High-frequency Holocene glacier fluctuations in the Himalayan-Tibetan orogen

Saha, Sourav; Owen, Lewis A.; Orr, Elizabeth N.; Caffee, Marc W.

Abstract

Holocene glacial chronostratigraphies in glaciated valleys spread throughout the Himalayan-Tibetan orogen, including the Himalaya, Tibet, Pamir, and Tian Shan, are developed using a landsystems approach, detailed geomorphic mapping, and new and published 10Be surface exposure dating. New studies in the Kulti valley of Lahul and the Parkachik valley of the Nun Kun massif of the Himalaya of northern India define three glacier advances at ∼14.7, 12.2, 0.5 ka, in addition to one historically dated late 19th Century advance in the Kulti valley, and one Late Holocene advance at ∼0.2 ka in the Parkachik valley. Three major climatic groups (subdivided into five climatic zones) are defined across the orogen using Cluster Analysis (CA) and Principal Component Analysis (PCA) to identify glaciated regions with comparable climatic characteristics to evaluate the timing, and extent of Holocene glacier advances across these regions. Our regional analyses across the Himalayan-Tibetan orogen suggest at least one Lateglacial (∼15.3–11.8 ka) and five Himalayan-Tibetan Holocene glacial stages (HTHS) at ∼11.5–9.5, ∼8.8–7.7, ∼7.0–3.2, ∼2.3–1.0, and <1 ka. The extent (amplitude) of glacier advances in 77 glaciated valleys is reconstructed and defined using equilibrium-line altitudes (ELAs). Modern glacier hypsometries are also assessed to help explain the intra-regional variations in glacier amplitudes during each regional glacier advance. A linear inverse glacier flow model is used to decipher the net changes in temperature (ΔT) between periods of reconstructed regional glacier advances in 66 glaciated valleys across different climatic regions throughout the orogen. The 10Be, ELAs, and ΔT data suggest enhanced monsoonal and increased precipitation during the Early Holocene, followed by relative cooling and increased aridity during the Mid- and Late Holocene that influenced glaciation. The sublimation-dominated cold-based glaciers in the northern regions of Himalayan-Tibetan orogen are more affected during these shifts in climate than the temperate glaciers in the south.

Citation

Saha, S., Owen, L. A., Orr, E. N., & Caffee, M. W. (2019). High-frequency Holocene glacier fluctuations in the Himalayan-Tibetan orogen. Quaternary Science Reviews, 220, 372-400. https://doi.org/10.1016/j.quascirev.2019.07.021

• Journal Article Type: Article
• Online Publication Date: Aug 24, 2019
• Publication Date: Sep 15, 2019
• Deposit Date: Sep 2, 2022
• Journal: Quaternary Science Reviews
• Print ISSN: 0277-3791
• Electronic ISSN: 1873-457X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 220
• Pages: 372-400
• DOI: https://doi.org/10.1016/j.quascirev.2019.07.021
• Public URL: https://durham-repository.worktribe.com/output/1193297