Characterizing the behaviour of surge-type glaciers in the Geladandong Mountain Region, Inner Tibetan Plateau, from 1986 to 2020

摘要

Although surging glaciers in the Geladandong Mountain region represent a small percentage of the Qinghai-Tibet Plateau's glacier population, they can provide valuable insight into the glacier processes, flow instabilities, and fast glacier flow. Here we identify 11 surge-type glaciers and reported the observations of surging behaviour in this region by mapping changes in the terminus position, surface velocity, and elevation of glaciers, using a combination of Landsat and ASTER satellite imagery from 1986 to 2020, TerraSAR-X/TanDEM-X, NASADEM, and topographic maps. Among the 11 surge-type glaciers, nine glaciers started to surge in the 1980s and 1990s, and two glaciers began to surge after 2000. In total, we present 22 surface velocity data sets, which show that the active phases usually last 10-19 years and peak surge velocities are between 30 +/- 1.26 m a(-1) and 100 +/- 1.26 m a(-1). The acceleration phases at the beginning can last for several years, and the deceleration phases at the end last for a maximum of 2 years, and the flow velocity in summer is greater than that in winter. Under the background of global climate warming, no single process is responsible for glacier surges in the Geladandong Mountain region. The dynamic evolution of glacier surges does not fit neatly within either of the classically cited thermal or hydrological models of surging. We hypothesize that the recent glacier surges may be caused by multiple factors. (C) 2021 Elsevier B.V. All rights reserved.