Lenin Glacier — a mountain valley glacier on the northern slope of the Zaalai Range (Pamirs), in Kyrgyzstan (Osh region).
The length of the glacier is 13.5 km, and its area is 55.3 km². An extensive firn basin lies at the foot of Lenin Peak (7134 m), with the firn line at an altitude of 5300 m. The tongue of the glacier descends to 3760 m, from where the Achi-Tash River begins, a left tributary of the Kyzylsu. The right tributary of the glacier is pulsating: in 1945 and 1969, it cracked and advanced by 500 and 1000 m respectively.
On the Zaalai Range, in its most elevated central and eastern sections, there are several large pulsating glaciers, whose movements have been detected and some of which have been closely monitored over the past 30 years. These include the Lenin, Eastern Kyzylsu, Oktyabrsky glaciers, and the glaciers of the upper reaches of the Sauksay River (N 275, Vali, Dzerzhinsky, Small Saukdara). Additionally, there are several complex glaciers with pulsating components (Korzhenevsky and Nura on the northern slope, Uysu and Kurumdy on the southern slope). The movements of their components occur within the general glacier tongues, the very existence of which is defined by systematic injections of ice from the components and the protective role of the moraine cover. According to observations (analysis of repeated space images), this mode is currently characteristic of many complex glaciers, where insufficient nourishment during the overall degradation of glaciation does not allow the movements of individual streams or tributaries to engage the powerful morainic tongue in motion, causing them to fade within its limits, becoming internal to the entire system. The so-called "chukurs" are characteristic of the northern foothills of the Zaalai Range, which, in plan, resemble giant "paws" and are well deciphered in both aerial and space photographs. They may have been formed by the movements of ancient glaciers that completely filled the river valleys and slopes of Zaalai. However, the presence of ancient "paws" significantly lower than the ends of modern glaciers does not serve as evidence of their pulsating regime at present, when most glaciers are degrading.
