Diverse landscapes beneath Pine Island Glacier influence ice flow.
Diverse landscapes beneath Pine Island Glacier influence ice flow.
复制标题
DOI：
10.1038/s41467-017-01597-y
复制
发表时间：
2017-11-20
影响因子：
16.6
通讯作者：
Shean DE
中科院分区：
文献类型：
--
作者：
Bingham RG;Vaughan DG;King EC;Davies D;Cornford SL;Smith AM;Arthern RJ;Brisbourne AM;De Rydt J;Graham AGC;Spagnolo M;Marsh OJ;Shean DE
南极西部的松岛冰川（PIG）的退缩，目前对全球海平面上升的贡献约为5-10%。近几十年来，青藏高原的退缩率有所增加，与之相关的冰川变薄向上游迁移，形成了冰川主干的支流。为了预测未来的变化，需要建立模型，包括基础牵引力的可靠参数化，即河床上冰流的阻力。然而，大多数冰盖模型根据卫星获得的地表速度来估计基础摩擦力，而没有先验的关键过程知识，即在冰床界面上的摩擦和形成阻力，以及冰变形以适应床地形而产生的冰流阻力。在这里，我们展示了利用破冰雷达获得的PIG部分地区床地形的高分辨率地图。与目前用于冰盖模型的低分辨率数据相反，这些数据显示了横跨冰盖界面的不同地形。研究表明，这些不同的冰下景观对冰流有影响，并对模拟冰盖演变和预测冰盖损失导致的全球海平面上升提出了挑战。预测南极洲松岛冰川未来的退缩以及对全球海平面的贡献，由于对控制冰基流量的因素把握不到位而受到阻碍。在这里，通过高分辨率的冰雷达成像，作者展示了冰川下不同的景观从根本上影响冰流。
The retreating Pine Island Glacier (PIG), West Antarctica, presently contributes ~5–10% of global sea-level rise. PIG’s retreat rate has increased in recent decades with associated thinning migrating upstream into tributaries feeding the main glacier trunk. To project future change requires modelling that includes robust parameterisation of basal traction, the resistance to ice flow at the bed. However, most ice-sheet models estimate basal traction from satellite-derived surface velocity, without a priori knowledge of the key processes from which it is derived, namely friction at the ice-bed interface and form drag, and the resistance to ice flow that arises as ice deforms to negotiate bed topography. Here, we present high-resolution maps, acquired using ice-penetrating radar, of the bed topography across parts of PIG. Contrary to lower-resolution data currently used for ice-sheet models, these data show a contrasting topography across the ice-bed interface. We show that these diverse subglacial landscapes have an impact on ice flow, and present a challenge for modelling ice-sheet evolution and projecting global sea-level rise from ice-sheet loss. Projecting the future retreat and thus global sea level contributions of Antarctica’s Pine Island Glacier is hampered by a poor grasp of what controls flow at the ice base. Here, via high-resolution ice-radar imaging, the authors show diverse landscapes beneath the glacier fundamentally influence ice flow.
登录
查看更多内容
影响因子：
30.7
作者：
Bamber, J. L.;Aspinall, W. P.
通讯作者：
Aspinall, W. P.
影响因子：
5.2
作者：
Bingham, Robert G.;Siegert, Martin J.
通讯作者：
Siegert, Martin J.
影响因子：
4.9
作者：
Jordan, T. A.;Ferraccioli, F.;Diehl, T. M.
通讯作者：
Diehl, T. M.
影响因子：
5.3
作者：
Karlsson, Nanna B.;Rippin, David M.;Vaughan, David G.
通讯作者：
Vaughan, David G.
影响因子：
30.7
作者：
Favier, L.;Durand, G.;Le Brocq, A. M.
通讯作者：
Le Brocq, A. M.