A fault-bounded palaeo-lake basin preserved beneath the Greenland Ice Sheet
A fault-bounded palaeo-lake basin preserved beneath the Greenland Ice Sheet
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格陵兰冰盖下保存的断层古湖盆
DOI：
10.1016/j.epsl.2020.116647
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发表时间：
2021
影响因子：
5.3
通讯作者：
Tinto, Kirsty J.
中科院分区：
文献类型：
--
作者：
Paxman, Guy J.G.;Austermann, Jacqueline;Tinto, Kirsty J.
冰下地形不仅对当代冰盖动态具有强有力的控制作用，而且还提供了与过去冰期和间冰期条件有关的景观演化的重要长期记录。特别是，格陵兰冰盖下的河床地形具有过去景观演变过程的特征，这些过程记录了冰盖自形成以来的发展。在这里，我们提出的证据，从航空无线电回波探测，重力和磁力数据封闭的古湖盆位于格陵兰岛西北部的冰盖下。地貌分析和水文模型表明，该盆地曾经有一个湖泊，表面积达1.71万平方公里，体积达1.58万立方公里。该盆地和相关的地形控制保存的古河流通道网络的组织，这表明该盆地早于格陵兰西北部广泛的冰川作用。我们使用弯曲建模表明，盆地和周围地形的形态是一致的弹性板块弯曲驱动的机械位移沿着一个正断层界定盆地边缘。对重力和磁力异常的分析表明，该盆地含有一个厚达1.2公里的沉积充填层，其中可能含有格陵兰西北部过去冰盖范围和环境条件的宝贵记录。因此，我们建议，这个新确定的古湖盆可能是一个很有前途的目标，未来收购的地面活动源地震数据和潜在的恢复冰下物质的冰下钻探计划。
Subglacial topography not only exerts strong controls on contemporary ice sheet dynamics, but also provides an important long-term record of landscape evolution pertaining to past glacial and interglacial conditions. In particular, the bed topography beneath the Greenland Ice Sheet bears the signatures of past processes of landscape evolution that record the development of the ice sheet since its inception. Here we present evidence from airborne radio-echo sounding, gravity, and magnetic data for an enclosed palaeo-lake basin situated beneath the ice sheet in northwest Greenland. Geomorphological analysis and hydrological modelling indicate that the basin once hosted a lake with a surface area of up to ∼7,100 km2and a volume of up to ∼580 km3. The basin and associated topography control the organisation of a preserved palaeo-fluvial channel network, suggesting that the basin pre-dates widespread glaciation in northwest Greenland. We use flexural modelling to show that the morphology of the basin and surrounding topography is consistent with elastic plate flexure driven by mechanical displacement along a normal fault bounding the basin margin. Analysis of gravity and magnetic anomalies indicates that the basin contains a sedimentary infill up to ∼1.2 km thick, which may contain valuable records of past ice sheet extent and environmental conditions in northwest Greenland. We therefore propose that this newly identified palaeo-lake basin may be a promising target for future acquisition of ground-based active source seismic data and potential recovery of subglacial material by sub-ice drilling programs.
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影响因子：
--
作者：
G. Oakey;J. Chalmers
通讯作者：
G. Oakey;J. Chalmers
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影响因子：
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作者：
B. Keisling;L. T. Nielsen;C. Hvidberg;R. Nuterman;R. DeConto
通讯作者：
R. DeConto
影响因子：
5.8
作者：
Livingstone, Stephen J.;Chu, Winnie;Kingslake, Jonathan
通讯作者：
Kingslake, Jonathan
影响因子：
30.7
作者：
F. Pattyn;C. Ritz;Edward Hanna;X. Asay-Davis;R. DeConto;G. Durand;L. Favier;X. Fettweis;H. Goe
通讯作者：
F. Pattyn;C. Ritz;Edward Hanna;X. Asay-Davis;R. DeConto;G. Durand;L. Favier;X. Fettweis;H. Goe
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DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
C. J. van der Veen;T. Leftwich;R. von Frese;B. Csathó;J. Li
通讯作者：
J. Li