How fast is ice made on lakes

In liquid water, these molecules arrange themselves randomly. In ice, the molecules align themselves in a regular lattice pattern and are more spread out, which results in ice being less dense than water. Because the crystal lattice allows a lot of light to pass through, the under-ice environment is surprisingly bright. Aquatic algae and plants can grow under lake ice.

Under turbulent conditions, ice freezes in a less orderly and transparent way than in calm water conditions. In turbulent conditions, initial ice formation is due to the formation of what is called frazil ice or fine ice crystals suspended in the water.

Frazil ice is usually smaller than one inch in length, and is shaped like sharp-pointed objects or small disks Pounder Frazil forms in the top inch or so of the moving surface water because the water there is colder than the water below - the same reason as clear ice forms toward the surface. Although clumps or rafts of frazil and sludge can accumulate in open water creating ice floes, the action of wind and current normally make this ice grow from the shore outward.

Because the frazil crystals are small and oriented in a variety of directions and the freezing of frazil incorporates gas bubbles and other materials, the primary ice that forms under turbulent conditions is usually less transparent and less smooth than ice formed under calm conditions. Again, this process continues until the surface of the water is covered with fast ice that is attached to the shore. The way ice forms is important for safety and ecology.

Weight, like my pickup truck, when applied to ice is supported by the water underneath it and not by the ice Ashton This way of thinking about ice stopped me cold for a moment. According to the legend, when Archimedes was sitting in a bathtub, he noticed that the water level rose by an amount equal to the mass of his body. From that observation he concluded for an object to be buoyant in water it must displace enough water to be equal to the mass of the object. In order for ice to float my pickup truck that ice must deform or bend downward to displace an amount of water equal in mass to my pickup truck.

If the ice is not stretchy or strong enough to deform and spread the mass of my truck out over a large enough area, the ice will crack and fail. Water will flood the crack and my truck will sink just like a boat with a hole in it.

Anyone who has watched ice form in the early winter knows that the process can go on for quite some time and is often discontinuous. As weather gets warmer and cooler, ice breaks apart and is pushed back together. Hummocked ice happens frequently along shores with wind exposure and can cause shore soils and material to be pushed inland. This ice-push, which is also called ice ride-up, ice surge, or ice ramping, can be quite violent and can cause severe damage to shore infrastructure, especially when ice breaks up under high wind stress.

Secondary ice is formed at the bottom of the surface ice by the clumping of frazil , the consolidation, freezing, and crystallization that results when heat moves up through the water toward the surface.

This often soupy ice layer can be created from a slurry of frazil or simply by the crystallization of new ice below the primary layer. Most of us have sunk through superimposed ice ice after the ice has been through a few freeze-thaw cycles. Superimposed ice ice forms when water has flowed out onto the surface of the primary ice or onto the snow covering primary ice.

The water can be from runoff from shore, shallow groundwater seepage from above the ice surface, rainfall, stream inflow, or surface snow and ice melted from the warm sun. Although superimposed ice ice freezes at the top, it sometimes leaves a considerable slush and water layer beneath it and above the primary ice. The principle explaining why ice floats is the same for what we erroneously call icebergs on Lake Superior and for the ice in your beverage.

To be classified as a true iceberg, the height of the ice must be greater than 16 feet above the water surface, the thickness must be 98 to feet, and the ice must cover an area of at least 5, square feet. Bergy bits are pieces of ice that are generally greater than 3 feet in height, less than 16 feet above the water level, and 1, to 3, square feet in area.

A bergy bit protruding just 3 feet above the water would have about nine times as much ice under the water as above it. A growler is a piece of ice roughly the size of a truck or grand piano that is low enough to the water that waves can wash over it. After ice-up there is usually a time period when ice cover looks good but is highly unsafe. People may also mistakenly assume ice thickness to be fairly uniform across a lake, but this is far from true Brown and Duguay Variations in ice thickness result from the way in which ice is formed and what happens to it over the winter.

The rate at which ice thickens depends on the temperature at the bottom of the ice where it meets the underlying water and the thickness of the ice. When ice is thin, heat from the water below that ice can escape to the air relatively quickly, which cools the water and allows ice to form.

When ice is thick, the heat of the water escapes more slowly into the air, which means the water stays warmer longer and it takes longer for thick ice to become thicker.

In-shore ice forms first so may be thickest once a lake is completely covered in ice. Bays and harbors that freeze rapidly in the early winter may also initially be thickest. As winter proceeds, ice thickness can tend to even out across a lake Bengtsson For example, when snow drifts onto thinner ice, it can slow the thickening of that ice through insulation. While the thicker ice continues to slowly grow thicker, the now-insulated thinner ice is also growing thicker more slowly.

Later in winter, in- and near-shore ice may be thinnest because of the inflow of groundwater and the activities of winter-active mammals. Black or crystalline ice tends to grow on the bottom of the ice cover whereas white ice grows on top of the ice due to the freezing of snow Bengtsson Caution is always advisable when working or recreating on ice. When my grandmother was a child, their family lost two teams of horses through the ice on the lake where I grew up.

I know exactly where they went in because, due to groundwater or other currents, that area which is about feet from shore still always has thin ice. Expand all. Anchor ice is usually formed under currents or stream flow when super-cooled pieces of frazil stick together and stick to the bottom forming a bottom layer of ice. This is formed frequently in streams and rivers when water is supercooled but also can form in lakes Kempema et al.

In all cases, release of anchor ice transports a lot of sediment and can cause impairment of power generation and habitat. These can be up to the diameter of a soccer ball and can be made of ice or ice covered in sand and sediment. They are likely formed as slush balls by wave action and rolled up the beach by waves or by tides in marine systems.

Thick pieces of clear, primary ice that have grown uniformly and appear black because light passes through them instead of being reflected back to the eye. Broken edges of black ice sometimes glow in the sun because they conduct light from behind them. Candle ice is rotten ice that leaves long, thin crystals as it melts. This is usually found when primary ice melts that was formed under very cold conditions Muguruma and Kikuchi But once ice begins to grow in thickness, it acts as an insulator between the water below and the air above.

In order for the water molecules to continue cooling down and change phase into ice crystals, heat from the water must be transferred somewhere else. Heat must either pass through the surface ice layer before being lost to the atmosphere, or be absorbed by the surrounding water molecules. As the surface ice thickens, it becomes harder for lake water to cool down quickly or warm up quickly and, as a result, it takes longer for lake water that is underneath the ice to reach its freezing point and turn to ice itself.

The thicker the sheet of ice, the more insulation the water has, and the slower these temperature fluctuations occur. Besides air temperature and ice thickness, the rate at which new ice is added to the bottom of the ice sheet depends on many other factors: wind action, solar radiation, cracks or fractures in the ice, and any snow or frost build up on the ice surface which also acts as additional insulation.

Despite this mix of environmental factors, there are still ways of determining how quickly the ice will grow. The colder the air temperature, the more likely it is that ice is able to grow! For example : if the maximum temperature yesterday afternoon was -5 degrees, and the minimum temperature overnight was degrees, the average of these two extremes is degrees.

Therefore, the ice today should be about an inch thicker than yesterday. However, there are a number of factors that influence this prediction.

Even a thin layer of snow or thick frost will dramatically slow the growth rate. I am not crazy enough to try 2. I am anticipating next weekend as well. From what I can tell I think it will freeze about. On the other hand, a little snow cover can make our temps go down further. Been checking a neighbors's small pond as my guage Didn't check today but got above 32 36 as I type this Starting tomorrow Encyclopedia of Lakes and Reservoirs Edition.

Editors: Lars Bengtsson, Reginald W. Herschy, Rhodes W. Contents Search. Ice Formation on Lakes and Ice Growth.

Authors Authors and affiliations Lars Bengtsson. How to cite. Description Ice forms when the surface water temperature drops to the freezing point. After heavy snowfall, the snow on the ice may become too heavy to be supported by the ice cover This is a preview of subscription content, log in to check access.