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Seismic observations of a complex firn structure across the Amery Ice Shelf, East Antarctica
Citation
Hollmann, H and Treverrow, A and Peters, LE and Reading, AM and Kulessa, B, Seismic observations of a complex firn structure across the Amery Ice Shelf, East Antarctica, Journal of Glaciology, 67, (265) pp. 777-787. ISSN 0022-1430 (2021) [Refereed Article]
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Copyright Statement
© The Author(s), 2021. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
Abstract
We use seismic refraction data to investigate the firn structure across a suture zone on the Amery
Ice Shelf, East Antarctica, and the possible role of glacier dynamics in firn evolution. In the downstream
direction, the data reveal decreasing compressional-wave velocities and increasing penetration
depth of the propagating wave in the firn layer, consistent with ~1m firn thickening
every 6 km. The boundary between the Lambert Glacier unit to the west and a major suture
zone and the Mawson Escarpment Ice Stream unit to the east, is marked by differences in firn
thicknesses, compressional-wave velocities and seismic anisotropy in the across-flow direction.
The latter does not contradict the presence of a single-maximum crystal orientation fabric
oriented 45–90◦ away from the flow direction. This is consistent with the presence of transverse
simple shear governing the region’s underlying ice flow regime, in association with elevated strain
along the suture zone. The confirmation and quantification of the implied dynamic coupling
between firn and the underlying ice requires integration of future seismic refraction, coring
and modelling studies. Because firn is estimated to cover ~ 98% of the Antarctic continent any
such coupling may have widespread relevance to ice-sheet evolution and flow.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | polar firn, seismics, snow mechanics |
| Research Division: | Earth Sciences |
| Research Group: | Physical geography and environmental geoscience |
| Research Field: | Glaciology |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in the environmental sciences |
| UTAS Author: | Hollmann, H (Mr Hannes Hollmann) |
| UTAS Author: | Treverrow, A (Dr Adam Treverrow) |
| UTAS Author: | Reading, AM (Professor Anya Reading) |
| ID Code: | 147933 |
| Year Published: | 2021 |
| Funding Support: | Australian Research Council (SR140300001) |
| Web of Science® Times Cited: | 3 |
| Deposited By: | Physics |
| Deposited On: | 2021-11-24 |
| Last Modified: | 2022-08-23 |
| Downloads: | 4 View Download Statistics |
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