The Current Oxygen and Hydrogen Isotopic Status of Lake Baikal

This study revises the delta O-18 and delta H-2 status of Lake Baikal. The mean values of delta O-18 and delta H-2 varied from -15.9 to -15.5 parts per thousand and from -123.2 to 122.2 parts per thousand, respectively, for the past 30 yr. The isotopic composition of the lake remained more ''light compared to the regional precipitation and rivers inflows. The isotopic composition of the lake has begun to change since ca.1920 after the Little Ice Age; however, Lake Baikal still has not reached the isotopically steady state in the present. The calculated composition of the steady-state should be -12.3 parts per thousand for delta O-18 and -103.6 parts per thousand for delta H-2. If regional climate parameters do not change dramatically, Lake Baikal will reach these values in ca. 226 yr. Based on isotopic fingerprints of the upper (0 to 150 m) and near-bottom layers (ca. 150 m from the bottom floor), the renewal in the southern and central basins of Lake Baikal has occurred recently compared to the northern Baikal basin, and the size of the mixing-cell of downwelling is close to 30 km.

Automated summary

This study revised the delta O-18 and delta H-2 status of Lake Baikal, finding that the lake's isotopic composition is lighter compared to regional precipitation and river inflows. The isotopic composition of the lake has begun to change since 1920, and it is expected to reach a steady state in approximately 226 years.