Located in Baihe Town, Jilin Province, Changbai Mountain is the most dangerous plateau volcano in mainland China and even In Asia.
600 million years ago, the Changbai Mountain Boundary was just a vast ocean, with the continuous passage of time, the earth has experienced Yanshan, Himalayas and other orogenic movements, the sea gradually receded, the crust of Changbai Mountain is also constantly changing in fracture and lifting, underground magma gushes out along the cracks, which is the first lava spray of the crater of Tianchi in Changbai Mountain.
The history of eruptions of Changbai mountain volcano
In the eruption history of Changbaishan Volcano, the eruptions in 1668 and 1702 were relatively large, and the dust from the volcanic eruption even drifted down to the area of Jingchengfu on the east coast of Korea 150 kilometers away, the thickness of the dust reached 4 centimeters, and the large eruption in 946 AD was considered to be the largest volcanic eruption in the world in 2000 years, when the volcanic debris produced covered the entire area within a radius of 50-70 kilometers of Changbai Mountain. The ash from the eruption drifts eastward all the way to the Sea of Japan, where ash of about 6-10 cm thick can be found in the lake sediments.
According to the Korean "Records of the Lee Dynasty" on the eruption of the Changbai Mountain volcano from 1668 to 1702 AD, at noon in Funing Province, Hamgyong Province, the sky was suddenly dark, sometimes yellow and red, smoke filled, fishy smell, people seem to be in the steaming furnace, like a sauna. This sign slowly subsided after the fourth change, and when viewed from a high place, it was dusty and dark. These texts vividly record the time, color, smell and thickness of volcanic ash, which many volcanologists believe was caused by the eruption of Changbai Mountain Volcano. In the eruption of changbaishan volcano from 1199 to 1200 AD, the Records of the Lee Dynasty also recorded related scenes, for example, in the summer of the second year of the Goryeo Jinjong, the water of the southern well suddenly boiled, and the sound was like the sound of cattle, and it lasted for more than ten days. At the end of the winter, there was a roar of thunder, and occasionally a black gas emanated from the Crane Ridge, which immediately filled the whole of Kyoto.
There are two forms of volcanic eruptions, one is naturally occurring and the other is man-made. The former eruptions are equivalent to Icelandic eruptions, and the latter erupt more intensely than Icelandic eruptions. At the time of North Korea's third underground nuclear explosion, the frequency of earthquakes in the area around Changbai Mountain increased, most notably a few seconds after the explosion, and there was a magnitude 5 earthquake of about 5 in the northwest region about 20 kilometers from the North Korean nuclear explosion area, that is, near Tianchi in Changbai Mountain. Some volcanic eruption research experts believe that if the magnitude of the nuclear explosion exceeds 6, it may stimulate or brew the danger of eruption of Changbai Mountain Volcano.
As an active volcano, Changbai Mountain, like other active volcanoes, is in danger of erupting magma at any time. Zhang Hengrong and other experts in the Changbai Mountain area laid out gps mobile observation network shows that the crust of Changbai Mountain is in a state of expansion and rise, there is a significant low-speed layer 10 km underground near the crater, it is speculated that there may be a magma chamber, which is in danger of volcanic eruption. Relevant experts represented by Liu Ruoxin believe that although Changbaishan Volcano is an active volcano, it does not show signs of recent eruptions. This view is similar to the views of Guo Lucan and Wang Yansheng, who believe that the current Changbaishan volcano is in the process of transformation from middle age to old age, and the distribution law of parasitic volcanic piles in the area shows that a long process of energy accumulation is required for volcanic eruptions, and the fault structure of Changbai Mountain does not have the conditions for energy aggregation.
Changbai Mountain Volcano Detection Station
Changbai Mountain Volcano Detection Station as the main detection department of Changbai Mountain Volcano, has a history of more than 20 years, through more than 20 years of volcanic detection, the detection station experts have observed the magma room disturbance phenomenon of Changbai Mountain volcanic activity in 2002 and 2005, that is, during this period, the volcanic seismic activity increased by nearly two amounts, and in the process of volcanic deformation detection, it is also true that the phenomenon of uplift of Changbai Mountain has been observed, which reflects the change of mantle source materials there are also some index lines of increase. It can be seen that there is indeed an active magmatic system under the Changbai Mountain.
Generally speaking, the recurrence law of large-scale eruptions is measured in 10,000 years, while small- and medium-scale eruptions are measured in the millennium, and through the magma room disturbance phenomenon in 2002 and 2005, the high probability shows that the current Changbai mountain volcano is in the replenishment stage, which is somewhat different from the prediction of the Changbai Mountain predicted by the Japanese professor or the eruption within 10 years. Of course, the exploration of volcanic eruptions has no borders, whether there will be volcanic eruptions in the past ten years, enhancing the survey strength of Changbai mountain volcanoes and minimizing the scope of volcanic eruptions are important links that the volcanic survey team needs to pay attention to.
Hazards of volcanic eruptions in Changbai Mountain
The profound effects of volcanic eruptions have always been a headache, and they will produce harmful gases such as sulfur dioxide, hydrogen sulfide, carbon dioxide and hydrogen chloride during the eruption process, which can not only sink the soil to erode crops, but also rise to the Earth's atmosphere, under the guidance of the wind direction, spread to other boundaries, causing a wide range of gas pollution problems. When the sulfur dioxide concentration reaches 6-12 PPM, it will have the most direct impact on the nose and throat, when the concentration reaches 20 PPM, it will cause discomfort to the eyes, and when the concentration reaches 10000 PPM, it will instantly sting the skin, which can lead to death in severe cases.
Second, volcanic ash is also severely affected. Due to the small mass of volcanic eruption fragments, in addition to vertical scattering, most of the volcanic ash will be emitted to the periphery of the crater, the scope of the impact is very wide, the accumulated depth is thick, can crush houses, branches and communication cables, causing great economic losses. Secondly, a large amount of volcanic ash will also cause residents to have difficulty breathing, skin allergies and other symptoms, reducing people's quality of life and endangering human life safety.
Toxic gases and dust from volcanic eruptions in Changbai Mountain
Today's Changbai Mountain around the dense population, tourism is developed, in the Tianchi Mountain volcanic eruption after the scope of the prediction, Li Jitai and other experts believe that if the Tianchi Mountain volcano erupts, its lava flow process will produce nearly 100 meters of continuous explosions, this explosion will increase the scope and extent of the disaster.
Secondly, Fengman Reservoir is located in the southeast of Fengman District, Jilin City, with a basin area of 4250km2, about 200km upstream of Fengman Hydropower Station, there is a Baishan Hydropower Station, which controls a basin area of 1900km2, while at 38km of Baishan Hydropower Station is Hongshi Hydropower Station, and its control basin is 2030km2. According to Liu Junqing's dam failure model combined with the hydrodynamic formula and the characteristic analysis of the local geological structure, when the magma erupted in Chishan on the same day and half of the reservoir capacity was discharged from Tianchi, the flow of the Erdaobai River, which is 50KM away from the crater, will be greater than the peak of the Three Gorges flood of the Yangtze River, which will pose a devastating threat to the Baishan Hydropower Station 280km away from the crater.
In the risk assessment of the Changbai Mountain volcanic disaster, the affected areas included nine major areas, including Baishan City, Jingyu County, Fusong County and Changbai Korean Autonomous County, with a population of nearly 1.35 million, and its economic losses and agricultural industry destruction are difficult to count.
From the above views and conclusions, it can be seen that the harm of the eruption of Changbai mountain volcano is very extensive, especially in the continuous development of the economy and society, once the volcano erupts, the number of people, economic property and crops affected will be an unprecedented huge data. This requires relevant volcanic eruption researchers to strengthen the detection of volcanoes in the process of volcanic detection, do not let go of the slightest sign of volcanic activity, and make relevant preventive measures in the first time, always pay attention to and care about the safety of people's lives and property, and cultivate their subconscious sense of trust in science while supervising the people's attention to life.
bibliography:
[1] Changbai Mountain Tianchi Volcano - a modern volcano with potential eruption risks_Liu Ruoxin Chinese Journal of Geophysics CNKI 1992-10-27
[2] Study on the age of the latest major eruption of Tianchi Volcano in Changbai Mountain and its significance_Liu Ruoxin Science of China (Series D: Earth Sciences) CNKI 1997-10-15
[3] Research on disaster risk management of Tianchi Volcano in Changbai Mountain_Wang Qian, Ocean University of China CNKI 2014-05-20
[4] Research progress of Changbai Mountain volcano Liu Jiaqi Mineralogy, Petrology and Geochemistry Bulletin CNKI 2015-07-10
[5] Disaster risk assessment and emergency management countermeasures of Changbai Mountain Volcano based on the largest eruption in history_Gong Wenting Northeast Normal University CNKI 2009-05-01
Author: Worry-free Review: Yamakawa Proofreader: Plum