falls" to the bottom where it is warmer . it "heat" and travels back to the surface nas so on.
2006-09-14 22:42:06 · answer #7 · answered by Emmanuel P 3 · 0⤊ 0⤋
due to the ANOMALOUS expansion of water
2006-09-14 22:16:51 · answer #8 · answered by h b 4 · 0⤊ 0⤋