When does ice not float?

Answer 1

The ice would sink, and, particularly in the higher latitudes, the sinking ice would allow more ice to form in winter. Eventually, the northern and southern oceans would be solid from the surface to the bottom, as would northern and southern lakes, and slower moving rivers.

It depends on how the ice formed:

# Land ice. If you had a glacier sliding off into the ocean (like on Greenland), then the ice would be fresh water (no salt). Fresh water is lighter than the salt water in the ocean, so the glacial ice may continue to float. # Sea ice. If you are just talking about normal lakes and oceans freezing because of cold air, then convection currents in the water would prevent any ice from forming at the top. Which would mean you would not have an 'sinking ice'. No ice would form at all until the entire water body cooled down to 0°C. That would mean that none of the oceans would freeze at all. They would remain open water even during cold, long winters. Small lakes would freeze solid (and take much longer to thaw in the summer), but larger lakes like the Great Lakes on the US/Canada border would likely remain completely ice free. There would be some ice near the shores of both the large lakes and oceans (where it got shallow enough to freeze solid). Most the aquatic life in the smaller lakes would die. Large rivers would remain ice free, but smaller rivers would freeze solid. If the water source of the smaller rivers continued producing (like an under-ground spring), then you would end up with an icicle effect where the water keeps freezing over top other layers of ice and the river would become this enormous mound of ice resembling the Hawaiian volcanoes. It is possible that more ice could form in natural bodies of water but claims of freezing from bottom to top are wildly speculative and unjustified by analysis in my opinion. The following considerations from the disciplines of thermodynamics and heat transfer are the primary determining factors.

Sinking ice brings about two effects at the surface. (1) An increased temperature difference between the water and the atmosphere due to warmer water replacing the sinking ice. This effect would cause greater heat transfer from the water to the atmosphere. (2) A reduction of thermal conductivity across the layer formerly occupied by the ice since the thermal conductivity of water is lower than that of ice by almost a factor of four near freezing temperature. This effect would cause the heat flow from the water to the atmosphere to decrease. If the former effect is predominant then there will be an increased heat flow from the surface to the atmosphere. If it is also assumed that any change in the heat flow from the earth into the body of water as a result of the ice falling to the bottom is small compared to the heat transfer at the surface then in accordance with the First law of thermodynamics, there would be increased cooling of the body of water under the condition of ice sinking over the condition of reality, floating ice. Thus under these assumptions, more freezing of natural bodies would occur if ice did not float.

Answer 2

If ice didn't float, sea level would be approximately 220 feet higher since all the ice on Earth would sink and displace an equal amount of water. Therefore most of the land on Earth would be underwater and life as we know it would not be possible.

Answer 3

The fact that ice floats is of huge biological significance. Because only the top layer of any large body of water freezes, the floating ice will insulate the unfrozen water, allowing for organisms to live in warmer water below. If water was more dense as a solid, and would therefore sink; ponds, lakes, and even oceans and seas would freeze solid, with only a few inches of the top layer thawing in summer. This would effectively stop life from taking root from the beginning, as well as ending life on earth as it is known today. I could spend an hour writing about all the consequences of ice being more dense than water, but a good quicky is that fish would die in lakes and ponds. When ice forms on top of a lake or pond it creates an insulating layer between the outside air and the water beneath it that prevents the entire pond or lake from freezing solid. Were ice to form on the surface and then sink to the bottom, the pond or lake would eventually freeze solid and all the fish would die.

Answer 4

Well, consider this water is the most dense around 4 degrees Celcius/40 degrees F. From there getting warmer it because less dense and when it is lower than 4 C, water stays around the same density because of its ice state. If ice was heavier than water and didn't float it would be cataclysmic, therefore being more dense than water and causing a rise in water level. Imagine the Arctic circle there is no land mass beneath it in the winter months there the ice would sink to the bottom of the ocean and cause water levels to rise drastically.

Answer 5

Never. Ice will always float. Let me explain...

First, let's take a look at why anything floats. Then, let's examine why ice floats on top of liquid water, instead of sinking to the bottom.

A substance floats if it is less dense, or has less mass per unit volume, than other components in a mixture. For example, if you toss a handful of rocks into a bucket of water, the rocks, which are dense compared to the water, will sink. The water, which is less dense than the rocks, will float. Basically, the rocks push the water out of the way, or displace it. For an object to be able to float, it has to displace a weight of fluid equal to its own weight.Water reaches its maximum density at 4°C (40°F). As it cools further and freezes into ice, it actually becomes less dense. On the other hand, most substances are most dense in their solid (frozen) state than in their liquid state. Water is different because of hydrogen bonding.

A water molecule is made from one oxygen atom and two hydrogen atoms, strongly joined to each other with covalent bonds. Water molecules are also attracted to each other by weaker chemical bonds (hydrogen bonds) between the positively-charged hydrogen atoms and the negatively-charged oxygen atoms of neighboring water molecules. As water cools below 4°C, the hydrogen bonds adjust to hold the negatively charged oxygen atoms apart. This produces a crystal lattice, which is commonly known as 'ice'.

Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a liter of ice weighs less than a liter water. The heavier water displaces the lighter ice, so ice floats to the top. One consequence of this is that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over. If ice sank, the water would be displaced to the top and exposed to the colder temperature, forcing rivers and lakes to fill with ice and freeze solid.