资源环境科技发展态势分析平台

A decrease in the mass and volume of Western Palmer Land has raised the prospect that ice speed has increased in this marine-based sector of Antarctica. To assess this possibility, we measure ice velocity over 25years using satellite imagery and an optimized modeling approach. More than 30 unnamed outlet glaciers drain the 800km coastline of Western Palmer Land at speeds ranging from 0.5 to 2.5m/d, interspersed with near-stagnant ice. Between 1992 and 2015, most of the outlet glaciers sped up by 0.2 to 0.3m/d, leading to a 13% increase in ice flow and a 15km(3)/yr increase in ice discharge across the sector as a whole. Speedup is greatest where glaciers are grounded more than 300m below sea level, consistent with a loss of buttressing caused by ice shelf thinning in a region of shoaling warm circumpolar water.