Utilizing GPS to investigate past ice mass change in the Ross Sea region, Antarctica
Abstract
ANET (Antarctic Network) GPS observations from the Polar Earth Observing Network (POLENET) record solid earth deformation in response to ice mass change. In the Transantarctic Mountains (TAM) region, observed horizontal motions are towards modeled regions of uplift in response to West Antarctic centers of ice mass loss, opposite to the radially outward pattern expected. We investigate alternative ice history and earth structure inputs to GIA models in an attempt to reproduce observed motions in the region. The proximity of the Wilkes Subglacial Basin (WSB), to the west of the TAM, prompts us to investigate the GIA response to evidence-based ice unloading from the WSB region, since ice loss there could produce motion toward West Antarctica at GPS sites located along the TAM. We also explore the impact of centennial-scale ice load change in the Siple Coast region - due to stagnation and reactivation of ice streams - on horizontal motions recorded by ANET in the Ross Sea region. Finally, the majority of our modeling employs radially-varying (1D) earth models, but the influence of laterally heterogeneous mantle viscosity is also investigated by coupling loading scenarios with earth models that permit two different viscosity profiles on either side of a longitudinal boundary bisecting East and West Antarctica. Best fitting ice history and earth models are presented, including preferred upper mantle viscosity values.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.G43B0716K
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHEREDE: 1243 Space geodetic surveys;
- GEODESY AND GRAVITYDE: 1641 Sea level change;
- GLOBAL CHANGEDE: 4928 Global climate models;
- PALEOCEANOGRAPHY