文章基本信息

标题：Glacier-bed characteristics of midtre Lovénbreen, Svalbard, from high-resolution seismic and radar surveying
本地全文：下载
作者：E.C. King ; A.M. Smith ; T. Murray 等
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2008
卷号：54
期号：184
页码：145-156
DOI：10.3189/002214308784409099
出版社：Cambridge University Press
摘要：We conducted a seismic and radar survey of the central part of midtre Lovénbreen, a small, polythermal valley glacier in Svalbard. We determined the physical properties of the material beneath the glacier by measuring the reflection coefficient of the bed by comparing the energy of the primary and multiple reflections, and deriving the acoustic impedance. By making reasonable assumptions about the properties of the basal ice, we determined the acoustic impedance of the bed material as (6.78 ± 1.53) × 10 6 kg m −2 s −1 . We interpret the material beneath the glacier to be permafrost with up to 50% ice, and we speculate that the material may be frozen talus similar to a deposit observed directly by others beneath another Svalbard glacier. The implication for midtre Lovénbreen is that the basal material beneath the present glacier is not able to support fast flow. We conclude that midtre Lovénbreen has most likely had limited capability for faster flow in the past, with motion dominated by internal deformation. Midtre Lovénbreen is used as a ‘study glacier’ for the scientific community in Svalbard, and a large number of studies have been based there. Our results show that it cannot be used as an analogue for larger glaciers in Svalbard, having distinct basal boundary conditions.