LAUSR

Abstract Glaciers on the Tibetan Plateau are an important freshwater resource for large populations in south and southeast Asia. Therefore, it is important to understand past variations in glacier activity in the region to assess their possible response to ongoing climatic warming. Here, we present the results of analyses of grain size, total organic carbon, pollen ratio (Artemisia to Chenopodiaceae) and the element content of a 435 cm-long sediment core from proglacial lake Buruo Co on the northern Tibetan Plateau. Our results indicate that the Buruo Co catchment experienced relatively warm and humid conditions during 5.2–4.0 cal kyr BP, during which retreating glaciers released large amounts of freshwater. Precipitation was also abundant during this interval as a result of the relatively strong Indian Summer Monsoon and weaker Westerlies and thus the lake level was high. During 4.0–1.3 cal kyr BP, the Westerlies were gradually enhanced and the climate became colder and drier; in response, the glaciers advanced and the lake level decreased. During 1.3–0 cal kyr BP, under relatively cold conditions, a large volume of glacial ice was maintained; nevertheless, under the Westerlies influence, the lake level rose. Four episodes of glacial advance are detected: at 3.6–3.4, 3.2–2.3, 1.9–1.7 and 0.4–0.1 cal kyr BP. These episodes correspond well with Bond events in the North Atlantic, implying that climate change and glacial activity at Buruo Co were largely driven by variations in Northern Hemisphere insolation and by climatic oscillations in the North Atlantic region, via the influence of the Westerlies.