Potential of the solid-Earth response for limiting long-term West Antarctic Ice Sheet retreat in a warming climate
Potential of the solid-Earth response for limiting long-term West Antarctic Ice Sheet retreat in a warming climate
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DOI：
10.1016/j.epsl.2015.10.008
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发表时间：
2015-12
影响因子：
5.3
通讯作者：
H. Konrad;I. Sasgen;D. Pollard;V. Klemann
中科院分区：
文献类型：
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作者：
H. Konrad;I. Sasgen;D. Pollard;V. Klemann
我们采用了冰盖动力学和麦克斯韦粘弹性固体地球动力学的耦合模型，包括海平面的重力一致描述。利用这一模式，我们研究了固体地球对南极西部冰盖（WAIS）未来演变的影响。我们从接近南极冰盖现今结构的稳态条件出发，应用不同的大气和海洋强迫以及固体地球流变学来分析西海的退缩。气候强迫是西海崩塌发生的主要控制因素。然而，对于温和的气候强迫和弱的固体地球流变，我们发现相对海平面（RSL）下降与由WAIS撤退引起的粘弹性固体地球响应有关，在几千年的时间尺度上限制了阿蒙森海海湾的撤退，而更坚硬的地球结构在这些条件下产生崩塌。在更强的气候强迫下，与南极西部裂谷系统相关的弱地球结构与南极平均坚硬的固体地球流变学相比，产生了长达5000年的延迟。此外，我们发现，在气候强迫太弱而不能单独迫使WAIS崩溃的情况下，在存在较高软流圈粘度的情况下，格陵兰冰盖假定的快速消冰引起的海平面上升会导致WAIS崩溃。
We employ a coupled model for ice-sheet dynamics and Maxwell viscoelastic solid-Earth dynamics, including a gravitationally consistent description of sea level. With this model, we study the influence of the solid Earth on the future evolution of the West Antarctic Ice Sheet (WAIS). Starting from steady-state conditions close to the present-day configuration of the Antarctic Ice Sheet, we apply different atmospheric and oceanic forcings and solid-Earth rheologies in order to analyse the retreat of the WAIS. Climate forcing is the primary control on the occurrence of WAIS collapse. For moderate climate forcing and weak solid-Earth rheologies, however, we find that the relative sea level (RSL) fall associated with the viscoelastic solid-Earth response due to unloading by WAIS retreat limits the retreat to the Amundsen Sea embayment on time scales of several millennia, whereas stiffer Earth structures yield a collapse under these conditions. Under stronger climate forcing, weak Earth structures associated with the West Antarctic rift system produce a delay of up to 5000 years in comparison to stiffer, Antarctic-average solid-Earth rheologies. Furthermore, we find that sea-level rise from an assumed fast deglaciation of the Greenland Ice Sheet induces WAIS collapse in the presence of higher asthenosphere viscosities in cases when the climatic forcing is too weak to force WAIS collapse alone.