Late Holocene monsoonal temperate glacier fluctuations on the Tibetan Plateau

Abstract

We established a chronology of monsoonal temperate glacier fluctuations in China during the last two millennia based on radiocarbon ages of fossil wood buried in moraines, lichen-dated moraines and tree ring evidence. The chronology includes data from 16 glaciers in the southeastern Tibetan Plateau including the Hengduan Mountains, the central and eastern parts of the Himalaya Mountains, and the eastern Nyainqentanglha Range. Three main periods of glacier advances are identified: around 200–600 AD, 800–1150 AD, and 1400–1920 AD. The glacier advance at about 400–600 AD was the most widespread advance in the southeastern Tibetan Plateau. Basically synchronous glacier advances occurred in the southern Himalayan Mountains during 380–600 AD, 870–1100 AD, 1400–1430 AD and 1550–1850 AD. The glacier advance around 1000 AD also occurred in the central Himalayas. Temperatures in the southeastern Tibetan Plateau calculated from Equilibrium Line Altitude (ELA) depression were 1.0 °C, 0.7 °C, 0.4 °C and 0.1 °C lower than at present (1989 AD) during the periods of 200–600 AD, 800–1150 AD, 1400–1650 AD, and the 19th century, respectively. On a centennial timescale, temperature changes rather than precipitation changes caused by variations of the south Asian summer monsoon are the controlling factor for glacier fluctuations. The widespread glacier advance during the 19th century was probably partly attributable to the result of increased winter snowfall in the central Himalayas.