Landslides, landslides, rockfalls and mudflows are not only very dangerous natural geological phenomena, they are also associated with unreasonable and dangerous human activities.
Landslides, landslides, rockfalls and mudflows, precautions, human behavior in the danger zone.
Landslides are the displacement of rock masses down a slope under the influence of gravity. They are caused by both natural (washing out the base of the slopes, earthquakes), and artificial reasons (road construction, deforestation, etc.).
Rockfalls come in two types. The first type is the movement of stone scree on a steep slope, the second is the free fall of stones from steep sections of rocks. At the foot of the slopes they create screes of various sizes and steepness, within which most of the stones stop. Rockfalls are especially widespread and almost universally distributed on steep slopes (usually with a slope of more than 30 degrees). In this case, the movement and fall of not only single, but also whole groups of stones of different sizes often occurs..
Rockfalls occur both when people are carelessly moving along the slope (sometimes a strong scream or shot is enough for this), and due to natural reasons, for example, during the daytime. The stones fall when thawing soil frozen overnight, washing out or blowing out black soil from under them, and pushing them with tongues of sliding soil. The largest rockfalls occur in heavy rains.
The volumes of rockfalls average in size can reach several tens of cubic meters. The rockfall moves in the form of repeatedly repeating jumps with a speed of sometimes up to 60 m / s, which corresponds to about 200 km / h. Stone blows of approximately 20 cm or more are fatal to humans and cause serious damage to motor vehicles..
Mudflows or mudflows.
Stormy mud or mudstone stream, suddenly occurring in the channels of mountain rivers. The main reasons for the emergence of mudflows are heavy rains, the destruction of the lintels of water bodies, the intense melting of snow and ice, earthquakes and eruptions of volcanoes. The frequency of mudflows in the same areas is different, but most often once every 3-4 years. When mudflow from mountains to the valley along riverbeds and streams in a continuous stream masses of water with mud, stones and twisted tree trunks move at a tremendous speed.
Mudflows can carry individual rock fragments weighing 100-200 tons or more. The leading front of the mudflow wave forms the head of the mudflow, the height of which can reach 25 meters. The length of the channels can be from several tens of meters to tens of kilometers, depth from 1.5 to 15 meters. The mudflow velocity ranges from 2 to 10 m / s. Getting into the mudflow is almost always fatal. This is due to the fact that people, as a rule, are buried under a thick layer of mudstone sediments and cannot be saved because of the difficulty of finding.
Based on materials from the book Encyclopedia of Survival.
Chernysh I. V.