existed 11 outlet glaciers emerging from a summit snow mass that covered about . At that time, it was found that the present glaciers on the summit of Ararat extend as low as an elevation of on the north-facing slope, and an elevation of on its south-facing slope. Using pre-existing aerial imagery and remote sensing data, Sarıkaya and others studied the extent of the ice cap on Mount Ararat between 1976 and 2011. They discovered that this ice cap had shrunk to by 1976 and to by 2011. They calculated that between 1976 and 2011, the ice cap on top of Mount Ararat had lost 29% of its total area at an average rate of ice loss of per year over 35 years. This rate is consistent with the general rates of retreat of other Turkish summit glaciers and ice caps that have been documented by other studies. According to a 2020 study by Yalcin, "if the glacial withdrawals continue with the same acceleration, the permanent glacier will likely turn into a temporary glacier by 2065." Blumenthal estimated that the snow line had been as low as in elevation during the Late Pleistocene. Such a snow line would have created an ice cap of in extent. However, he observed a lack of any clear evidence of prehistoric moraines other than those which were close to the 1958 glacier tongues. Blumenthal explained the absence of such moraines by the lack of confining ridges to control glaciers, insufficient debris load in the ice to form moraines, and their burial by later eruptions. Years later, Birman observed on the south-facing slopes a possible moraine that extends at least in altitude below the base of the 1958 ice cap at an elevation of . He also found two morainal deposits that were created by a Mount Ararat valley glacier of Pleistocene, possibly Wisconsinan (Last Glacial Maximum) age, downvalley from Lake Balık. The higher moraine lies at an altitude of about and the lower moraine lies at an altitude of about . The lower moraine occurs about downstream from Lake Balık. Both moraines are about high. It is suspected that Lake Balık occupies a glacial basin. Geology Mount Ararat is a polygenic, compound stratovolcano. Covering an area of , it is the largest volcanic edifice within the region. Along its northwest–southeast trending long axis, Mount Ararat is about long and is about long along its