Why water in lakes and ponds do not freeze at once in cold countries?

Answer. Water in lakes and ponds do not freeze at once in cold countries because the specific latent heat of fusion

latent heat of fusion

The enthalpy of fusion of a substance, also known as (latent) heat of fusion, is the change in its enthalpy resulting from providing energy, typically heat, to a specific quantity of the substance to change its state from a solid to a liquid, at constant pressure.

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Enthalpy of fusion - Wikipedia

of ice is sufficiently high (= 336 J g^-1). The water in lakes and ponds will have to liberate a large quantity of heat to the surrounding before freezing.

Why in cold countries water in lakes and ponds do not freeze at all at once?

In cold countries, water does not freeze all at once in ponds and lakes. This is due to the fact that specific latent heat of fusion of ice is 336Jg−1, so as to freeze water, a large quantity of heat has to be withdrawn, hence it freezes slowly.

Why in cold countries ponds freeze only at the surface?

Since ice is a poor conductor of heat so ice now prevents the flow of heat from water of ponds to the atmosphere. Thus,temperature of water in contact with ice is at 0° C,while the temperature of water layers below the ice gradually increases to 4°C.

Why does life survive in a lake or pond when it freezes over?

A lake more than one meter deep will never freeze completely, meaning there's plenty of space for animal and plant life to survive the winter. Added to which, the dense water in the deeper sections of the lake has a much higher oxygen content. This allows fish and other life to make it through to the spring alive.

Why does water not freeze in the winter?

The answer again lies in physics. For any stream of moving water to freeze, it takes more than a simple drop in temperature. Heat must be lost at a rate that exceeds the rate of replacement: the rate at which flowing water is replaced by water of potentially higher temperatures upstream.

Why do Lakes freeze from the Top to Bottom?

Why does a lake not freeze?

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.

Why oceans do not freeze Give two reasons?

The presence of salt and the high volume of water prevents it from freezing. And, the water consisting of no salt and less volume of water freezes under the lower temperature. The salt in the ocean water reduces the freezing point.

How fishes can survive in the extreme winter when ponds and lakes are frozen?

Underneath the frozen upper layer, the water remains in its liquid form and do not get the freeze. Oxygen is trapped beneath the layer of ice. As a result, fish and other aquatic animals find it possible to live comfortably in the frozen ponds.

Can a pond completely freeze?

“Winter kill” refers to the death and die off of fish, frogs and turtles after a hard winter where a pond or small lake becomes completely snow covered or freezes over completely, preventing the natural exchange of gasses. There is only so much water in a pond containing oxygen.

How cold does it have to be for ponds to freeze?

First, a pond can stay unfrozen even if the air temperature is below the freezing point (32 degrees F).

Why ice freezes only on surface of lakes?

The upper surface of the lake is in contact with the cold environment and starts to freeze. The density of ice is less than that of liquid water. Therefore, ice floats on the surface. Thus, the ice layer at lower temperature floats over the water below it.

Why is it possible for the surface of a pond to freeze even though the water underneath is fluid?

In order for water to freeze, it must reach a temperature of 0oC . This occurs at the surface of a lake, which is why it freezes. However, water, being a special molecule, expands when it freezes, rather than contracts, meaning that the ice on top of the lake is less dense than the water underneath it.

Why does water freeze only on top?

The reason water freezes from the top down is because, unlike almost everything else, water gets less dense when it freezes. This is why ice cubes float in a drink.

Why do the surrounding become pleasantly warm when freezing starts in cold countries?

So, when the water which is in liquid state freezes, then it releases heat to the surroundings. It's a exothermic process where heat is released to surrounding. Hence the surrounding becomes pleasantly warm when water in lake starts freezing in cold countries.

When ice in a frozen lake starts melting its surrounding becomes very cold?

When ice in a frozen lake starts melting, its surrounding becomes very cold because the heat energy required for melting the frozen lake is absorbed from the surrounding atmosphere. As a result, the temperature of the surrounding falls and it becomes very cold.

How do fish survive winter in ponds?

Because warm water sinks in very cold freshwater, fish in these water bodies often gather in groups near the bottom. Some species, like koi and gobies, may burrow into soft sediments and go dormant like frogs and other amphibians, but most fish simply school in the deepest pools and take a "winter rest."

Do ponds freeze in winter?

Garden ponds, as well as all-natural bodies of water, will always freeze from top to bottom because the water exposed to the air loses its heat much faster in comparison to the water at the bottom. As the surface water loses its heat it begins to freeze, which creates a layer of ice on the top of the pond.

Do fish freeze in lakes?

Synopsis: How do fish survive in frozen lakes and the waters of Earth's icy polar regions? Freshwater fish trapped in lakes benefit from the properties of water itself, which cause stratification that insulates the lower layers of water. Their cold-blooded metabolisms slow, but they don't freeze.

At what temperature do lakes freeze?

Once the surface water falls to 32 F, it freezes. The freezing then spreads downward into the lake and the ice thickens. Unless the lake is very shallow, you will find liquid water below the ice.

How do animals and plants living in lakes and ponds in snowy regions survive during winter?

1)most of them hibernate. 2)few have thick fur for protection. 3)fishes are coldblooded so they easily adapt. 4)frozen sheet of water in a lake maintains the warmth of the lakes.

How fishes survive in ponds even when the atmospheric temperature is below 0 C?

Until the water touches maximum density at 4oC, the circulation set up. Drop in temperature cause the top ;ayer to expand and remain at the top till it freezes. Hence though the upper layer is frozen, the water at the base is at 45oC, hence the fishes an easily survive.

Why do fish survive in cold water?

Fish living in cold climates have evolved an adaptation to keep from freezing: antifreeze proteins. Arctic and Antarctic fish families have these proteins in their blood. They're part of why these fish can live in waters that other fish can't.

Why is the ocean blue?

The ocean is blue because water absorbs colors in the red part of the light spectrum. Like a filter, this leaves behind colors in the blue part of the light spectrum for us to see. The ocean may also take on green, red, or other hues as light bounces off of floating sediments and particles in the water.

Did the oceans freeze during the ice age?

It looks more and more as though in the past, however, cold had even more dramatic an impact than the putative warming is predicted to be having now. Glaciers that came as far south as New York and Wisconsin, as some did 18,000 years ago, were not the problem. No, the whole earth — including the oceans — froze over.

At what temperature would a human freeze instantly?

At 82 F (28 C) you can lose consciousness. Below 70 F (21 C), you are said to have profound hypothermia and death can occur, Sawka said.