南极冰架易受融水驱动的断裂的影响
Ching-Yao Lai1, Jonathan Kingslake2,3, Martin G Wearing4
1Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA. cylai@ldeo.columbia.edu.
Nature
|August 28, 2020
概括
大气变暖可能导致南极冰架通过水力压裂崩. 一项新的研究显示,如果融化水淹没了60%的支冰架,
科学领域:
- 冰川学
- 气候科学
- 地质学
背景情况:
- 大气变暖增加了地表融化, 通过水力压裂威胁南极冰架.
- 水分裂变会导致冰架崩,加快冰流和海平面上升.
- 南极冰架区域对水裂的脆弱性在很大程度上是未知的.
研究的目的:
- 评估南极冰架支区域对水裂的脆弱性.
- 确定水裂造成不稳定性风险的特定区域.
主要方法:
- 通过卫星图像训练深层卷积神经网络 (DCNN) 来绘制南极冰架上的表面断裂.
- 开发了基于线性弹性断裂力学的断裂稳定图来预测断裂形成.
- 应用断裂力学理论来预测水淹场景下的不稳定性.
主要成果:
- 一个DCNN成功地绘制了骨折, 显示与理论预测的一致.
- 60% ± 10% 的支冰盖的南极冰架如果被水淹没,很容易发生水裂.
- 确定了广泛的脆弱区域,表面融化的增加可能会引发水力压裂.
结论:
- 许多支南极冰架的地区很容易受到水分断裂的影响,尽管目前对融水的抵抗力很强.
- 由于大气变暖而增加的表面融化可能会淹没这些脆弱的地区,
- 这些脆弱地区是气候变化可能对冰盖质量平衡和海平面上升产生重大影响的关键地区.
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