New Data on Deuterium Excess Values of Glacial Ice in Kamchatka Peninsula

The isotopic signature (δ¹⁸О, δ²Н, d-excess) of the glacier ice in Ushkovskii volcano (Kamchatka Peninsula) was studied. A new shallow ice core was obtained in 2022 in the Gorshkov crater. The 14 m long ice core was dated by counting the annual layers, which were also compared with known eruptions in recent years. The upper 14 m of the glacier were formed over the last 16 years (from 2006 to 2022). The values of δ¹⁸О vary from −16 to −24‰, and the values of δ²Н, from −110.5 to −177.7‰, while the mean values are −20.5 and −150.2‰, respectively. The d-excess values vary with depth from 8.7 to 21.3‰ at a mean value of 13.7‰. For winter horizons at low values of δ¹⁸О and δ²Н, an increase in d-excess is noted. Such features are associated with the origin of moisture brought to Kamchatka. The source of moisture is the Pacific Ocean, the Sea of Okhotsk, and the Sea of Japan, for which there are pronounced differences in the conditions of moisture evaporation between summer and winter. The trends of increases in the δ¹⁸О and δ²Н values from 2006 to 2022 are accompanied by a decrease in the deuterium excess, indicating an increase in summer precipitation. However, in addition to changes in the seasonal proportions of precipitation, the d-excess values of ice may reflect climatic changes in the source of moisture.