Linear-viscous flow of temperate ice

• 成果类型: Article
• 署名作者: Schohn, Collin M.; Iverson, Neal R.; Zoet, Lucas K.; Fowler, Jacob R.; Morgan-Witts, Natasha
• 署名单位: Iowa State University; University of Wisconsin System; University of Wisconsin Madison
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11384
• DOI: 10.1126/science.adp7708
• 发表日期: 2025-01-10
• 页码: 182-185
• 关键词: creep; deformation; rheology

摘要

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 approximate to 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.