Every winter fishing fisherman is simply obliged not only to know, but also to understand the properties of the ice cover of all types of reservoirs under various circumstances, since this is directly related to the safety of the person who went fishing. Moreover, one of the most unstable characteristics of ice is its strength. It is determined by many factors, including the thickness of the ice, its temperature, structure and appearance.
Often, at the beginning of winter, there are prolonged thaws, accompanied by rains or sleet. During such periods, the ice cover is formed gradually, mainly in the intervals between cyclones. And it is worth noting that its thickness grows both from above – due to freezing of the snow-water “porridge”, and from below – due to crystallization of water located closer to the surface of the reservoir.
Ice formed under such circumstances has a multilayer structure and a dull color.
Remember! Such ice is about 2 times weaker than the one that is transparent like glass (that is, it can withstand half the static load).
That is why it is highly discouraged to go out on an opaque ice cover. This is permissible only if it reaches a thickness of 10 cm and in the presence of a negative air temperature. This is especially true for anglers, for the simple reason that they quite often tend to get exactly on such areas of ice. And all because the fish accumulates and, accordingly, bites much better in such places.
As mentioned earlier, clear and transparent ice is much stronger. It is a kind of crystalline monolith, which is formed as a result of hypothermia and subsequent freezing of the surface layers of water. However, there are also some nuances here. For example, fishing in places with such ice is quite problematic and is possible only where the depth of the reservoir reaches significant values. After all, this means that only rare sun rays reach the level of the accumulation of fish, which are not able to scare them away.
That is why even such strong ice should not be stepped on until it reaches a thickness of 5 cm – only then the ice is able to withstand one person. Well, in groups it is still prohibited to be on it.
The strength of the ice sheet directly depends on its thickness and temperature. But here one should take into account the fact that the ice temperature at the surface differs significantly from this indicator at depth. So, at the very top, its temperature corresponds to atmospheric, but at the bottom it is already equal to that at which water freezes, that is, 0 degrees Celsius. With a gradual increase in the thickness of the ice cover, its layers, which have different temperatures, begin to experience an expanding load of both longitudinal and transverse directions.
That is why, during sudden cold snaps or warming, the ice on all kinds of water bodies bursts, creating long scattering cracks and accompanied by a deafening roar. And if this happens on reservoirs or huge water areas, then ice torsos are almost always formed on one side, and on the other, apparently to compensate, there are wide openings. So, in the latter it is quite easy to please, especially in those cases when a snowfall covering the water passed on the eve.
Many people think that cracks on the ice are formed chaotically, haphazardly. However, it is worth remembering the mechanism of ice formation and everything does not look so simple anymore. At the very beginning of winter, before the ice becomes of the same thickness over the entire reservoir, the greatest stress is localized in narrow joint zones between the thin and thick ice cover (here the depth of the reservoir increases sharply). Experienced fishermen know the fact that fish are kept on bottom dumps, which should be looked for along the oldest, often parallel to the riverbed, cracks. Moreover, the deep part of the reservoir, in this case, is determined by the crack that is closest to the steep bank.
In order to at least roughly imagine what is the thickness of the ice at the moment on the reservoir, it is necessary to know its possible increase during the day. It depends on the thickness already available and on the air temperature. This is noticeable in the following example: imagine that the ice already reaches 10 cm, then it will add about 4 cm if the frost is -5 ° C; 6cm – if -15 ° C; 8cm – if -15 ° C; 9cm – if -20 ° C. However, with the initial ice thickness of 25-30cm, the daily increase will decrease by about 3.5-4 times. More precise figures cannot be provided, as this is also influenced by the quality of the local water.
Undoubtedly, the thickness of the snow cover covering the ice plays an important role in the overall picture of ice freezing. It is well known that the thermal conductivity of snow can in no way be compared with ice – it is about 30 times less. That is why the calculations should be adjusted depending on the intensity of snowfall in a given period of time.
It is important to learn how to determine by the type of the earliest fragile ice how it will react to the load in the future. Experienced fishermen claim that young ice has never deceived or let them down. On the contrary, he warns of danger in time, emitting a loud crack and launching multiple diverging cracks.
If we apply a force equal to the mass of one angler to thin ice, then it deforms (bends) in the form of a bowl. If you act with less force, the deformation will be elastic and the bowl will expand symmetrically around the entire perimeter. In those cases when the load on the ice exceeds the elastic limit, the deflection more often increases in depth faster and ice begins to break.
Under the action of gravity on ice, both concentric (around the point of application) and radial (starting directly at this point) cracks are formed in it. The latter only inform us that it is necessary to be extremely careful, as there is insufficient ice strength. But when concentric cracking joins the radial cracks (this is accompanied by a specific creaking sound), it is necessary to urgently leave the dangerous area using sliding steps. In the most critical situations, you should slowly lie down on the ice (the area of mass distribution increases) and only then begin to slowly move to a safe place.
In addition, it is imperative to study and, most importantly, remember a few more important rules regarding safe behavior on ice:
- Don’t go ice fishing alone
- Before each step, check the ice with a pointed ice pick. But you do not need to break the ice with it directly in front of you, it is better from the side.
- Always maintain a distance of at least 3 meters in relation to other anglers.
- Keep away from potentially dangerous areas where you can see frozen algae or driftwood.
- Do not walk near fresh cracks or areas of ice separated from the main body.
- If a fountain of water begins to beat from the hole made, you need to leave this dangerous area of ice as soon as possible.
- You should always have with you reliable means of rescue and belaying (wide board, long pole, cord with a load).
- And most importantly, you should never combine fishing with drinking.