Basal channels drive active surface hydrology and transverse ice shelf fracture.
Basal channels drive active surface hydrology and transverse ice shelf fracture.
复制标题
DOI：
10.1126/sciadv.aao7212
复制
发表时间：
2018-06
期刊：
影响因子：
13.6
通讯作者：
Zappa CJ
中科院分区：
文献类型：
--
作者：
Dow CF;Lee WS;Greenbaum JS;Greene CA;Blankenship DD;Poinar K;Forrest AL;Young DA;Zappa CJ
冰架底部的沟槽会造成横向断裂，地表河流会加剧这种断裂，最终导致崩解。冰架通过摩擦阻力控制海平面上升，这减缓了冰川冰向大海的流动。南极洲周围的证据表明，冰架正在变薄和变弱，这主要是由于温暖的海水进入冰架洞穴。我们已经确定了一种冰架失稳的机制，即冰架下方的底部通道导致冰层变薄，从而驱动垂直于流动的破裂。这些水道还会导致冰面变形，从而将冰上河流引向横向裂缝。我们报告了直接证据表明，2016年罗斯海南森冰架的一次重大崩解事件是这种沟道化变薄驱动的断裂的结果，并证明在格陵兰岛和南极洲的其他地方也存在类似的基底沟道驱动的横向断裂。如果海洋和气温上升导致冰架基面和表层融化增加，冰架将越来越容易受到基面航道不稳定的串联效应的影响。
Ice shelf basal channels cause transverse fractures that can be exacerbated by surface rivers, culminating in calving. Ice shelves control sea-level rise through frictional resistance, which slows the seaward flow of grounded glacial ice. Evidence from around Antarctica indicates that ice shelves are thinning and weakening, primarily driven by warm ocean water entering into the shelf cavities. We have identified a mechanism for ice shelf destabilization where basal channels underneath the shelves cause ice thinning that drives fracture perpendicular to flow. These channels also result in ice surface deformation, which diverts supraglacial rivers into the transverse fractures. We report direct evidence that a major 2016 calving event at Nansen Ice Shelf in the Ross Sea was the result of fracture driven by such channelized thinning and demonstrate that similar basal channel–driven transverse fractures occur elsewhere in Greenland and Antarctica. In the event of increased basal and surface melt resulting from rising ocean and air temperatures, ice shelves will become increasingly vulnerable to these tandem effects of basal channel destabilization.
登录
查看更多内容
影响因子：
13.5
作者：
Fahnestock, Mark;Scambos, Ted;Klinger, Marin
通讯作者：
Klinger, Marin
影响因子：
5.2
作者：
Jeong, Seongsu;Howat, Ian M.;Bassis, Jeremy N.
通讯作者：
Bassis, Jeremy N.
影响因子：
18.3
作者：
Greenbaum, J. S.;Blankenship, D. D.;Siegert, M. J.
通讯作者：
Siegert, M. J.
影响因子：
64.8
作者：
Kingslake, Jonathan;Ely, Jeremy C.;Bell, Robin E.
通讯作者：
Bell, Robin E.
影响因子：
18.3
作者：
Jacobs, Stanley S.;Jenkins, Adrian;Dutrieux, Pierre
通讯作者：
Dutrieux, Pierre