In the old days in Russia, that autumn came to an end and the frosty winter begins, they judged by how the rivers froze. What is freezing, everyone knew - this is the time when the ice on the river stopped and covered with a thick white crust the entire surface of the reservoir, from coast to coast.
How does freezing start
In late autumn (usually at the end of October or in the middle of November), the cooled water in the river becomes dark, almost black, and along the coast, where there are the smallest places, thin plates of ice appear. They look as if they accidentally caught on shore. Such ice is called "Zabereg". And this serves as a sure sign - the time of freezing began.
Now it was already possible to wait when small flat ice floes floating brightly against the dark background of the river floated on the surface of the river. In some ways, they resemble frozen fat on the surface of a cooled soup, for which they are sometimes called: "ice lard."
What is ice formation can be understood by seeing how the sludge forms ice floes
And when the thick wet snow starts, its flakes will not even melt in the water. Now they will begin to go with the flow further, making the river in places similar to thick porridge. By the way, this porridge also has its own name - "snow".
Ice lard gradually sticks to the snow and turns into loose lumps of ice saturated with water. This intra-sea ice - sludge - is not only located on the surface, but falls already into the very thickness of the water, sometimes forming whole carpets and wreaths.
After a couple of days, the sludge freezes and forms ice floes. At this time, you can see the autumn ice drift.
But these ice floes, unlike the spring ones, do not melt, but become thicker and larger. Frost grabs them, connecting with the barriers. At this time, the movement of ice freezes, which means that the ice formation on the river has finally taken shape. The course of the river stops - it is drawn in by a thick ice crust.
Freezing is not on all rivers
If the freezing conditions are facilitated by calm frosty weather, then the ice is obtained of almost uniform thickness and grows from the coast. But if a strong wind falls during the freezing-up, then it can linger for a long time in the open spaces of large rivers or lakes - strong waves break and blow off the fragile first ice, preventing it from building up and strengthening.
By the way, the wind can drive such ice to the leeward, where in severe frost, fragile ice becomes a solid thick rim, which later will be chosen by fishermen - it is convenient for winter fishing.
As we said at the beginning of the article, the time when the river freezes was always considered the beginning of winter. But nowadays, in cities, due to the fact that the warm effluents of industrial enterprises are lowered into the rivers, you can never know what freezing is. Indeed, in cities, rivers either freeze very late, or they never freeze throughout the winter.
Together with ice formation on rivers, or rather, in places where a fast current flows into a reach with a slow stream or where there is a reverse flow behind the capes, the appearance of ice hummocks can also be observed. They are formed by accumulating ice. And sometimes (especially in the northern regions of the country) hummocks can reach a height of up to three meters.
What are wormwoods and lanes
Most of the rivers in Russia can demonstrate what freezing is, but sometimes on areas covered with solid ice you can also see areas where it is completely absent. Such places are called “wormwoods” or “lanes”. They are formed either where there is warm groundwater, or in places where the river flows from the lake, receiving warmer lake water.
Sometimes such wormwoods can be very impressive. For example, on the Emetsa River, which is a tributary of Onega, a space of 100 km does not freeze, despite the fact that the winter in those places is very severe.
Non-freezing areas are also formed in places where the river has a strong current or rapids and rapids. Most often, this can be observed on the rivers of Karelia and on mountain rivers in Siberia.