Scientists of the Siberian and Far Eastern Branch of the Russian Academy of Sciences conducted a ground inspection of a landslide that blocked the Bureya riverbed in the Khabarovsk Territory. Recall that two fishermen saw a change in relief near the village of Chekunda and decided that it was caused by the fall of a meteorite. The landslide blocked the replenishment of the reservoir of the Bureyskaya hydro-electric power station and there was a danger of flooding of the surrounding areas.
A group of the Ministry of Emergency Situations and engineering troops of the Far Eastern District of 200 people were sent to the landslide in order to eliminate the consequences of the natural anomaly. They began clearing of the river bed, and carried out an explosion of the collapsed rock on January 22. An emergency situation was introduced on the territory of the Khabarovsk Territory and in the Bureysky District of the Amur Region. Rescuers make sure that the locals do not go on the ice of the Bureya River.
At the same time, the landslide area was explored twice by geologists, geomorphologists and hydrologists, together with specialists from the Ministry of Emergency Situations. The survey took place in difficult conditions at low temperatures (38 - 40 degrees Celsius below zero). The research team was based in the Chekunda village located 73 km above the landslide, and went to the work place by the car on the ice road, and also they went by helicopter. The fact of the formation of a large-scale "ice tsunami" in the reservoir section with a length of about 25 km was confirmed. Ice of 20–25 cm thick turned out to be completely cracked and washed up on the shore partially. The water depth of the reservoir is 65–70 m with a channel width of 400–500 m.
According to information obtained from the Deputy Director of the Institute for Water and Environmental Problems of the Far Eastern Branch of the Russian Academy of Sciences Alexei Makhinov, the height of water and ice was 15 to 40 m and led to the complete destruction of plant and part of the soil cover around the landslide.
"The occurrence of such a significant tsunami generated by the rockfall is a rare event in Russia. However, on a global scale, such phenomena occur quite regularly”, said Vyacheslav Gusyakov, head of the laboratory for mathematical modeling of tsunami waves at the Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences, member of the Novosibirsk branch of the RGS. - , five such cases have been recorded in the tsunami catalog in the past two decades alone: Greenland (2000, splash height — 50 m), Ausen Fjord, Chile (2004, 60 m), Chehalis Lake, Canada (2007, 38 m ), Icy Bay, Alaska (2015, 190 m), Greenland (2017, 90 m)".
Vyacheslav Gusyakov noted that there was damage to the forest and soil cover along the banks of the Bureya as a result of the occurrence of a water wave. The coastal forest based on larch and birch in this area was uprooted. Only remnants of split stubs were preserved from large trees. Along the boundaries of the splash remained heaps of fallen trees and pieces of ice. Numerous gully and erosion of the soil formed with the return flow of water from the steep slopes.
"All these effects fit perfectly into the overall picture of the impact of tsunamis on the coast, that is recorded during field expedition surveys of the effects of tsunamis in various areas of the coast of the oceans", said Vyacheslav Gusyakov.
Currently, the Bureya water level drop is about 5 m in the landslide area. Level is increasing from the upper part by about 5 cm per day. The level goes down by 1–2 cm per day from the lower part, as a result of the drawdown of water from the reservoir. Another expeditionary survey is planned after blasting and stabilization of the hydrological situation in this section of the Bureyskoye reservoir. This may take place in February or in March. However, a full study of the effects of a landslide and the impact of the tsunami-like wave generated by it on the shores of the reservoir will be possible only in the first half of June, after the end of the spring flood and the disappearance of the ice cover.
Press Service of the Novosibirsk Regional Branch of the Russian Geographical Society