Brief communication: An ice-debris avalanche in the Nupchu Valley, Kanchenjunga Conservation Area, eastern Nepal

Abstract

Beginning in December 2020, a series of small to medium, torrent-like pulses commenced upon a historic debris cone located within the Nupchu Valley, Kanchenjunga Conservation Area (KCA), Nepal. Sometime between 16 and 21 August 2022 a comparatively large ice-debris avalanche event occurred, covering an area of 0.6 km2 with a total estimated volume of order 106 m3. The area of the debris cone left by the August 2022 event increased the historic debris cone area by 0.2 km2 (total area 0.6 km2). Although no human or livestock deaths occurred, the increase in torrent-like pulses of debris upon this historic debris cone since 2020 exemplifies a style of mass movement that may become increasingly common as air temperatures rise in the region. Although the magnitude of this event was small compared to events like the 2021 Chamoli avalanche, the widespread distribution and frequency of comparable events present a substantial, and potentially increasing, hazard across High Mountain Asia.