Glacier fluctuations and climate
Regular studies of Tien Shan glaciers begun in 1948, when Then Shan Geographical Research Station in Porkovka (Issik-Kul district) was established. In 1980s L.R. Serebryanny and his team (Serebryanny et al., 1989, Solomina, 1996, 1999 etc.) studied Holocene moraine morphology, chronology, and geomorphic processes. They found out that the climate warming in Tien Shan started ca. 12-9 kyr B.P., continued in the early Holocene and culminated in the middle Holocene. Humidity was low during the mid Holocene. Glaciers retreated up to modern size about 8000-9000 years ago. In the Late Holocene three cold stages were identified by pollen analysis and numerous glacier advances were dated by lichenometry. 14C dating of peat bogs and buried soils bring evidences of glacier retreat ca 6000 and 1000 years ago. "Medieval Warm Period" occurred in the Tien Shan in 7-14 centuries. Its peak was in 10 century with increased temperature and reduced humidity. Most of lichenometrically dated Little Ice Age moraines were deposited in 17 and 19 centuries. They overlay in most cases the earlier moraines of 8-15 centuries.
Tien Shan glaciers advanced in 1850th, 1880th and first and second decades of 20th century according to historical data. The retreat of Tien Shan glaciers from their Little Ice Age maximum extent was estimated using aerial photographs from 1980 to 1985 and maps (1956-1990s). Historical information (since 1880s) was used as indirect control of remote sensing data. The age of moraines in key regions was estimated by lichenometry. On average Tien Shan glaciers have retreated by 989+/-540m, their elevation rose by 151+/-105 m. (Solomina, Barry, and Bodnya, 2004).
Bibliography
Serebryanniy, L.R., Orlov, A.V., Solomina, O.N., 1989. Moraines as a source of glaciological information. Moscow, Nauka Press, 236 pp. (in Russian with English summary)
Savoskul, O. S., Solomina, O.N. (1996). "Late-Holocene glacier variations in the frontal and inner ranges of the Tian Shan, Central Asia. " 61:25-35.
Solomina O.N., 1999. Mountain glaciation of Northern Eurasia in the Holocene. – Moscow, Scientific World Press, 272 pp. (in Russian with English summary)
Solomina O.N., 1996. Long-term variations of mountain glaciers in the former USSR (FSU). Part 2. Dendrochronology and licenometry. – Zeitschrift für Gletcherkunde und Glazialgeologie, Vol. 32, pp. 197-205.
Solomina O.N., Savoskul O.S., Cherkinsky A.E., 1994. Glacier variations, mudflow activity and landscape development in the Aksay Valley (Tian Shan) during the Holocene. – The Holocene, Vol. 4, No. 1, pp. 25-31. (PDF)
Solomina, O., Barry, R., Bodnya, M. (2004). "The retreat of Tien Shan glaciers (Kyrgyzstan) since the Little Ice Age estimated from aerial photographs, lichenometric and historical data." Geographiska Annaler 86A(2): 205-215.
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