Assessing the catastrophic break-up of Briksdalsbreen, Norway, associated with rapid climate change
Assessing the catastrophic break-up of Briksdalsbreen, Norway, associated with rapid climate change
复制标题
评估挪威 Briksdalsbreen 与快速气候变化相关的灾难性解体
DOI：
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发表时间：
2011
影响因子：
2.7
通讯作者：
K. Martinez
中科院分区：
文献类型：
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作者：
J. Hart;K. Rose;R. Waller;David Vaughan;K. Martinez
翻译后摘要：最近的研究引起了人们对快速气候变化对主要冰盖的稳定性的潜在影响的关注。冰川的行为在很大程度上取决于其底部的运行过程和条件。技术的进步使得这些因素得到了检验，它们对冰流的贡献受到了限制。这项研究通过钻孔、录像、探地雷达、差分全球定位系统、水深测量和Glacsweb无线探测器的研究，调查了挪威水生冰川的快速解体。在2000年至2007年期间，Briksdalsbreen急剧萎缩，c。56 × 105 m3的冰从冰舌流失，相当于70 m a−1的速率。这是由于夏季气温升高、降水减少（北大西洋涛动的负相造成）和冰舌断裂增加的综合影响。冰前湖的扩大在布里克达尔斯布林的快速退缩中发挥了关键作用，允许产冰事件，促进冰川边缘的裂缝和波动的含水量。我们认为，水力压裂是每年产生更多裂缝的主要机制，这有利于发展一个有效的冰内排水系统。这使得越来越多的水流入冰床，在冰床中，水被储存在冰下洞穴中，并通过分布式（“缓慢”）排水系统转移。然而，尽管冰下水含量增加，冰的速度在分裂期间保持不变。在Briksdalsbreen观察到的过程和那些与格陵兰岛的冰川的加速和快速退缩之间的比较。
Abstract: Recent research has raised concerns about the potential influence of rapid climate change on the stability of major ice sheets. The behaviour of glaciers is determined largely by the processes and conditions operating at their base. Technological advances have allowed these factors to be examined and their contribution to ice flow constrained. This study investigated the rapid disintegration of an aquatic based Norwegian glacier, through the study of boreholes, video, ground-penetrating radar, differential global positioning system, bathymetry and Glacsweb wireless probes. Briksdalsbreen retreated dramatically between 2000 and 2007, with c. 56 × 105 m3 of ice lost from the glacier tongue, equivalent to a rate of 70 m a−1. This was due to the combined effect of higher summer temperatures, decreased precipitation (resulting from a negative phase of the North Atlantic Oscillation) and increased fracturing of the glacier tongue. The enlargement of a proglacial lake played a key role in Brikdalsbreen's rapid retreat, allowing calving events and promoting crevassing and fluctuating water contents at the glacier margin. We suggest that hydro-fracturing was the dominant mechanism responsible for generating more crevasses each year, which facilitated the development of an efficient englacial drainage system. This fed increasing quantities of water to the bed, where it was stored in subglacial cavities and transferred through a distributed (‘slow') drainage system. However, despite this increase in subglacial water content, ice velocities remained constant during the break-up. Comparisons are made between the processes observed at Briksdalsbreen and those associated with the acceleration and rapid retreat of Greenland's tidewater glaciers.