From the point of view of the origin of the cave is divided into natural karst, lava, and artificial mines, mines, mines, quarries, salt mines. The caves are very different. They are horizontal, vertical, inclined and are divided into dry and watered, simple and labyrinth.
Underground caves and labyrinths, their dangers, features of movement and behavior, actions in an emergency or extreme situation.
As a rule, caves, both natural and artificial, attract attention by the opportunity to hide from the weather and predators and discover water. The main danger when examining caves is that it is very easy to get lost in them, even with a small length, because there can be a labyrinth in the cave, dips that are difficult to notice in the floor in poor light, there is a high probability of collapses.
and, importantly, the ability to quickly light an extinct torch, candle or something else.
Walk slowly, constantly illuminating walls, the ceiling and the floor, in order to detect collapses, dips in the cave floor, side branches in time.
If there are branches, be sure to mark the direction to the exit of the cave.
Never try to go either to one branch or another, but to follow the rule of the right hand, that is, to go deep, adhering only to all right moves. Conversely, either all leftists, or (which is preferable) to return in the same way.
Remember that all the inconsistencies in karst caves are fragile and brittle enough, so you can’t use them as a serious support for ascents and descents.
In mines, old wooden fasteners can be rotten and extremely unreliable and can cause the roof to collapse even with a light touch..
In some natural and artificial underground voids, there may be a different gas. In some cases, it extinguishes an open flame, your source of lighting, in others, a specific smell is felt. In both cases, you must immediately leave the cave or mine.
Possible hazards in underground caves and labyrinths.
Fear. Absolute darkness and loneliness are perceived by each person differently. A large number of people have an instinctive fear of the dark, so their aversion to caves can be easily explained. Fear of the night is probably as old as all of humanity. We inherited this feeling from our prehistoric ancestors..
In those distant times at night, man was unarmed in the face of danger and could not repel the attack of wild animals. At night, every noise seems suspicious, disturbing, menacing. Fears conquer a person at night more than during the day. What is all the same scary in the dark? Some are scared to be alone, while others, on the contrary, are afraid that someone has lurked in the darkness. Many in the darkness of caves are afraid of spirits, ghosts, ghosts, devils and sorcerers.
Hallucinations. In addition to the fear that arises in the cave due to loneliness and various superstitions, various optical phenomena, for example hallucinations, visions, also affect the human psyche. This human brain, tired of experiences, does not stand the test of darkness. Sometimes suddenly, in the absolute silence and darkness of the cave, someone’s distant voices begin to be heard, light appears. With such mental disorders, some people have a difficult to explain phenomenon of claustrophobia, or fear of confined space and darkness. A person suffering from claustrophobia begins dizziness, headache, nausea. But for all this to pass, just exit the cave.
Cold. In the northern regions, cold is the main inconvenience and danger for cavers and those who, for one reason or another, got into the cave. As a rule, caves located in the northern regions have a year-round low, often minus, temperature. But in general, the structural features of the caves create a constant average annual temperature of 0 … + 12 degrees in various caves. But there are caves with an average annual temperature above +20 degrees.
Such caves are found on the Kugitang ridge in Turkmenistan. The presence in the caves of both low and high temperatures is aggravated by high (up to 100%) air humidity and a sufficiently high water cut in many underground cavities. In some caves or their separate places, special conditions of air circulation may occur, which is associated with the structure of the underground cavity. Due to the creation of natural wind tunnels with a constant current of cold air and the flow of such air into natural underground bag-shaped depressions, glaciers and snowfields that do not melt throughout the year can form, ice crystalline formations.
Such caves are found in the highlands of the Pamirs, Tibet, and in lower mountainous regions, for example, in the Caucasus, Crimea, Sayan Mountains, as well as in caves of Western Europe and North America. Due to the lack of wind, negative temperatures are kept in such caves all year round, which prevents people from staying in them for a long time. In some cases, even frostbite is possible, especially hands.
Dampness. Dampness is a constant companion of many caves, where high humidity, even at high positive temperatures, with prolonged exposure to the ground, causes first light and then severe chills. Clothing becomes wet and loses its thermal insulation properties. Drying wet, and even more so wet clothes in a cave is almost impossible. Cold and damp, in addition to the main physical effect on the human body (associated with hypothermia), have a strong effect on the psyche. This is manifested in a delayed reaction, apathy, which leads to the adoption of wrong decisions and fatal errors leading to death.
Waterlogged caves are even more dangerous, because in caves of both northern and temperate latitudes, the water is quite cold; its temperature ranges from -5 … + 2 degrees. In many caves, modern streams in the form of underground streams and rivers sometimes completely fill some sections of the galleries (such places are called siphons) or leave a small gap free of water (half-siphon) under the ceiling of the cave. To go through such galleries, cavers have to use scuba gear, which in itself places high demands on technical preparedness.
In caves with vertical wells, when watering them, underground waterfalls are formed, which are a serious obstacle to the advancement of a person, even with special skills and equipment. But the main danger when staying in flooded caves are floods. During the flood, the power of the waterfalls increases significantly and new ones appear, dry galleries are flooded, small streams turn into turbulent rivers. Where a bubbling stream fills the lower parts of the cave passages, new siphons form.
In such a situation, cavers or accidentally wandered into the cave people who were taken aback by the flood there are forced to sit out on the highest parts of the cave. The cause of underground floods are heavy and prolonged rains, which turn out to be the main reason for large amounts of water entering underground voids from a large surface catchment area in a short period of time..
Collapse hazard. Among horizontal and slightly inclined caves, gypsum and salt caves are the most bumpy. To exclude the possibility of a collapse underground, you can not scream (with the exception of places where there is flowing or falling water). In especially dangerous landslides, one must speak in a whisper and move with utmost care. Vertical wells and shafts are dangerous because of the possibility of a rockfall arising from the dumping of stones with a safety rope on the head of people descending or below.
In artificial structures (quarries, catacombs, mine workings and adits), the collapse hazard is much higher than in karst caves, since artificial workings often upset the balance of the rock within the massif. In addition, the supports supporting the ceiling and walls of underground workings rot over time and become unusable, leading to their collapse under the weight of the rock. This is often facilitated not only by natural humidity, but also rain (melt) water seeping through cracks in the rock from the surface or groundwater available in the area.
Gas contamination. In poorly ventilated caves, especially in dead-end pockets, the accumulation of carbon dioxide and methane is possible. These gases are completely odorless, invisible and therefore pose a special danger. Methane is mainly found in artificial underground cavities and at a ratio of 1:10 is explosive. Unlike carbon dioxide, methane is lighter than air and therefore accumulates in especially dangerous dead-end drifts. Carbon dioxide, on the contrary, accumulates in the lower part of the cave passages, and therefore very low passages and manholes, sharp local lowering of the floor of the caves are dangerous.
In karst formations, where obviously there cannot be a high methane content (explosion-proof concentration is 5%), a match can be used to determine its presence. With its increased content, the flame of the match will flare up unnaturally brightly. Conversely, the same match does not burn with a high carbon dioxide content. In both cases, especially in the second, being in a cave is dangerous. Dangerous gas contamination of a cave or man-made development can also be caused artificially. It can be promoted..
A few long time burning candles in a small underground space (grotto) with poor ventilation or if there are several people in it.
Using underground stoves in small premises.
Use for lighting torches of long burning (dipped in fuel oil or kerosene).
Making bonfires in the cave itself or in the artificial mine or at its entrance.
In the latter case, back draft may occur through a natural chimney.
All of the above, except for candles, leads to smoke in the passages and the formation of carbon monoxide. Candles also contribute to the release of carbon monoxide, and, in addition, in a small room, burning candles create a child, which causes a severe headache, and even death can occur from carbon dioxide poisoning.
Based on materials from the book Encyclopedia of Survival.
Chernysh I. V.