Timing and climatic drivers for glaciation across monsoon-influenced regions of the Himalayan–Tibetan orogen

Late Holocene Glacier Dynamics in the Miyar Basin, Lahaul Himalaya, India

“…Nevertheless, great care was taken in choosing samples and further correlation with adjoining valleys, providing confidence in our sampling technique and the obtained results. Confidence in the validity of our data is further strengthened by reasonable agreement with existing chronologies from the adjoining Himalaya region, e.g., Lahaul Himalaya [25], Tons and Thangi valleys [12,25,44], Gangotri Glacier [19,68], eastern Nanda Devi region [73], and the Central Himalaya [14].…”

“…OSL samples from the Gumba lacustrine fill (8 ± 2 ka, 8 ± 1 ka, and 10 ± 1 ka) suggested that the maximum extent of the Gumba Glacier occurred~10-8 ka BP. We assign these advances to the early Holocene intensification of the ISM [14,74], which is also supported by radiocarbon dates obtained from peat bog at Chandratal, indicating that the peat growth began 9160 ± 70 years BP [24], thus inferring an increase in either temperature or precipitation in the Lahaul Himalaya during the early Holocene. However, this idea of increased temperatures in the early Holocene times contradicts the idea that this period was a time of extensive glaciation in the Miyar basin.…”

“…Moreover, it is suggested that the most extensive glacial advances in the Himalaya and Tibetan region generally occurred during the early Holocene, between~11.5 ka and~8.0 ka [5,14,25,73,75,77], and that this was related to both an increase in monsoon precipitation [78] and lower temperatures [23]. However, the extent of glaciation and ELA depressions during the early Holocene vary considerably between regions, and a complex pattern of glaciation has been observed, with some regions having evidence for glacial advances at times, whereas others showed no advances [14,19,21,74].…”

“…Practically in the context of contemporary global warming, climate variability, and associated societal impacts, it is important to characterize and quantify past glacial changes for a better assessment of regional and global forcing factors for future glacier behavior as a water resource [11,12]. Yet, despite the geological and societal importance of this region, the nature and dynamics of glaciers of this region throughout the Quaternary are not well understood [11,13,14]. The growing availability of chronological data in recent years has emerged, yet there is no general consensus concerning the timing, extent, and climatic forcing of glaciations in the Himalayan region [12,15,16].…”

Paleoglaciation of the Tibetan Plateau and surrounding mountains based on exposure ages and ELA depression estimates

“…The chronological approach used here with χ 2 R and mean/max exposure age tests differs from the kernel density smoothing approach of two recent studies investigating the timing of glaciation across the Tibetan Plateau region (Dortch et al, 2013;Murari et al, 2014). Dortch et al (2013) and Murari et al (2014) defined 19 and 27 regional glacial stages for the western and southern/eastern parts of the Tibetan Plateau region, respectively, ranging up to more than 300 ka in age. Both approaches yield a large number of ages in the 10-30 ka range and considerable variation across the Tibetan Plateau and the surrounding mountains.…”