How would life in lake be affected if ice sank and lakes freeze from the bottom up?
How would life in lake be affected if ice sank and lakes freeze from the bottom up? If water instead froze from the bottom of a lake or river to the top, there would be profound ecological consequences. Shallow lakes would freeze solid; unless the plants, animals, and other organisms living there had some sort of adaptation that would keep their tissues from freezing, they would die.
How cold is dangerously cold water?
Cold shock can be just as severe and dangerous from water temperatures of 50-60F (10-15C) as it is from water at 35F (2C). Gasping for a breath or rapid breathing from sudden immersion can be triggered by water as warm as 77F (25C).
How long can you survive in a frozen lake?
In water that is around the freezing point, a person is likely to survive only 15 to 45 minutes with flotation and possibly up to an hour or so with flotation and protective gear before the brain and heart stop (Table 1). The surface temperature of Lake Superior in early to mid-summer is about 40 to 50 F.
Does lake ice melt from bottom up?
Because the ice acts like the glass in a greenhouse, the water beneath it begins to warm, and the ice begins to melt FROM THE BOTTOM.
How do fish breathe in a frozen lake?
“In most lakes there is enough oxygen under the ice that they survive the winter.” It's like having a bank account, he says: The fish gradually draw down their banked oxygen and hope there's enough to get through to spring. If not, some of them die.
Why water does not freeze at the bottom of lake?
The bottom of a lake do not freeze in severe winter. The reason is that ice is a poor conductor of heat hence once the surface is frozen no further heat is liberated or absorbed by water beneath ice. Therefore water below ice never freezes.
Why don t lakes freeze solid and why is that good for life on Earth?
If water were most dense as a solid, lakes would freeze from the bottom up, eventually freezing solid. In that case, little or nothing would survive in the lake. Most lakes and ponds don't completely freeze because the ice (and eventually snow) on the surface acts to insulate the water below.
Do fish survive in frozen lakes?
Do fish die in frozen lakes or in lakes that are partially frozen? Since fish are cold-blooded animals, they can survive because they are able to regulate their body temperature to match their environment. However, they could die if a body of water freezes over completely and remains frozen for an extended period.
Why deep lakes do not freeze solid from the bottom to the top?
The gravitational weight of all the water higher up in the lake presses down on the water deep in the lake. The pressure allows the water near the bottom of the lake to get cold without expanding and rising. Because of the pressure, the water at the bottom of deep lakes can become cold without freezing to ice.