Climatic and Tectonic Significance of Taboche Lake, Khumbu Region, Nepal

Abstract

The Mount Everest region is characterized by its alpine glacial environment. In an effort to understand environmental change in the area, our team cored Taboche Lake, situated at 4,712 m along the western margin of the lateral moraine of the Ngozumpa Glacier. This research catalogues past earthquakes using geological records of the lake core that are important for the assessment of future earthquake hazards in the region. To achieve the aims of the study, core grain size characteristics and internal sedimentary structures from CT scan tomography, were coupled with radiocarbon dating of organic matter preserved in the core to reconstruct the environmental history of Loboche Lake. The 58 cm-long core consists of laminated silty sands and sandy silts with particle diameters less than 2 mm, covering ∼ 2,000 years of sedimentation history. Syn-sedimentary deformational structure, folding of sediments, rhythmically alternating dark- and light-coloured laminations, and turbidites are discussed in terms of their origins as past climatic and tectonic indicators.