Static grounding lines and dynamic ice streams: Evidence from the Siple Coast, West Antarctica
Static grounding lines and dynamic ice streams: Evidence from the Siple Coast, West Antarctica
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DOI：
10.1029/2006gl027091
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发表时间：
2006-09-22
影响因子：
5.2
通讯作者：
Anandakrishnan, S.
中科院分区：
文献类型：
--
作者：
Horgan, H. J.;Anandakrishnan, S.
接地线动力学是我们了解海洋冰盖（例如南极西部冰盖（WAIS））的关键。我们提出了一种使用 GLAS ICESat 激光测高数据准确快速定位接地线的方法。然后，我们将这项技术应用到 WAIS 的 Siple Coast 地区。我们的技术利用了接地线相对于邻近平坦冰流和冰架的高表面坡度。该技术通过地面观测得到验证。当前接地线与早期测量位置之间的比较表明，西普尔海岸的接地线在过去二十年中基本上是静态的。这很重要，因为冰流在此期间经历了相当大的变化。我们得出的结论是，当接地线保持稳定时，冰流流速可能会发生变化。我们建议接地线可能会突然迁移然后稳定下来，而不是持续后退。
Grounding line dynamics are key to our understanding of marine ice sheets such as the West Antarctic Ice Sheet (WAIS). We present an accurate and rapid method for locating grounding lines using GLAS ICESat laser altimetry data. We then apply this technique to the Siple Coast region of the WAIS. Our technique exploits the high surface slope at the grounding line relative to the adjacent flat ice streams and ice shelf. The technique is validated by ground-based observations. Comparisons between the current grounding line and earlier measured locations demonstrate that the Siple Coast's grounding line has been largely static over the last two decades. This is important as the ice streams have been undergoing considerable variations over this period. We conclude that ice stream flow speeds can vary while the grounding line remains stable. We suggest that grounding lines may migrate abruptly and then stabilize rather than undergoing continuous retreat.