EQUILIBRIUM-LINE ALTITUDES ON RECONSTRUCTED LGM GLACIERS OF THE NORTHWEST BARGUZINSKY RIDGE, NORTHERN BAIKAL, RUSSIA

Abstract

The spatial extent of the Last Glacial Maximum (LGM) glaciers (MIS 2) in the northwest of the Barguzinsky Ridge has previously been mapped. Geographical information system (GIS)-computing of the glaciers' quantitative parameters allowed us to use various methods to evaluate the former equilibrium-line altitudes (ELAs) for the 10 largest glaciers. ELAs on reconstructed glaciers were calculated using four common methods: (1) the median elevation of glaciers (MEG), (2) the toe-to-headwall altitude ratio (THAR), (3) the accumulation area ratio (AAR), and (4) Gefer's method. The results suggest that the mean macroclimatic LGM “background” ELA for the area studied was about 1200±145 m above present sea level and the mean ELA depression relative to modern conditions was about 1100 m. Tentative estimates suggest that the reconstructed glaciers could have existed in a drier (about 1.5 times drier-than-present) environment if the mean summer air temperature was about 8–9 °C lower than present day.