Ice shelf internal reflection horizons reveal past dynamics and oceanic melt
Ice shelves are widely known to slow the transfer of Antarctic grounded ice to the ocean, especially if their flow is decelerated by local pinning points. Their longevity is strongly influenced by the oceanic conditions in the ice shelf cavity. Yet basal melting is poorly constrained by observations...
| Main Authors: | , , , , , , , , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/52426/ https://hdl.handle.net/10013/epic.83c07012-a04c-41e9-999b-82da018d2d4e |
| Summary: | Ice shelves are widely known to slow the transfer of Antarctic grounded ice to the ocean, especially if their flow is decelerated by local pinning points. Their longevity is strongly influenced by the oceanic conditions in the ice shelf cavity. Yet basal melting is poorly constrained by observations and consequently poorly parameterized in models. We map the internal ice stratigraphy with the final goal of using it as a temporal archive of atmospheric, ice-dynamic and, most importantly, oceanic boundary conditions. Here, we start by interpreting data from AWI’s airborne, coherent ultra-wideband radar collected over ice shelves and ice rises in coastal Dronning Maud Land, East Antarctica. We demonstrate examples of traced 3D isochrone surfaces for deducing (i) the accumulation history, (ii) the history of basal melting at the grounding line, and (iii) the evolution of ice dynamic features (e.g., Raymond bumps). This work contributes to international efforts (e.g., SCAR AntArchitecture) of mapping the internal ice stratigraphy across Antarctica. In conjunction with inverse modelling, the internal ice stratigraphy will eventually form an observational baseline to inform numerical models about relevant processes at the ice-shelf base. |
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