每天数百米的快速浮力驱动的冰盖退缩
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Christine L Batchelor1, Frazer D W Christie2, Dag Ottesen3
1School of Geography, Politics and Sociology, Newcastle University, Newcastle upon Tyne, UK. christine.batchelor@ncl.ac.uk.
Nature
|April 5, 2023
概括
使用海底波纹来量化冰盖接地线的退缩率. 在低梯度的床上出现了快速的退缩脉冲,超过了以前的记录,并突出了浮力驱动的融化的脆弱性.
科学领域:
- 冰川学和海洋地质学
- 古气候学和海平面上升研究
背景情况:
- 对于了解海平面上升至关重要.
- 海底波纹山脊提供了长期的冰盖退缩记录, 但例子很少.
- 现有的数据限制了对未来的退缩动态和海平面上升贡献的理解.
研究的目的:
- 绘制和分析大量的波纹,以量化过去的冰盖退缩率.
- 研究冰床地形与接地线退缩动态之间的关系.
- 评估现代冰盖,特别是南极洲的快速浮力驱动的退缩潜力.
主要方法:
- 使用水度数据识别和绘制超过7600个波纹山脊.
- 分析了挪威中部3万平方公里的山脊距离.
- 在当前气候强迫下应用水静态原理来建模潜在的退缩速率.
主要成果:
- 在最后一次脱冰过程中,记录了接地线快速退缩的脉冲 (55610 m/day).
- 退缩率远远超过之前所有卫星和海洋地质记录.
- 在低梯度 (±1°) 的冰盖床上观察到最高的退缩率,这表明浮力驱动的不接地.
结论:
- 冰盖的平面区域极易受到快速浮力驱动的撤退的影响.
- 挪威架上过去的快速撤退事件为潜在的南极冰盖行为提供了先例.
- 这些发现强调了在未来的海平面上升预测中考虑这些动态的必要性.
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