GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.3 - POSTER GNGTS 2023 Then, we used a set of LDCs (file REF_6371_loading_love_numbers.txt, distributed with REAR in the DATA/ folder) corresponding to the seismological “REF model” STW105 (Kustowski et al., 2008), which updates the PREM model of Dziewonski and Anderson (1981). We remark that these LDCs have been obtained for a global Earth model, and a more thorough approach should consider the actual regional structure of the lithosphere. After running REAR with these input, we obtained predictions for geodetic observables like the uplift rate, the horizontal rate and the geoid height change (Fig. 2). The figures have been drawn with GMT (Wessel and Smith, 1998). To plot them, a script ready for use, plot_Greenland_maps.gmt5, is available in the folder EXAMPLE/. As we can expect, the highest rates are reached where the mass loss proceeds faster. In the poster, the following topics will be addressed: ● REAR : general functioning and structure. ● Case study 1: Effects of present-day deglaciation in Antarctica and in Greenland in terms of surface displacement, geoid variations and strain, and sensitivity to the elastic layering of the upper mantle. ● Case study 2 : Analysis of the effects of meltwater loading upon geodetic variables assuming a uniform water distribution and comparison with the case of self-gravitating oceans, obtained by solving the sea-level equation. ● Case study 3 : Three-dimensional deformation and gravity changes induced by the water redistribution in reservoirs in response to global warming, with examples from the Italian territory. Acknowledgements REAR includes Fortran code for the evaluation of the Legendre functions from the SHTOOLS package by Wieczorek and Meschede (2018) and the icosahedron pixelization library by Tegmark (1996). REAR is available from https://github.com/danielemelini and it is a free software, released under the GPLv3 license (see http://www.gnu.org/copyleft/gpl.html for details). References Aschwanden, A., Fahnestock, M. A., Truffer, M., Brinkerhoff, D. J., Hock, R., Khroulev, C., & Khan, S. A.; 2019: Contribution of the Greenland Ice Sheet to sea level over the next millennium . Science advances, 5(6), eaav9396. Bevis M., Melini D., and Spada G; 2016: On computing the geoelastic response to a disk load. Geophysical Journal International, 205(1):1804–1812, 2016. doi: 10.1093/gji/ggw115. Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., & Steffen, K.; 2012: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers. The Cryosphere, 6(4), 821-839.