Overall, glaciers in the Greater Himalayan region that have been studied are retreating an average of between annually. The only region in the Greater Himalaya that has seen glacial advances is in the Karakoram Range and only in the highest elevation glaciers, but this has been attributed possibly increased precipitation as well as to the correlating glacial surges, where the glacier tongue advances due to pressure build up from snow and ice accumulation further up the glacier. Between the years 1997 and 2001, long Biafo Glacier thickened mid-glacier, however it did not advance.