Climate-driven bedrock displacements in Greenland and Antarctica
Abstract
The lengthening time-series of land-based GPS stations positioned in Greenland and Antarctica reflect 3-D bedrock displacements caused by a number of surface forcing phenomena. These include, amongst others, elastic response of solid-Earth to ongoing ice mass loss and long-term viscous deformation of mantle in response to the global deglaciation since the Last Glacial Maximum. Isolating such climate-driven surface loading phenomena that operate over a wide range of timescales is critical towards constraining the models of ice sheet mass balance and glacial isostatic adjustment (GIA). Traditionally, surface loads derived from satellite observations are used to forward model the elastic response of solid-Earth, whose structure and properties are usually defined as in Preliminary Reference Earth Model (PREM), and the remainder is attributed to GIA processes. Recent advancement in seismic imaging has revealed departure in elastic parameters from PREM especially in the upper mantle and crust (e.g., Kennett et al., 1995; Cammarano et al., 2005). The regional crustal structures - that may vary significantly from the PREM's crustal profile - have been compiled with high fidelity (Laske et al., 2013). Here we combine information about solid-Earth structure and its elastic properties to quantify the various associated interpretive uncertainties in employing vertical and horizontal bedrock displacements in Greenland and Antarctica to recover climate related signals. By combining these uncertainties with those associated with surface loads themselves (e.g., altimetry measurements and firn compaction models), we present robust estimates of modern climate-driven bedrock displacements and uncertainties therein.
This work was performed at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a contract with the National Aeronautics and Space Administration and funded through JPL's Strategic Research & Technology Development fund (grant #01-STCR-R.17.235.118). © California Institute of Technology. Government Sponsorship acknowledged.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.G43A..01A
- Keywords:
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- 1211 Non-tectonic deformation;
- GEODESY AND GRAVITYDE: 1217 Time variable gravity;
- GEODESY AND GRAVITYDE: 1218 Mass balance;
- GEODESY AND GRAVITYDE: 1236 Rheology of the lithosphere and mantle;
- GEODESY AND GRAVITY