Changes in Hailuogou Glacier during the Recent 100 Years under Global Warming

Large changes,associated with global warming,have occurred at the Hailuogou Glacier,Mt Gongga,China,since the early 20th century.The terminal altitude of Hailuogou Glacier has retreated 300 m since 1 823 with an average retreat rate of 1.64 m·yr-1,and what is more,the retreat has accelerated since the 20th century.Various data indicate that,during the last century,the glacier retreated 1 821 m in the past 76 years,with an annual mean retreat rate of 24 m.The variation of mass balance in Hailuogou Glacier has been reconstructed by means of hydrological and glaciological methods.Mass balance records over the last 45 years show that the glacier has suffered a constant mass loss.The cumulative mass balance,10.83 m water equivalent,indicates a mean mass loss of-0.24 m water equivalent per year.The ablation period has lengthened and the ablation area has become larger in the glacier.As the climate has become warmer,the equilibrium line has risen and,since the 1980s,change in the glacier's surface morphology has occurred.The change includes decrease of glacier thickness,enlargement of glacial caves and lakes,increase of surface runoff,cave-in in the big ice-fall,wide distribution of crevasse and reduction in the size of seracs.The crucial cause of the changes of the glacier's surface morphology is heavy ablation on the ice surface and meltwater eroding the inner glacier.In a world,the Hailuogou Glacier has suffered a rapid loss of mass as a consequence of climate warming.