Late Quaternary glacial advances and equilibrium-line altitude changes in a semi-arid region, Suru Basin, western Himalaya

Abstract

This study examines the late Quaternary glacial history of Suru Basin and its associated tributary valleys (i.e., Achambur, Kangriz, Shafat, Rangdum, and Pensilugnpa), western Himalaya, based on the data collected from field surveys (2015–2019), satellite images, and optically stimulated luminescence (OSL) dating. The glaciers in Suru Basin have fluctuated greatly throughout the Marine Isotope Stages (MIS) 3 and 2 to the Little Ice Age (LIA), and are critical in understanding the linkages between regional and global climate change. Here, we present a detailed record of five major glacial advances of decreasing magnitude, dated 33–23 ka, 16 ka, 13–11 ka, 10–7.3 ka, 2.8–2.3 ka, and a minor advance dated 0.7–0.4 ka. These five major glacial advances are named from oldest to youngest as Suru-I to V, based on their optical chronology, geographical position, moraine stratigraphy, and glacially polished rock surfaces. Whereas, the equilibrium-line altitude (ELA) ascended by ∼538 m from the oldest glacial advance (Suru-I) to the present-day, followed by four other events (Suru-II, III, IV, and V) with ascended ELAs of ∼522, ∼399, ∼243, and 215 m, respectively. Suru Basin has lost ∼502 km2 in its glaciated area and ∼163 km3 in ice volume from Suru-I to the present-day. The magnitude of glacier extent decreased from the MIS 3 and 2, early to late-Holocene, and LIA. The timing of these glacial advances is coarsely in agreement with North Atlantic millennial-scale climate oscillations (Heinrich events), signifying the probable correlation between these abrupt climate changes and glacial fluctuations in this semi-arid region of the Himalaya.