Complex fabric development revealed by englacial seismic reflectivity:: Jakobshavn Isbræ, Greenland

被引：31

作者：

Horgan, H. J. ^{[1
]}

Anandakrishnan, S. ^{[1
]}

Alley, R. B. ^{[1
]}

Peters, L. E. ^{[1
]}

Tsoflias, G. P. ^{[2
]}

Voigt, D. E. ^{[1
]}

Winberry, J. P. ^{[1
]}

机构：

[1] Penn State Univ, Dept Geosci, University Pk, PA 16802 USA

[2] Univ Kansas, Dept Geol, Lawrence, KS 66045 USA

来源：

GEOPHYSICAL RESEARCH LETTERS | 2008年 / 35卷 / 10期

关键词：

D O I：

10.1029/2008GL033712

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

High-resolution reflection seismic data from Jakobshavn Isbr ae, 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.

引用

页数：6

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