Vasil'chuk Y.K., Ginzburg A.P., Tokarev I.V., Budantseva N.A., Vasil'chuk A.C., Palamarchuk V.A., Vasil'chuk J.Y., Bludushkina L.B., Slyshkina E.S. —
Stable isotopes of oxygen and hydrogen in frost blisters of the Chara River valley, Transbaikalia
// Arctic and Antarctica. – 2024. – น 2.
– P. 90 - 129.
DOI: 10.7256/2453-8922.2024.2.70706
URL: https://en.e-notabene.ru/arctic/article_70706.html
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Abstract: The study's focus is on the distribution of oxygen and hydrogen isotopes in the ice cores of frost blisters in the Chara River valley, Transbaikalia. The Kodar and Udokan mountain ranges surround the Chara Depression. Cryogenic (frosty) heaving is common in high humidity areas with loamy, clay, and peaty sediments. In summer 2023, the authors described two seasonal frost blisters in swampy, forested depressions on the periphery of the Charsky Sands (in the so-called thermosuffusion funnels). Oxygen and hydrogen isotopic compositions of oxygen (δ18O) and hydrogen (δ2H) in blister ice were analyzed. It has been established that seasonal frost blisters are formed mainly due to downward freezing of the water-saturated active layer sediments, but in some cases, ice was formed as well due to upward freezing from the lower boundary of the active layer. The vertical distribution of the isotope values, as well as the δ2H-δ18O ratio in ice, indicates a relatively rapid freezing of water in closed system conditions during one cycle of freezing. In the ice layers sampled horizontally, very similar isotopic composition values were obtained (for example, in blister ice 1, δ18ฮ values ranged from 17.51 to 17.32), which indicates consistent horizontal freezing of ice layers. The slopes of the δ2H-δ18ฮ ratio lines for blister ice are 5.82 (blister ice 1) and 5.95 (blister ice 2). A decrease of the δ2H and δ18ฮ values of blister ice on frost mounds with depth and a slope of the δ2H-δ18O ratio line less than 87.3 indicates water freezing under closed system conditions during one cycle without moisture inflow. The distribution of isotopic values in the blister ice of seasonal frost mound 2 may indicate simultaneous bilateral freezing of the water volume.
Vasil'chuk Y.K., Ginzburg A.P., Tokarev I.V., Budantseva N.A., Vasil'chuk A.C., Palamarchuk V.A., Bludushkina L.B., Slyshkina E.S. —
Morphology of the Buluus, Ulakhan-Taryn aufeis, conditions of its occurrence and stable oxygen and hydrogen isotope variations in the lower part
// Arctic and Antarctica. – 2024. – น 1.
– P. 34 - 61.
DOI: 10.7256/2453-8922.2024.1.70079
URL: https://en.e-notabene.ru/arctic/article_70079.html
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Abstract: Aufeis is one of the most dangerous natural phenomena. The negative impact of aufeis is determined by the unexpected flooding of the territory and subsequent freezing of water, the formation of ice barriers, the icing of underground structures and communications (mines, tunnels, culverts, and sewer wells), as well as the icing of roads and railways, coastal hydraulic structures, etc. There are cases when explosions of aufeis mounds produce catastrophic disturbances within a few seconds. The aufeis that forms annually in the valley of the Buluus Creek is one of the most famous and studied aufeis of Central Yakutia. The aufeis was sampled from a vertical section. The aufeis is layered, and the thickness of the layers is 3-10 cm. In the upper part of the aufeis, the ice layers are thicker than in the lower.
Sampling from the aufeis ice was carried out using a 5.1-cm-diameter steel crown driven by a Bosch electric drill. Measurements of the isotopic composition of oxygen and hydrogen in ice were performed using a Picarro L 2130-i laser isotope analyzer. The isotopic composition of the Buluus ice varies in a narrow range: δ18O values vary from −20.2 to −21.9, δ2H values vary from −159.5 to −173.7. Generally, the ice is isotopically slightly enriched compared to the surface water of the Ulakhan-Taryn creek, where the δ18O value is −22.18 and the δ2H value is −175.1%. Groundwater is isotopically close to the creek water; its isotope composition is also isotopically enriched compared to the ice of the aufeis, with δ18O values varying from −22.17 to −22.25 and δ2H values varying from −173.7 to −175.1.