Meltwater drainage and iceberg calving observed in high-spatiotemporal resolution at Helheim Glacier, Greenland
Meltwater drainage and iceberg calving observed in high-spatiotemporal resolution at Helheim Glacier, Greenland
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在格陵兰岛赫尔海姆冰川高时空分辨率下观测到的融水排水和冰山崩解
DOI：
10.1017/jog.2021.141
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发表时间：
2021
影响因子：
3.4
通讯作者：
Finnegan, David C.
中科院分区：
文献类型：
--
作者：
Melton, Sierra M.;Alley, Richard B.;Anandakrishnan, Sridhar;Parizek, Byron R.;Shahin, Michael G.;Stearns, Leigh A.;LeWinter, Adam L.;Finnegan, David C.
海洋冰川通过融化和冰山崩解而失去质量，我们发现融水排水系统影响了东格陵兰岛潮汐冰川Helheim冰川的崩解时间。融水在海尔海姆冰川的末端形成了浮力的冰下排放羽流，它沿着冰川前缘上升，穿过冰川表面。在这里，我们使用高分辨率卫星和延时图像来观察2011年至2019年期间该融水羽流的地表表达，以及羽流的时间和位置与裂冰和冰川上融水池的时间和位置的比较。即使在冰川前进和后退的过程中，羽流也始终出现在中央末端，由一个与冰川上水相连的完善的渠化排水系统提供补给。所有的全层产犊期，无论是板状的还是非板状的，都是在时间或空间上与表面羽流分开的。我们假设冰下水文的变异性和基底耦合驱动了冰下流量羽流与全层崩解之间的逆关系。地表羽流可能表明一个低压冰下排水系统和接地终端，而全层产裂则反映了一个处于或接近浮选的终端。因此，我们对羽流外观和全层崩解的记录代表了赫尔海姆冰川长期以来的基本状态。
Marine-terminating glaciers lose mass through melting and iceberg calving, and we find that meltwater drainage systems influence calving timing at Helheim Glacier, a tidewater glacier in East Greenland. Meltwater feeds a buoyant subglacial discharge plume at the terminus of Helheim Glacier, which rises along the glacial front and surfaces through the mélange. Here, we use high-resolution satellite and time-lapse imagery to observe the surface expression of this meltwater plume and how plume timing and location compare with that of calving and supraglacial meltwater pooling from 2011 to 2019. The plume consistently appeared at the central terminus even as the glacier advanced and retreated, fed by a well-established channelized drainage system with connections to supraglacial water. All full-thickness calving episodes, both tabular and non-tabular, were separated from the surfacing plume by either time or by space. We hypothesize that variability in subglacial hydrology and basal coupling drive this inverse relationship between subglacial discharge plumes and full-thickness calving. Surfacing plumes likely indicate a low-pressure subglacial drainage system and grounded terminus, while full-thickness calving occurrence reflects a terminus at or close to flotation. Our records of plume appearance and full-thickness calving therefore represent proxies for the grounding state of Helheim Glacier through time.
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影响因子：
2.9
作者：
K. Poinar;I. Joughin;D. Lilien;L. Brucker;L. Kehrl;S. Nowicki
通讯作者：
K. Poinar;I. Joughin;D. Lilien;L. Brucker;L. Kehrl;S. Nowicki
冰山崩解过程中的冰川逆向运动和冰川地震的原因
影响因子：
56.9
作者：
T. Murray;M. Nettles;N. Selmes;L. M. Cathles;J. Burton;T. James;S. Edwards;I. Martin;T. O'Farrell;R. Aspey;I. Rutt;T. Baugé
通讯作者：
T. Baugé
格陵兰潮水冰川前部通量平衡的巨大空间变化
DOI：
10.5194/tc-13-911-2019
发表时间：
2019
期刊：
The Cryosphere
影响因子：
--
作者：
Wagner, Till J.;Straneo, Fiamma;Richards, Clark G.;Slater, Donald A.;Stevens, Laura A.;Das, Sarah B.;Singh, Hanumant
通讯作者：
Singh, Hanumant
影响因子：
2.9
作者：
Alley, R. B.;Cuffey, K. M.;Zoet, L. K.
通讯作者：
Zoet, L. K.
影响因子：
3.9
作者：
Kehrl, L. M.;Joughin, I.;Krieger, L.
通讯作者：
Krieger, L.