美国爱荷华州立大学Neal R. Iverson团队近日在研究温带冰的线性粘性流动方面取得新进展。相关论文发表在2025年1月10日出版的《科学》杂志上。

温带冰处于压力融化温度，在晶界处含有液态水，对其变形进行精确建模，对于预测冰盖向海洋的排放，以及与之相关的海平面上升至关重要。

这种模型的核心是格伦流动定律，其中应变率取决于应力的n = 3到4次方。与这种非线性形成鲜明对比的是，研究人员通过大规模剪切变形实验发现，在冰川床附近和冰流边缘，在液态水含量和应力的一般范围内，温带冰是线性粘性的（n≈1.0）。

这种线性可能是由扩散压力在晶界融化和再冻结引起的，可以帮助稳定模拟的冰盖对收缩引起的应力增加的响应。

附：英文原文

Title: Linear-viscous flow of temperate ice

Author: Collin M. Schohn, Neal R. Iverson, Lucas K. Zoet, Jacob R. Fowler, Natasha Morgan-Witts

Issue&Volume: 2025-01-10

Abstract: Accurately modeling the deformation of temperate glacier ice, which is at its pressure-melting temperature and contains liquid water at grain boundaries, is essential for predicting ice sheet discharge to the ocean and associated sea-level rise. Central to such modeling is Glen’s flow law, in which strain rate depends on stress raised to a power of n = 3 to 4. In sharp contrast to this nonlinearity, we found by conducting large-scale, shear-deformation experiments that temperate ice is linear-viscous (n ≈ 1.0) over common ranges of liquid water content and stress expected near glacier beds and in ice-stream margins. This linearity is likely caused by diffusive pressure melting and refreezing at grain boundaries and could help to stabilize modeled responses of ice sheets to shrinkage-induced stress increases.

DOI: adp7708

Source: https://www.science.org/doi/10.1126/science.adp7708

来源：科学网  小柯机器人