The glaciers are melting at increasing rates, with rapid deglaciation underway during the late 20th century at a rate that is comparable to or exceeds that of postglacial retreat rates. Between 1980 and 2010, the ice cap shrank at a rate of with a loss of 30% of its area between 1979 and 2014. Between 1990 and 2009, a southeastern branch of the ice cap disappeared altogether. At the northwestern and southeastern ends of the ice cap, the retreat has reached the plateau that Quelccaya sits on. Additionally, parts of the northwestern ice cap have separated from the main ice body and by 2011 the retreat had reduced Quelccaya to a size smaller than at any other time in the past 6,000years. There is some variation between retreat rates measured by different researchers as the Quelccaya ice cap is differently defined and due to differences between extents measured in seasons with and without snow cover. True fluctuations also occur, such as an advance of part of Quelccaya's southern margin reported in 1977 which bulldozed peat deposits, a pause of the Qori Kalis glacier between 1991 and 1993 probably linked with the global cooling caused by the Philippine Pinatubo eruption in 1991, a slow-down in the mid-2000s and an overall higher rate of retreat since 2000.
