Morphology and variations of glacial drainage basins in the King George Island ice field, Antarctica
Morphology and variations of glacial drainage basins in the King George Island ice field, Antarctica
复制标题
南极乔治王岛冰原冰川流域的形态和变化
作者：
J. Simões;U. F. Bremer;F. Aquino;F. Ferron
摘要：乔治王岛是西南极洲南设得兰群岛中最大的岛屿（1250 平方公里），其地球观测系统 (SPOT) 镶嵌图显示了其主要形态特征。划定了三个主要冰穹和70个冰川流域，覆盖乔治王岛面积的92.7%，受冰下形态强烈控制，并由相对快速移动的潮水出口冰川排水。四十年来，冰锋普遍后退，在岛的东侧（布兰斯菲尔德海峡）更为严重，导致冰川覆盖面积损失约 7%。表面雪消退源自 SPOT 多光谱图像，并与现场观测相结合，获得了瞬态雪线高程。估计后者已从 1950 年代中期的约 200-250 m 上升到 1988 年的 300-350 m。点无线电回波探测勘测提供了基岩形态的概述。
Abstract A Système probatoire pour l’observation de la terre (SPOT) mosaic of King George Island, the largest (1250 Km2) of the South Shetland Islands, West Antarctica, shows its major morphological features. Three main ice domes and 70 glacier drainage basins, covering 92.7% of the King George Island area, strongly controlled by the subglacial morphology and drained by relatively fast-moving tidewater outlet glaciers, were delineated. A general retreat of ice fronts through four decades, more intensely on the eastern side of the island (to the Bransfield Strait), resulted in the loss of about 7% of the glacial cover area. Superficial snow fades were derived from SPOT multispectral imagery and, together with field observations, allowed the transient-snowline elevation to be obtained The latter is estimated to have risen from about 200-250 m in the mid-1950s to 300-350 m by 1988. Spot radio-echo sounding surveys give an overview of the bedrock morphology.