Print Email Facebook Twitter Reversal of the Direction of Horizontal Velocities Induced by GIA as a Function of Mantle Viscosity Title Reversal of the Direction of Horizontal Velocities Induced by GIA as a Function of Mantle Viscosity Author Hermans, T. H.J. (NIOZ Royal Netherlands Institute for Sea Research; Student TU Delft) van der Wal, W. (TU Delft Astrodynamics & Space Missions) Broerse, D.B.T. (TU Delft Physical and Space Geodesy; Universiteit Utrecht) Date 2018-01-01 Abstract In regions undergoing glacial isostatic adjustment present-day horizontal surface motion is observed to point mostly, but not always, away from the former ice load. To interpret these observations, we investigate the direction of horizontal velocities using glacial isostatic adjustment models. The direction is controlled by the opposing actions of inward mantle flow and outward lithosphere motion. In contrast with the prevailing idea that glacial isostatic adjustment-induced horizontal velocities point outward, we show that velocities can be either outward or inward. Immediately after deglaciation velocities point inward but change direction to outward after a time that is controlled by mantle viscosity. Present-day horizontal velocities point outward for a uniform mantle viscosity below 1020 Pa s and inward for above 1022 Pa s, with a combination of outward and inward in between. Our results help to interpret GPS-observed horizontal velocities in areas with varying mantle viscosity. Subject glacial isostatic adjustmenthorizontal velocitiesmantle viscosityreversed direction To reference this document use: http://resolver.tudelft.nl/uuid:36136d9a-cedb-41ab-909d-24ab505336d1 DOI https://doi.org/10.1029/2018GL078533 ISSN 0094-8276 Source Geophysical Research Letters, 45 (18), 9597-9604 Part of collection Institutional Repository Document type journal article Rights © 2018 T. H.J. Hermans, W. van der Wal, D.B.T. Broerse Files PDF Hermans_et_al_2018_Geophy ... etters.pdf 764.49 KB Close viewer /islandora/object/uuid:36136d9a-cedb-41ab-909d-24ab505336d1/datastream/OBJ/view