The role of ice thickness and bed properties on the dynamics of the enhanced-flow tributaries of Bailey Ice Stream and Slessor Glacier, East Antarctica
The role of ice thickness and bed properties on the dynamics of the enhanced-flow tributaries of Bailey Ice Stream and Slessor Glacier, East Antarctica
复制标题
冰厚度和床特性对南极洲东部贝利冰流和斯莱索尔冰川增强流动支流动力学的作用
作者：
D. Rippin;J. Bamber;M. Siegert;D. Vaughan;H. Corr
在东南极洲科茨地的贝利冰流和斯莱瑟冰川上游进行的航空无线电回波探测研究表明，增强流支流与边界明确的相对较厚的冰区有关，并被相对较薄的冰区相互隔开。数值模拟研究表明，虽然内部冰变形可能占所有观测到的流量在支流间的地区和大部分在Slesser支流，贝利支流流量的一个显着比例是由于基础运动。此外，深度校正的基础反射功率的调查表明，床下的贝利和Slessor增强流支流是明显比在缓慢移动的支流间的地区更平滑。因此，建议加强运动内贝利支流（也可能是Slesser）可能会促进减少基底粗糙度，造成的水和/或沉积物的积累冰下山谷，或由侵蚀和平滑的床障碍。
Abstract Airborne radio-echo sounding investigations in the upper reaches of Bailey Ice Stream and Slessor Glacier, Coats Land, East Antarctica, have shown that enhanced-flow tributaries are associated with well-defined areas of relatively thicker ice, and are separated from each other by areas of relatively thinner ice. A numerical modelling study has revealed that while internal ice deformation might account for all the observed flow in inter-tributary areas and the majority in the Slessor tributaries, a significant proportion of the flow of Bailey tributary is attributable to basal motion. Further, investigations of depth-corrected basal reflection power indicate that the bed underlying both Bailey and Slessor enhanced-flow tributaries is significantly smoother than in the slower-moving inter-tributary areas. It is thus proposed that enhanced motion within Bailey tributary (and also perhaps Slessor) may be facilitated by a reduction in basal roughness, caused by the accumulation of water and/or sediments within subglacial valleys, or by the erosion and smoothing of bed obstacles.