Balance velocities and measured properties of the Antarctic ice sheet from a new compilation of gridded data for modeling
This paper presents a new compilation of gridded datasets for three-dimensional modelling of the Antarctic ice sheet. These are for surface elevation, ice thickness, bedrock elevation and accumulation rate as interpolated on a 281 × 281 mesh with 20 km spacing, and encompass all the ice sheet and su...
| Published in: | Annals of Glaciology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2000
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| Subjects: | |
| Online Access: | https://hdl.handle.net/1983/6d150d74-929f-4e2c-8446-6e67b7d6e656 https://research-information.bris.ac.uk/en/publications/6d150d74-929f-4e2c-8446-6e67b7d6e656 https://doi.org/10.3189/172756400781820778 http://bristol.library.ingentaconnect.com/content/igsoc/agl/2000/00000030/00000001/art00010 |
| Summary: | This paper presents a new compilation of gridded datasets for three-dimensional modelling of the Antarctic ice sheet. These are for surface elevation, ice thickness, bedrock elevation and accumulation rate as interpolated on a 281 × 281 mesh with 20 km spacing, and encompass all the ice sheet and surrounding continental shelf. Data sources include the Bamber digital-elevation model from ERS-1 radar-altimeter data, a redigitization of available ice-thickness data, the Giovinetto accumulation data, recent ice-thickness data from British and German expeditions as well as accumulation data from German and Norwegian expeditions. In particular, new data were incorporated for the Filchner-Ronne Ice Shelf and for Dronning Maud Land, Antarctica, arising from the EPICA pre-site survey. Special attention was devoted to matching the various data sources carefully, both among themselves and across the grounding line and below the ice shelves, to enable ice-sheet expansion and retreat in dynamic situations. As an application, the balance flow is calculated over the entire ice sheet using a two-dimensional finite-difference scheme and compared with a previous assessment. This brought to light the existence of ice-streaming features extending well inland. 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, an updated value of 26.4 × 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 removal of the ice sheet and subsequent oceanic invasion and isostatic rebound. The total accumulation over the grounded ice sheet, including the Antarctic Peninsula, is 1924 Gt a−1, or between 5 and 20% higher than earlier estimates. Including all the ice shelves, the value is 2344 Gt a−1. This paper presents a new compilation of gridded datasets for three-dimensional modelling of the Antarctic ice sheet. These are for surface elevation, ice thickness, bedrock ... |
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