Late-Holocene climatic record from a glacial lake in Ladakh range, Trans-Himalaya, India

Abstract

A multi-proxy study using mineral magnetism, sediment texture, total organic content, palynofacies and diatoms was conducted in one of the highest proglacial lake situated at North Pulu (5098 m a.s.l.) of Ladakh sector of NW Himalaya – a high-altitude cold arid desert. This study presents climatic variations that occurred between 5412 and 419 cal. yr BP (14C AMS chronology). Directly recharged by meltwater from Khardung glacier, this proglacial lake provides a complete record of past climatic variability due to continuous sedimentation and this attribute makes it an exceptionally important geochronological archive for climatic studies. This first high-resolution palaeolimnology record from Karakoram Himalayas shows intermittent warm and cold periods in which the cold events are short but sudden events recorded at 5700, 4600, 4400, 4200, 3800, 3500, 3000, 1800–1700, 1200, 910, 840 and 770–710 cal. yr BP. Between 5412 and 4840 cal. yr BP, an oxic lake condition existed with freeze–thaw action, prominent weathering, more sediment generation and less organic productivity. The following period till 4410 cal. yr BP was cold and dry, a transition phase to the next warmer phase. Between 4410 and 2064 cal. yr BP, climate ameliorated to somewhat moderate warm climate and relatively high lake levels. Glacial melting due to a warm climate resulted in high TOC%, and well-preserved OM indicating reducing conditions in the lake system. From 2064 to 1711 cal. yr BP cold conditions and from 1272 to 1182 cal. yr BP warmer conditions are seen with large appearance in Amphora ovalis indicating increased nutrients input and moderate water levels. This was followed by warmer climatic conditions between 1182 and 958 cal. yr BP. LIA in the region is experienced between 958 and 644 cal. yr BP with anoxic condition. Between 644 and 419 cal. yr BP, climatic condition was again warmer comparatively. However, this warming was not so severe and only had a regional impact.

Palaeoclimatic variability during last eight millennia from a morainal lake in Zanskar, northwest Himalaya, India

“…Based on δ 13 C, TOC and pollen data, Rawat et al (2015) have also inferred moderate ISM (punctuated by a wet spell) during the late Holocene in the climatologically similar Chandra Valley. The gradually improving hydroclimatic during the later part of the Holocene have also been reported in a number of studies from the adjoining valleys in Ladakh (Ali et al, 2020;Joshi et al, 2021;Phartiyal et al, 2020;2021a;Fig. 6).…”

“…Glaciers are believed to be among the most sensitive terrestrial recorders of climatic changes because they respond to the combined influence of precipitation (snowfall) and temperature (Pratt-Sitaula et al, 2011), and these changes are well recorded in the glacial lake sediments. In a range of spatial scales, different proxies, reflect varying impact of environmental factors and display varying strengths, limitations, and responses, therefore multi-proxy studies are desirable, as they will better reflect local to regional climatic conditions (Kathayat et al, 2017;Srivastava et al, 2018;Ali et al, 2020;Phartiyal et al, 2020). Palaeoenvironmental and palaeoclimatic reconstructions on lake sediments and the organic matter contained in it have generally been used in the Himalayan region, especially for alpine lake where organic matter could well represent the environment and climate fluctuations (Rawat et al, 2015;Phartiyal et al, 2020;2021a).…”

“…In a range of spatial scales, different proxies, reflect varying impact of environmental factors and display varying strengths, limitations, and responses, therefore multi-proxy studies are desirable, as they will better reflect local to regional climatic conditions (Kathayat et al, 2017;Srivastava et al, 2018;Ali et al, 2020;Phartiyal et al, 2020). Palaeoenvironmental and palaeoclimatic reconstructions on lake sediments and the organic matter contained in it have generally been used in the Himalayan region, especially for alpine lake where organic matter could well represent the environment and climate fluctuations (Rawat et al, 2015;Phartiyal et al, 2020;2021a). Hence with the above facts in view, we sampled a relict morainal lake deposit at Khangok, located south-east of the Padam Village, Zanskar Valley (transitional zone between ISM and Westerlies), with an objective to understand the spatial structure of mid-late Holocene climate changes and try to reveal the factors that are responsible for the sub-millennial scale climate variability.…”

Prospects of Astrogeology and Astrobiology researches in India: Ladakh as an example

“…These layers are very good to study the microbes and microbiota adapted to the extremely low temperatures. The Khardungla Pass hosts the South Pulu and the North Pulu lakes and has been studied for diatoms and palynofacies along with the other physical and chemical proxies (Phartiyal et al, 2020a, b;. While Yaya Tso (Fig.…”

Himalayan Blue Pine Deduced Precipitation Record from Cold Arid Lahaul–Spiti, Himachal Pradesh, India

“…These observational records are inadequate to explain the long-term climatic variability of the region in terms of precipitation, temperature, snowfall etc. Therefore, to fill the data void and extends the existing records back to the centuries, high-resolution proxies such as tree-ring, lake sediments, ice cores, and speleothems have been studied over the decades from the Himalaya (Overpeck et al, 2005;Joshi et al, 2017;Phartiyal et al, 2020;Dahe et al, 2021;Kumar et al, 2021). However, to develop high-resolution annually resolved climatic records from centuries to millennium tree-rings proved its utility among all other proxies in the past few decades (Yadav and Park, 2000;Cook et al, 2003;Yadav et al, 2004;Tredyte et al, 2006;Singh et al, 2006Singh et al, , 2009Cook et al, 2010;Yadav, 2011aYadav, , b, 2012Yadav, , 2013Yadav and Bhutiyani, 2013;Yadava et al, 2016;Singh et al, 2017;Yadav et al, 2017).…”