Print Email Facebook Twitter Simulating horizontal crustal motions of glacial isostatic adjustment using compressible cartesian models Title Simulating horizontal crustal motions of glacial isostatic adjustment using compressible cartesian models Author Reusen, J.M. (TU Delft Astrodynamics & Space Missions) Steffen, R (Lantmäteriet) Steffen, Holger (Lantmäteriet) Root, B.C. (TU Delft Astrodynamics & Space Missions) van der Wal, W. (TU Delft Astrodynamics & Space Missions) Date 2023 Abstract Significant land uplift and horizontal motions have been recorded with Global Navigation Satellite Systems (GNSS) in areas such as Alaska, Iceland and the Northern Antarctic Peninsula (NAP) as a result of Glacial Isostatic Adjustment (GIA) due to ice melt after the Little Ice Age. Here, analysis of horizontal displacement rates can be of extra importance, as they are more sensitive to Earth properties in shallower layers than vertical displacement rates. Proper modelling of horizontal displacement rates with dedicated GIA models requires a spherical Earth with compressible rheology. However, in these small areas, the used GIA models are often incompressible using a Cartesian geometry to ease computation and in some cases allow for lateral viscosity changes or more complex rheology. We investigate the validity of modelled horizontal displacement rates using different approximations, that is using spherical or Cartesian Earth structures, and incompressible, material compressible or compressible rheology. Although the lack of self-gravity and sphericity compensate each other in the vertical, this is less the case for the horizontal. For a disc ice sheet with a radius just over 200 km and a thickness of 1000 m, differences due to sphericity are minimal and the modelled horizontal displacement rates of compressible Cartesian models differ from those simulated by a compressible spherical model by 0.63 mm a-1. Thus, compressible Cartesian GIA models can be applied for modelling horizontal displacement rates of small ice sheets like those in Alaska, Iceland and NAP. Unfortunately, the implementation of compressibility in Abaqus that we use here cannot be extended to spherical models as gravity can not be specified for a spherical body. Other modelling approaches are recommended in such cases. Subject Loading of the EarthGlaciologyMechanicstheory and modellingFinite element method To reference this document use: http://resolver.tudelft.nl/uuid:dc4296a1-d76f-4164-9fca-b64b602d1a6f DOI https://doi.org/10.1093/gji/ggad232 ISSN 0956-540X Source Geophysical Journal International, 235 (1), 542-553 Part of collection Institutional Repository Document type journal article Rights © 2023 J.M. Reusen, R Steffen, Holger Steffen, B.C. Root, W. van der Wal Files PDF ggad232.pdf 1.33 MB Close viewer /islandora/object/uuid:dc4296a1-d76f-4164-9fca-b64b602d1a6f/datastream/OBJ/view