Baikal during a single century fascinates many people. But few know about the secrets that keeps the lake. These secrets, many researchers have tried to study, but over time they became more and more.
One hundred and fifty years ago, Lake Baikal earthquake of 9 points. As a result, a huge piece of land to the right of the Selenga River delta was under water. At this place there was failure of the bay. Under water with the land left several villages. It was the biggest in the historical period in Baikal earthquake. Now scientists say that this disaster will soon be repeated.
Baikal rift is currently continuing to form, this is manifested in a stretching of the crust and seismic activity. Baikal shore each year at a rate of 5 mm apart. Based on this fact, there was a hypothesis that the Baikal rift in a million years would split the Eurasian continent.
On Baikal frequent earthquakes, seismographs recorded during the year to eight thousand of seismic events. Their epicenter was at a depth of 13 — 22 kilometers. Most of them are very weak, but in the Baikal region and earthquakes occur. Speaking of Baikal earthquakes, usually remember Tsaganskoe earthquake, which led to the formation of the Gulf of failure — one of the largest bays of Lake Baikal. We can say that this earthquake was a warning, a lesson.
In eastern Siberia, it was the first seismic event. The consequences of this earthquake have been studied for quite a high scientific level. According to details, which were contained in the reports and further publications were identified epicenter and intensity of tremors. The earthquake occurred on January 11, but the first tremors were also observed on January 10 evening. A January 12 followed by even more strong aftershocks. As a result of cracks in the ice of Lake Baikal, and the water were 357 wooden yurts and 310 houses. Was flooded meadow and a large amount of arable land, killed a lot of livestock. Because the water is coming gradually, people had time to escape. At intervals of a day, there were two strong aftershocks. In "Irkutsk Chronicle" says that in all the churches bells themselves, all of the buildings in the city cracked and swayed, and people were not able to stand up. In the land of the gap formed, and from them came the water with silt.
The shaking was so strong that the Baikal break the ice, creating a tsunami. Beach ridge and the area faced a wave Tsaganskoy steppes, an area of 230km2, was the bottom of Lake Baikal. As a result, homeless, livestock and household goods were 1,300. Lasted more than a year damped shocks soil. This catastrophic earthquake has turned to people and poor socio-economic consequences. They had to adapt to the changing conditions of water use and land use.
Such earthquakes, which are accompanied by the lowering of the Baikal bottom and land areas are not uncommon. So srednebaykalskoe earthquake, which occurred in 1959, it was the intensity of 9 points and had the epicenter in Lake Baikal. As a result, the bottom of the lake dropped by 20 meters near the epicenter. It is even considered that litter Cherkalovo bays and Ambassadorial rubbish generated by the introduction of such earthquakes.
Traces of catastrophic earthquakes still keep the shore of Lake Baikal. They achieved by 12 points. They show how a high degree of optimism of modern seismic zoning. It also is not just confirmed the harsh reality. For example, Muya earthquake in 10 points occurred in an area deemed almost aseismic. In the seven-point Baikal earthquakes happen on average every 1-2 years, vosmibalnye — every 5 — 10 years, a nine — every 50 — 100 years. And once in 150-200 years are disastrous earthquake which force reaches 10 or more points.
Scientists, seismologists around the world have long preoccupied with finding technologies that could predict earthquakes, at least two days before the crash. During the last earthquake occurred, the scientists from the Irkutsk Institute of the Earth's crust had supervision over the content of the natural gas in the water of Lake Baikal. They received the first confirmation of his theory, but it has not yet verified statistics. The scientists found that in water for some time before the earthquake there is a sharp increase in the helium content. Although usually helium dissolved in the bottom rocks.
The importance of short-term forecast. If researchers can develop a sufficiently accurate method, it will be possible to organize the timely evacuation of the population and prevent the loss of life. But some question the need for such a method, arguing that it would be impossible to avoid panic in any way and prevent the destruction of the buildings will also be impossible, even knowing the date and time of the earthquake.
Some seismologists have argued that much more damage can cause panic than the strongest earthquake in the Baikal region. But no one disputes the fact that the need to develop and test methods of short-term earthquake prediction. While no one really can not calculate and predict earthquakes. There are many earthquake precursors — geophysical, seismological, hydrological. The problem is that before the earthquake, these precursors do not work together. Some of them point to the fact that the preparation of an earthquake is, and the other did not specify. It turns out that these symptoms before the earthquake occur haphazardly.
Irkutsk scientists as the basis of studies have geochemical precursors, which are based on the change before the earthquake content of various gases in groundwater. Even during the Tashkent earthquake was recorded this effect, it was in 1966. There scientists were followed for ten years, and noted that the radon content in water increased sharply just before the tremors. Then it is considered a scientific discovery, but over time it was noticed that this effect is not always confirmed by other earthquakes. Radon sometimes increase after the disaster, and sometimes not increase at all.
Irkutsk scientists took the idea for the foundation and began to look over the content of helium in the Baikal and Angara water. This gas was chosen randomly. At that time, scientists have been a device for measuring the helium content, besides the gas is very common in the waters of Baikal region. Last four years, scientists are constantly sampling. During these four years have been only minor fluctuations of helium. During this time several small earthquakes, but to link this with the vibration of the helium content was not possible. This is explained by the fact that these earthquakes occurred in remote locations. But in August, there was a strong earthquake in the area where the observations were made. Scientists noted that a couple of days before the earthquake in the water content of helium fell sharply and remained until the day of the disaster to a minimum. And on this day for a couple of hours before the tremors began to rise dramatically increase the helium content. At the time of the first earthquake, it reached the peak.
This effect is easily explained — water crustal faults are exposed to high helium content.
Are continuing surveillance, and if the effect is repeated in other earthquakes, this technique can serve short-term precursors.
Category: Scientists, experts, science