Geomorphology of the central and frontal Rongbuk glacier area (Mount Everest, Tibet)

Abstract

This report details the results of some recent geomorphological studies, surveys and mappings of the higher parts of the northern (Tibetan) area of Mount Everest, along the Rongbuk glacier. Its retreat is causing extensive gravitational phenomena involving both ice/snow and rock/debris. At the same time, the spatial reduction and the retreat of the glacier tongues are promoting new conditions for superficial and supraglacial run-off, concentrated in the terminus area, generating a direct transition from glacial to paraglacial processes over short distance and time scales. The monitoring and mapping of processes and landforms, carried out in the field with GIS technology, provided early-control of survey data. The availability of digital data collected or specifically implemented (Digital Elevation Model or satellite imageries) and survey data, also in real time and at low-cost, made possible the reconstruction of the morphological evolution, as a «field pre-view», as well as providing a safe approach to field activity. The results of the surveys are presented as cartography and descriptions of processes and landforms, with particular attention to active geomorphological hazards, such as ice falls, rock/slope instability, small GLOFs (Glacial Outburst Floods) at ice termini and to consequent risk.