| Title | Antarctic glacial isostatic adjustment: a new assessment |
| |
| Author | Ivins, E R; James, T S |
| Source | Keynote talks of the XXVII SCAR (Scientific Committee on Antarctic Research) Open Science Conference; by Summerhayes, C (ed.); Antarctic Science vol. 17, no. 4, 2005 p. 541-553, https://doi.org/10.1017/S0954102005002968 |
| Year | 2005 |
| Alt Series | Geological Survey of Canada, Contribution Series 2005127 |
| Publisher | Cambridge University Press (CUP) |
| Meeting | XXVIII SCAR, Scientific Committee on Antarctic Research biennial Science Meeting; Bremen; DE; July 25-31, 2004 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | Nature and Environment |
| Program | Reducing Canada's Vulnerability to Climate Change
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| Released | 2005 11 18 |
| Abstract | The prediction of crustal motions and gravity change driven by glacial isostatic adjustment (GIA) in Antarctica is critically dependent on the reconstruction of the configuration and thickness of the
ice sheet during the Late Pleistocene and Holocene. The collection and analysis of field data to improve the reconstruction has occurred at an accelerated pace during the past decade. At the same time, space-based imaging and altimetry, combined with
on-ice velocity measurements using Global Positioning System (GPS) geodesy, has provided better assessments of the present-day mass balance of the Antarctic ice sheet. Present-day mass change appears to be dominated by deglaciation that is, in large
part, a continuation of late-Holocene evolution. Here a new ice load model is constructed, based on a synthesis of the current constraints on past ice history and present-day mass balance. The load is used to predict GIA crustal motion and geoid
change. Compared to existing glacioisostatic models, the new ice history model is significantly improved in four aspects: (i) the timing of volume losses in the region ranging from the Ross Sea sector to the Antarctic Peninsula, (ii) the maximum ice
heights in parts of the Ellsworth and Transantarctic Mountains, (iii) maximum grounding line position in Pine Island Bay, the Antarctic Peninsula, and in the Ross Sea, (iv) incorporation of present-day net mass balance estimates. The predicted
present-day GIA uplift rates peak at 14 18 mm yr 1 and geoid rates peak at 4 5 mm yr 1 for two contrasting viscosity models. If the asthenosphere underlying West Antarctica has a low viscosity then the predictions could change substantially due to
the extreme sensitivity to recent (past two millennia) ice mass variability. Future observations of crustal motion and gravity change will substantially improve the understanding of sub-Antarctic lithospheric and mantle rheology. |
| GEOSCAN ID | 220806 |
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