Horgan_et_al_[2008_GRL].pdf (511.96 kB)
Complex fabric development revealed by englacial seismic reflectivity: Jakobshavn Isbræ, Greenland
journal contribution
posted on 2023-05-18, 13:49 authored by Horgan, HJ, Anandakrishnan, S, Alley, RB, Peters, LE, Tsoflias, GP, Voigt, DE, Winberry, JPHigh-resolution reflection seismic data from Jakobshavn Isbræ, Greenland, reveal complex fabric development. Abundant englacial reflectivity occurs for approximately half the thickness of the ice (the lower half), and disruption of the englacial reflectors occurs in the lower 10–15% of the ice-thickness. These depths correspond to the higher impurity-content, and more easily deformed, ice from the Younger Dryas and Last Glacial Maximum to Stage-3. We conclude that the reflectivity results from contrasting seismic velocities due to changes in the crystal orientation fabric of the ice, and suggest that these fabric changes are caused by variations in impurity loading and subsequent deformation history. These findings emphasize the difference between ice-divide and ice-stream crystal orientation fabrics and have implications for predictive ice sheet modeling.
History
Publication title
Geophysical Research LettersVolume
35Article number
L10501Number
L10501Pagination
1-6ISSN
0094-8276Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright 2008 The American Geophysical UnionRepository Status
- Open