Sediment-laden basal ice units near the onset of a fast-flowing glacier in East Antarctica
Understanding the material properties and physical conditions of basal ice is crucial for a comprehensive understanding of Antarctic ice-sheet dynamics. Yet, direct data are sparse and difficult to acquire, necessitating geophysical data for analysis. We employed high-resolution ultra-wideband radar...
| Main Authors: | , , , , , |
|---|---|
| Format: | Conference Object |
| Language: | unknown |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/58688/ https://epic.awi.de/id/eprint/58688/1/EGU24_Sfranke.pdf https://hdl.handle.net/10013/epic.08649525-b095-4978-b97f-d48b3b847e16 |
| Summary: | Understanding the material properties and physical conditions of basal ice is crucial for a comprehensive understanding of Antarctic ice-sheet dynamics. Yet, direct data are sparse and difficult to acquire, necessitating geophysical data for analysis. We employed high-resolution ultra-wideband radar to map high-backscatter zones near the glacier bed within East Antarctica's Jutulstraumen drainage basin. In addition, we used radar forward modelling to constrain their material composition. Our results reveal along-flow oriented sediment-laden basal ice units connected to the basal substrate, extending to several hundred meters thick. Three-dimensional thermomechanical modelling suggests these units initially form via basal freeze-on of subglacial water originating upstream. We suggest that basal freeze-on and the entrainment and transport of subglacial material play a significant role in an accurate representation of the material, physical, and rheological properties of the Antarctic ice sheet's basal ice, ultimately enhancing the accuracy and reliability of ice-sheet modelling. |
|---|