Glacier surges in the north-west West Kunlun Shan inferred from 1972 to 2017 Landsat imagery

摘要

The West Kunlun Shan lie close to, or are perhaps part of, two significant glaciological phenomena - the High Mountain Asia surge 'supercluster' and the Karakoram Anomaly. However, glaciological studies, and particularly surge studies, in the range are limited. Here, we extend the database of known surges in the region using Landsat imagery and cross-correlation feature tracking. We examine 88 glaciers larger than 1 km(2) in the Hotan Prefecture of Xinjiang, China, and find evidence of nine surges occurring between 1972 and 2017. Glaciers display low active phase velocities (similar to 0.2-1.5 km a(-1)) that show seasonal acceleration in the summer, active phase periods as short as 2 years, and build-up and deceleration phases of months-years. Although these observations display characteristics indicative of both the classic hydrological and thermal switch mechanisms, the surging observed displays a close resemblance to that in the adjacent Karakoram ranges. Furthermore, the majority of the surges occur clustered at the end of a decadal-scale warming period, corroborating previously proposed causal links between climate and surging in the Karakoram. We suggest that the two regions should be considered part of one larger system when considering surge dynamics in High Mountain Asia.