Changes of the Hailuogou glacier, Mt. Gongga, China, against the background of climate change during the Holocene

摘要

Large changes have occurred at Hailuogou glacier, Mt. Gongga, China, during the Holocene. Various data indicate that it retreated by >1.88 km during the 20th century, and mass balance records show that it suffered a sustained mass loss of snow and ice in the period 1959/60-2003/04, with an accumulated mass balance of -10.83 m water equivalent. Hydrological data demonstrate that runoff from the glacier has been increasing both seasonally and annually, the principal cause being an increase of ice and snow melt water. As the mean temperature in the Hailuogou basin rose by 0.1 ℃ between 1994 and 2004, the runoff increased by 2.6 m~3 s~(-1). Changes of glacier morphology which occurred during this period include a decrease of thickness, enlargement of glacial caves, and reduction of the size of seracs. The Hailuogou glacier advanced three times during the Little Ice Age in response to three cold periods in the Mt. Hengduan region. There also were three noticeable advances in the Neoglacial. There was a very clear relationship between glacier change, climate change and forest line change in the period 3000 a BP-100 a BP. Overall, it is clear that changes of the Hailuogou glacier in the Holocene have been responded to climatic fluctuations, but quantitative evaluation of the relationship is difficult owing to the sparse spatial coverage of reliable evidence and the limited available longer term data.