Recent Surge Behavior of Walsh Glacier Revealed by Remote Sensing Data.

摘要: Many surge-type glaciers are present on the St. Elias Mountains, but a detailed study surge behavior of is still missing. In this study, we used remote sensing data to reveal glacier behavior, focusing recent at Walsh Glacier, which was reported have surged once in 1960s. Glacial velocities were derived using cross-correlation algorithm, and changes medial moraines interpreted based Landsat images. The digital elevation model (DEM) difference method applied Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) DEMs evaluate surface glacier. results showed that initiated near conjunction eastern northern branches, then quickly spread downward. period almost three years, with an active phase less than two years. advancing speed front much large maximum ice velocity ≈14 m/d observed during phase. Summer speed-ups winter speed-up from data, being more obvious Changes suggested branch affected by surge. DEM differencing receiving zone thickened up about 140 m, upstream reservoir became thinner. These behaviors, as characterized gave us insights into dynamics Glacier.