Timing of late quaternary glaciations in the Yankti Kuti valley of the upper Kali Ganga catchment, Northern India

Abstract

The Yankti Kuti valley which is located in the transitional climatic zone of the upper Kali Ganga catchment of northern India has witnessed multiple glacier advances since Marine Isotopic Stage 3 (MIS 3). The oldest glacial advance in the valley occurred during early MIS-3 and is dated to 52 ± 3 ka (52.8 ± 3 and 50.4 ± 3 ka), the second advance occurred during late MIS 3 and is dated to 35 ± 2 ka (36.4 ± 1.8 and 34.5 ± 2.2 ka). The termination of this stage occurred at ∼30.3 ± 2 ka and is reflected in the vertical shrinkage of the glacier. The third glacial advance which was more restricted is dated to the Last Glacial Maximum (LGM) 22 ± 1 ka (22.2 ± 1.1 and 21.4 ± 1.2 ka). Following this, a glacial advance is dated to 16.1 ± 1 ka corresponding to the Older Dryas cooling of the late glacial period. A subsequent minor re-advance is dated to 4.3 ± 2.0 ka (4.4 ± 0.4 and 4.2 ± 0.1 ka) and can be attributed to the globally identified 4.2 ka cooling (arid) event. The study is in accordance with earlier observations made from the monsoon-dominated central Himalayan region. It provides a robust chronology and climatic evidence indicating significant ice volume depicted by the moraine height during MIS 3, implying that the moisture-deficient valleys of semi-arid Himalayan regions respond sensitively to enhance precipitation. The study suggests a regional synchronicity of glacier response to climate variability since MIS 3 and was in accordance with the synoptic-scale, climatic perturbation triggered by the North Atlantic millennial-scale climate oscillations.