Balance velocities and measured properties of the Antarctic ice sheet from a new compilation of gridded data for modelling
This paper presents a new compilation of gridded data sets for three-dimensional modeling of the Antarctic ice sheet. These are for surface elevation, icethickness, bedrock elevation and accumulation rate as interpolated on a 281 x 281 mesh with 20 km spacing, and encompass all of the ice sheet and...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
2000
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/1479/ https://epic.awi.de/id/eprint/1479/1/Huy9999b.pdf https://hdl.handle.net/10013/epic.12070 https://hdl.handle.net/10013/epic.12070.d001 |
| Summary: | This paper presents a new compilation of gridded data sets for three-dimensional modeling of the Antarctic ice sheet. These are for surface elevation, icethickness, bedrock elevation and accumulation rate as interpolated on a 281 x 281 mesh with 20 km spacing, and encompass all of the ice sheet and thesurrounding continental shelf. Data sources include the Bamber digital elevation model from ERS-1 radar altimeter data, a redigitization of available ice thicknessdata, the Giovinetto accumulation data, recent ice-thickness data from British and German expeditions as well as accumulation data from German and Norwegianexpeditions. In particular, new data were incorporated for the Filchner-Ronne-Schelfeis and for Dronning Maud Land arising from the EPICA pre-site survey.Special attention was devoted to carefully match the various data sources, both among themselves as across the grounding line and below the ice shelves toenable ice-sheet expansion and retreat in dynamic situations. As an application, the balance flow is calculated over the entire ice sheet using a two-dimensionalfinite difference scheme and compared with a previous assessment. This brought to light the existence of ice-streaming features extending well inland of the icesheet. A detailed zoom over Dronning Maud Land exhibits the general flow characteristics of interest for locating a future deep-drilling site. As a by-product, anupdated value of 26.4 x 106 km3 was obtained for the total volume of the ice sheet and ice shelves, or equivalent to 61.1 m of global sea-level rise after removalof the ice sheet and subsequent oceanic invasion and isostatic rebound. The total accumulation over the grounded ice sheet, including the Antarctic Peninsula, is1924 Gta-1, or between 5 and 20% higher than earlier estimates. Including all of the ice shelves, the value is 2344 Gta-1. |
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