Next came the time of freeze-up. It’s always a dangerous situation for experienced and novice anglers, eager to open the season with thin ice. The fact that the quality of the ice cover varies greatly depending on the type of habitat, from its size and from the average depth and even the distance from the shore and the direction and force of the wind in the process of freezing water. So again and again we have to pay attention to the basic rules of safe behavior on the young ice.
The risk fishing on the first ice is that the ice is almost never ideal. Usually there are several, short periods of education temporary ice cover, which, not having reached sufficient strength, then eroded by rains, damp fogs weakened and broken by the wind. In the best case, the period of Pervolia can be very short — one or two quiet nights with hard frost. In addition, pergolide if it has developed, can be divided into some phases: parvoleta (thin, but not collapsing ice), strong at least in places, the ice reliable ice, entirely covering some bodies of water and anywhere suitable for fishing.
It is clear that not only different bodies, but even in one of these phases spaced both in time and in the waters, sometimes significantly. Therefore, when planning the first exit on the ice, you must know what is happening in a particular reservoir depending on its type and the prevailing weather situation.
Now a few words about how the process of freezing the surface of the water that it is affected and what quality of ice is to be expected in a certain situation. So, come to the stable cold with negative average daily air temperature. The water cools from the surface, and when the top layer cools to a temperature of plus 4 degrees at which the liquid abruptly becomes the most dense, water, virtually no mixing up, falls down, pushing up the warmer and lighter water.
Thus, there is a vertical circulation and a very slow mixing of the entire water column. This process of convection is gradually attenuated as approaching the total temperature to 4 degrees. However, it is not terminated — the bottom layers are constantly receiving heat from the bed of the reservoir, which in winter is always a little warmer water, otherwise the ponds froze to the bottom, and the ice would grow above and below that typically occurs in climates with permafrost.
Gradually the bulk of the water will take the temperature 4 degrees. Thereafter, further cooling to 0 degrees is the freezing point. Supercooling below 0 ° leads to the formation of ice.
But in nature water is a solution of salts and mikrosveta, varying in composition in different water bodies, which usually reduces the temperature required for the formation of ice, and it is everywhere uneven. Additionally, the nature of the ice depends on the weather, and the type of water body: big or small, deep or shallow, or stagnant. The formation of ice is also influenced by the fluctuations of water level, a substantial amount of warm household water, continuing in some places shipping.
If the ice is quiet in cold weather, the ice is almost uniformly covers the whole pond, rising from the shores, especially in areas of shallow water. When the process of the formation of ice is accompanied by strong winds, the formation of ice cover on open spaces, large bodies of water stay long. There are steep waves break and carry fragile thin pervalidus and knocked him to the leeward shore, where with a fairly strong frost, quickly grasping the fragile building material, can be formed very thick, but less durable than solid ice, wide rim. The other rim of solid ice will rise from the windward coast, and the steeper, the higher the Bank, the more transparent pavings will be on the water.
When remission of the wind, unless there is a sudden thaw, the two rim flanges quick connect, as well mixed and chilled water is ready to freeze. However, the angler still long to remember where the ice stood at the beginning — there it is thicker and stronger. It is clear that over large depths, where the large mass of water, cool it will last longer and ice formation will occur later than in small places.
On the rivers, their features freeze-up: due to the flow of water is constantly mixed throughout the volume, and hypothermia occurs throughout the moving mass that you need more time, so the ice on the river rises somewhat later than in the ponds with stagnant water. However, the water in the rivers under the ice generally colder than on lakes and reservoirs, and, paradoxically, a further increase of ice on the river is faster. But strong currents, ice forms later than in a weak flow.
Conditions for safe fishing, the most robust of pure, solid ice, formed from freezing the top layer of supercooled water. However, to fish with such ice is meaningful only over a large depth, where comes a little light, and then the fish are not shy. So he’ll be safe when you reach a thickness of at least 5 centimetres — only in this case the “glass” ice reliably one person, but groups it together is impossible.
The strength of the ice cover increases linearly with increasing thickness and with decreasing temperature. But here we must imagine that the temperature of the ice thickness varies: it is equal to atmospheric at the top, and the bottom — corresponds to the freezing point of water, i.e. about zero degrees. And since the temperature coefficient of linear expansion of ice is huge (for example, five times greater than that of iron), and many must have seen as broken durable vessels with frozen water, it becomes clear that similar processes are inevitable and with the ice on the pond.
The growth of ice thickness with different temperature layers experiencing expanding the load as a transverse and longitudinal direction. Therefore, when a sudden warming or cooling in ice on the ponds burst with a deafening roar, and it will diverge long cracks. In addition, the huge water areas of lakes and reservoirs these cracks, on the one hand, cause the formation of ice ridges, and on the other (to compensate) — wide leads, which can easily fall, especially after covering the open water, snowfall.
Cracks in the ice, if they are readable, very valuable to the observant angler when to understand the mechanism of ice formation. The fact that in the beginning of winter, when the ice is not everywhere of equal thickness, stresses are localized in narrow zones of the joining of thick and thin ice cover, that is where shallow water quickly changes at depth. Thus, the bottom drop offs, which often holds fish, you should look at old and wide, running generally parallel to the main direction of the cracks. While the deep side of the pond will be determined by usually located close to the steep Bank of the fissure, and Vice versa.
The important thing to remember in our variable winter weather, the picture of freezing of ice is strongly influenced by the thickness of its snow cover, which performs the role of coats. It is known that the thermal conductivity of snow up to 30 times less than that of ice (a lot depends on the snow density), thus, snowfall, depending on their intensity, it is necessary to make plans for a visit to the pond a serious amendment.
It should also be understood by referring to the first, fragile ice as it responds to load. Anglers with experience say that young ice will not deceive, will not fail, and time will tell about the dangers of a loud Bang and crack. Applied to thin ice load (the angler on the ice) causes a deflection (deformation) in the form of a bowl. At low load, the deformation is elastic, and the bowl expands symmetrically around the perimeter. If the load is above the elastic limit, it will start plastic deformation of the ice and the Cup deflection will become faster increase in depth than in width — this is the beginning of destruction of ice. In quantitative terms, it would look like. For the most durable transparent ice of the Central deflection of it at a depth of 5 cm of cracks will not cause; the deflection of 9 cm leads to increased cracking; deflection of 12 cm causes through-cracking; at 15 cm ice falls.
Under load the cracks in the ice emerge as radial outbound from the point of application and concentric around this point. Radial cracks only warn about insufficient strength of the ice, which requires extreme caution on it. But if to radial cracking concentric cracking is added, followed by a characteristic creaking sound, need to slide step to immediately leave the dangerous area. In particularly critical situations it is better to go on the ice to increase the area weight distribution across the surface, and crawl in the opposite direction.
© 2016, z-news.link. All rights reserved.