Ice at depth in ice sheets can be softer in bed-parallel shear than Glen's flow law predicts. For example, at Dye 3, Greenland, enhancement factors of3 4 are needed in order to explain the rate of borehole tilting. Previous authors have identified crystal fabric as the dominant contributor, but the role of impurities and crystal size is still incompletely resolved. Here we use two formulations of anisotropic flow laws for ice (Azuma's and Sachs' models) to account for the effects of anisotropy, and show that the measured anisotropy of the ice at Dye 3 cannot explain all the detailed variations in the measured strain rates. The jump in enhancement across the Holocene-\Visconsin boundary is larger than expected from the measured fabrics alone. Dust and soluble-ion concentration divided by crystal size correlates well with the residual enhancement, indicating that most of the "excess deformation" may be due to impurities or crystal size. \Vhile the major features orthe def(Jrrnation at Dye 3 are eXplained by anisotropy and temperature, results also suggest that further research into the role of impurities and crystal size is warranted..
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.