Journal ArticleLinear-viscous flow of temperate iceSchohn, Collin M; Iverson, Neal R; Zoet, Lucas K; Fowler, Jacob R; Morgan-Witts, Natasha<p>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<italic>n</italic>= 3 to 4. In sharp contrast to this nonlinearity, we found by conducting large-scale, shear-deformation experiments that temperate ice is linear-viscous (<italic>n ≈</italic>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.</p>AAAS2025-01-1010598064Science3876730182 to 1850036-8075https://doi.org/10.1126/science.adp77081643120Temperate icelinear-viscous flowice streamsNational Science Foundation