Scientists have analyzed the materials from the third season of the complex expedition "Eastern Bastion – the Kuril Ridge", clarified various data and, based on the work done, put forward a number of proposals for the economic development of the region.
When force majeure is almost the norm
From August 11 to September 18, 2022, scientists, military personnel, and volunteers, based on the results of past expeditions, continued to study the islands of Iturup, Urup, Chirpoy, and began exploring the island of Kunashir.
According to Anatoly Kalemberg, head of the “Eastern Bastion – the Kuril Ridge” expedition, specialist of the Expedition Center of the Ministry of Defense of the Russian Federation, the 2022 season was the most difficult in terms of climate conditions in all the time of the expeditions: changeable and unpredictable weather, violent storms, heavy rains, squally wind.
“We were often forced to take refuge in bays, and those who stayed in tent camps felt the full insidiousness of the Kuril weather,” says Anatoly Kalemberg. “On an expedition, I get more force majeure situations in a day than at home in a year. These are the Kuriles. Here a lot depends on the luck and experience of navigators, boatmasters. The landing and loading on the ship in Medvezhya Bay, on the Pacific side of Iturup, was very difficult . A rolling wave – it looked like we were moving, everything was fine, suddenly a wave threw the scow to the side, and it was already sitting on the rocks. And it was very difficult to get it off: it is heavy, the wave kept hitting, there was a high risk of getting a hole and sinking the ship. But everything worked out. The people and cargo (tents, kitchen equipment, food) had to be transported on a small rubber boat, which took quite a long time. We were very lucky on Chirpoy. Few people managed to land on it from the Sea of Okhotsk, but we did it. The scientists got a full day of work on the island."
The work of the researchers was complicated by the remoteness of the islands from the places of civilization. Chirpoy and Urup are uninhabited (there are only three lighthouses on Urup), there is no one to turn to for help, you have to to rely only on yourself. Therefore, the key to the successful conduct of the expedition is high-quality equipment, carefully prepared logistical support, and strict compliance with security measures by all the expedition members.
Tsunami from thousands of years ago
Earthquakes on the Kuril Islands also occurred in ancient times, sometimes reaching 10 points and accompanied by a tsunami. Scientists have come to this conclusion. How do they know that? Studying the relief, you can see traces of seismic processes. They have been observed in bedrock and quaternary sediments mainly in the coastal zone.
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The expedition participants determined the intensity of the earthquakes, identified and mapped their epicenters. Signs of 8-10-point earthquakes on Iturup were found in Kuibyshev Bay, in Kasatka Bay. Traces of erosion in the latter indicate the periodic penetration of a tsunami deep into the land.
Mikhail Kuznetsov, a junior researcher at the Department of Geomorphology and Paleography of Moscow State University, comparing old maps with satellite images, determined how the position of the coastline changes over the years. During the expedition, Mikhail studied the relief of the coasts, their geological structure, the processes occurring on them, took samples for granulometric analysis and mineralogical analysis for the detailed identification of the modern dynamics of the coasts. In particular, based on the results of the sample analysis, the scientist concluded that the islands could be used for economic purposes.
“To develop Urup, it is advisable to conduct economic activity on the Okhotsk side of it, where tsunamis are much less frequent, their height is lower, and they are less destructive than the ones from the side of the Pacific Ocean,” Mikhail Kuznetsov believes.
According to his conclusions, most of the shores of Urup are unsuitable for economic development, except for two bays. One of them, Novokurilskaya, is the safest for development. There is a convenient landing place in the bay, and its shores are the most stable. The buildings can be placed on a 30-40-meter terraced level, not subject to storms or tsunami splash. By the way, on the eastern shore of Novokurilskaya Bay, there are still remnants of Japanese mooring structures.
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The second place is the central part of the island, the Otkryty roadstead, Tokotan Bay, where there is a small area, also, according to Mikhail Kuznetsov, suitable for development. The bay consists of two bays. In its southern half is the mouth of the Tokotan River. If a tsunami suddenly occurs in front of this place (and it will definitely happen sooner or later), its splash deep into the territory will be very large: due to the rather flat land relief, the wave will not meet any resistance, and up to 3km along the basin of Lake Tokotan will be flooded. Similar events have already happened there. Usually the coast is a self-regulating system, that is, it seeks to protect itself. When the coast is washed away and has not recovered over time, this indicates that catastrophic phenomena occurred in this place. In the northern part of the Otkryty roadstead, on the eastern flank of the bay, the impact of a tsunami is possible only directly in the coastal strip. Above it there are terraces with flat relief, on which you can build permanent structures if you erect coastal fortifications.
The researchers also revealed the supposed consequences of the strong Simushir earthquake of 2006 (magnitude 8.3) in the area of the Middle Kuriles on Urup.
According to Mikhail Kuznetsov, on the Pacific side of the Castricum Peninsula, driftwood was found – tree trunks, large branches brought from somewhere and washed ashore. An ordinary storm would not be able to throw such massive logs 100m from the shore. This height of the splash, about 7m (the maximum height to which a wave reaches), can only be reached by a tsunami, which brought these trunks up. Usually, the so-called slope undercuts speak about tsunami impacts on the shore, when turf is torn off the coastal slope, rocks and sediments are exposed. During the expedition of 2021, these traces were found on the Pacific side of the Castricum Peninsula. In 2022, much fewer such traces were found on the Okhotsk Sea side of Urup, and it is not always possible to unequivocally predict their tsunamigenic nature.
Chirpoy is the youngest (volcanically and seismically, as well as from the point of view of dangerous geomorphological processes) dynamic island visited by the scientists. It consists of three merged volcanoes, the eruption of which occurs quite often. Its shores are bare, frozen lava flows that flowed into the Sea of Okhotsk or the Pacific Ocean. Traces of volcanic mudflows, lahars, are visible everywhere.
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“The Kuril Islands are a paradise for scientists. They are if not a white, then definitely gray spot on the world map,” Mikhail Kuznetsov believes. “Once you get there, you are taken captive by the elements. All plans are constantly changing, and it is impossible to predict which of the planned work will be completed. When we landed on Chirpoy and divided into three groups, a squall wind suddenly came, a thick fog descended. The island is small, but when you come to the surface of the lava flow, with visibility of only a few meters, it is very easy to get lost. There are no landmarks, you walk on lava blocks, the terrain is very difficult, sharp stones everywhere. We walked around the island from several sides, from one of them there was a clear smell of hydrogen sulfide, and fumaroles (vents from where volcanic gas comes out) were visible along the shores. The development of Chirpoy is out of the question, because it is a "gunpowder barrel": everything built will quickly be destroyed by a possible eruption, earthquake, mudslides (lahars), landslides, scree and washed away by a tsunami."
The researchers propose to declare a part of the coast of Shchukin Bay to the north from Cape Klyuchevoy to Cape Neproidesh on Urup geomorphological monument.
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“The Kuril Islands are a precious necklace given to humanity by nature,” adds Mikhail Kuznetsov. “Once on the mainland, you feel restless for a long time, and you want to go back. Probably, this happens because only at the edge of the world do we begin to clearly realize, or maybe ‘remember’ that we are part of nature, as our ancestors were, only closed off from it in cities. As a result, you begin to feel yourself in a new way and look at the world in a different way.”
The Russian Geographical Society, together with the Ministry of Defense of the Russian Federation, continues to study the Kuril Islands. The studies began in 2019. The 2022 expedition was attended by 75 people who passed the competitive selection of the RGS, including volunteers with disabilities.
Marina Kruglyakova