Late-Holocene glacier variations in the frontal and inner ranges of the Tian Shan, central Asia

Abstract

Evidence for the timing and extent of late-Holocene glacial advances in the Tian Shan mountains, central Asia, is based on lichenometric and radiocarbon dating of end-moraines. Three phases of glacial advance occurred at 1700-2100 and 1100-1300 lichenometric (L) years ago, and then during the 'Little Ice Age', 150- 700 (L) years ago. Differences in the pattern of glacier variations between the northwestern frontal and inner areas of the Tian Shan are reflected in the equilibrium line altitude (ELA) depression of 23 glaciers studied at nine selected sites. The peripheral glaciers appear to have been significantly more extensive during late- Holocene advances than the glaciers of the inner areas. This difference seems to be explained by regional differences in humidification: in the northwestern periphery of the Tian Shan, the cold periods of the late Holocene were more humid than the warm period of the mid-Holocene; whereas, in the inner areas, the pattern of climate changes was the opposite (a warm and humid mid-Holocene was followed by a cold and arid late Holocene).

Glacier retreat and climatic variability in the eastern Terskey–Alatoo, inner Tien Shan between the middle of the 19th century and beginning of the 21st century

“…2), the average annual accumulation and ablation were 762 and 1160 mm of water equivalent (mm w. e.) respectively in 1957-1997 resulting in an average negative mass balance of 438 mm w. e. (Dyurgerov, 2002; Section 5 of this paper). Glaciers of the TerskeyAlatoo repeatedly advanced and retreated throughout the Holocene and the latest period of advance was dated by Savoskul and Solomina (1996), Solomina (2000), and Solomina et al (2004) to with the majority of terminal and side moraines forming in the middle of the 19th century.…”

“…4). Most of the moraines formed during the 1830s-1880s period (Savoskul and Solomina, 1996;Solomina, 2000;Solomina et al, 2004). To simplify statistical analysis, 1860 was taken as an average date of the formation of the latest LIA moraines.…”

Record of glacier variations during the last glacial in the Turkestan range of the Pamir-Alay, Kyrgyz Republic

“…Both the small glacier expansion and the presence of a moraine with dense vegetation in the glacier frontal area indicate that moraine AU6 formed by the Asan-Usin glacier expansion during the late Holocene. Evidence of small glacier expansion in the late Holocene has also been found in the Tien Shan and the Pamir-Alay mountains (Savoskul and Solomina, 1996; Zech and others, 2000).…”

Variability in precipitation, temperature and river runoff in W Central Asia during the past ~2000yrs

“…Besides the high stand from the end of the 19th century to the beginning of the 20th century AD, other high stands could be Yang et al, 2002;Yang et al, 2009) and a tree-ring record from Central Asia (d) (X.P. Yang et al, 2002) and timing of glacier advances in the Tien Shan (Savoskul and Solomina, 1996) and Pamir Alay (Narama and Okuno, 2006) during the past 2000 yrs (d). Grey shadings and grey broken lines in the uppermost part are matching high lake water mineralization (VNIR record; logarithmic scale of relative units) with low ice accumulation and increased temperature.…”

“…Glacier advances in different regions of Tien Shan occurred from 100 BC-AD 300, AD 1400-1500, AD 1700-1750 and AD 1800-1850 (Savoskul and Solomina, 1996). From the Pamir Alay (SW headwater area of Syr Darya), glacier advances were confined to AD 250-440, the second half of the 15th to 16th centuries and the mid-17th century AD (Narama and Okuno, 2006).…”