HR: 10:20h
AN: G32A-01 INVITED    [Abstracts]
TI: Glacial Isostatic Adjustment Signals in Geodetic Data Sets
AU: * Vermeersen, B L
EM: L.L.A.Vermeersen@tudelft.nl
AF: DEOS - TU Delft, Kluyverweg 1, Delft, 2629 HS, Netherlands
AU: Schotman, H H
EM: hugo@deos.tudelft.nl
AF: DEOS - TU Delft, Kluyverweg 1, Delft, 2629 HS, Netherlands
AU: Schotman, H H
EM: hugo@deos.tudelft.nl
AF: SRON, Sorbonnelaan 2, Utrecht, 3584 CA, Netherlands
AU: Riva, R E
EM: R.E.M.Riva@tudelft.nl
AF: DEOS - TU Delft, Kluyverweg 1, Delft, 2629 HS, Netherlands
AU: Gunter, B C
EM: B.C.Gunter@tudelft.nl
AF: DEOS - TU Delft, Kluyverweg 1, Delft, 2629 HS, Netherlands
AU: Lindenbergh, R C
EM: R.C.Lindenbergh@tudelft.nl
AF: DEOS - TU Delft, Kluyverweg 1, Delft, 2629 HS, Netherlands
AB: Present-Day Glacial Isostatic Adjustment (GIA) following melt of the Late-Pleistocene ice sheets is a world-wide phenomenon. Its signals intermingle with those from other geophysical sources in geodetic data sets representing gravity, sea level and rotational variations or crustal deformation. Isolating and consecutively removing the GIA contributions in these data sets in order to obtain estimates on ongoing mass transports, like current melt of continental ice, hydrological variations and sea level change, is far from trivial. Though reasonably accurate GIA estimates exist for global scale purposes, based on simplified earth and Pleistocene ice models and on suitable (mainly Relative Sea Level and GPS) data sets, such estimates might not always have the required accuracy for regional applications. Lateral variations in earth structure, existence of shallow low-viscosity zones in lower crust or asthenosphere in many tectonic provinces, and limited knowledge of the Pleistocene ice sheets are a few examples to illustrate that regional GIA-solutions might have strong, mostly still unknown, deviations from solutions based on global models. This will be illustrated by two regional studies, one on sea level change for Northern Europe and the other for ice mass changes in Antarctica. For example, for Northern Europe the effects of regional shallow low-viscosity crustal and asthenospheric zones will be shown to be of importance for refining European sea level change estimations based on tide gauges, satellite altimetry, gravity and other data sets. In Antarctica, the contribution of GIA to the total mass change has a magnitude comparable to what has been measured by the latest gravity and altimetry satellite missions. As a consequence, ice mass balance estimates are strongly dependent on the assumed Pleistocene ice models and on the local Earth structure.
DE: 1213 Earth's interior: dynamics (1507, 7207, 7208, 8115, 8120)
DE: 1218 Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532)
DE: 1219 Gravity anomalies and Earth structure (0920, 7205, 7240)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1236 Rheology of the lithosphere and mantle (7218, 8160)
SC: Geodesy [G]
MN: 2007 Fall Meeting