Acoustic velocity measurements for detecting the crystal orientation fabrics of a temperate ice core ...
The crystal orientation fabric (COF) in ice cores provides detailed information, such as grain size and distribution and the orientation of the crystals in relation to the large-scale glacier flow. These data are relevant for a profound understanding of the dynamics and deformation history of glacie...
| Main Authors: | , , , , , , |
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| Format: | Text |
| Language: | English |
| Published: |
ETH Zurich
2021
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.3929/ethz-b-000499758 http://hdl.handle.net/20.500.11850/499758 |
| Summary: | The crystal orientation fabric (COF) in ice cores provides detailed information, such as grain size and distribution and the orientation of the crystals in relation to the large-scale glacier flow. These data are relevant for a profound understanding of the dynamics and deformation history of glaciers and ice sheets. The intrinsic, mechanical anisotropy of the ice crystals causes an anisotropy of the polycrystalline ice of glaciers and affects the velocity of acoustic waves propagating through the ice. Here, we employ such acoustic waves to obtain the seismic anisotropy of ice core samples and compare the results with calculated acoustic velocities derived from COF analyses. These samples originate from an ice core from Rhonegletscher (Rhone Glacier), a temperate glacier in the Swiss Alps. Point-contact transducers transmit ultrasonic P waves with a dominant frequency of 1 MHz into the ice core samples and measure variations in the travel times of these waves for a set of azimuthal angles. In addition, the ... : The Cryosphere, 15 (7) ... |
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