1. Ice fabric in an Antarctic ice stream interpreted from seismic anisotropy
- Author
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Smith, Emma C., Baird, Alan F., Kendall, J. Michael, Martín, Carlos, White, Robert S., Brisbourne, Alex M., and Smith, Andrew M.
- Abstract
Here we present new measurements of an anisotropic ice fabric in a fast moving (377 ma−1) ice stream in West Antarctica. We use ∼6000 measurements of shear wave splitting observed in microseismic signals from the bed of Rutford Ice Stream, to show that in contrast to large‐scale ice flow models, which assume that ice is isotropic, the ice in Rutford Ice Stream is dominated by a previously unobserved type of partial girdle fabric. This fabric has a strong directional contrast in mechanical properties, shearing 9.1 times more easily along the ice flow direction than across flow. This observed fabric is likely to be widespread and representative of fabrics in other ice streams and large glaciers, suggesting it is essential to consider anisotropy in data‐driven models to correctly predict ice loss and future flow in these regions. We show how passive microseismic monitoring can be effectively used to provide these data. Anisotropic ice fabric in an Antarctic ice stream measured using seismic shear wave splittingMeasured fabric results in ice shearing 9.1 times more easily along flow direction than across flowThe measured fabric has strong implications for parametrizing data‐driven models of past and future ice flow
- Published
- 2017
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