Searched for: subject%3A%22Glacial%255C+isostatic%255C+adjustment%22
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Bouma, Quinten (author)
This thesis introduces a new approach to Glacial Isostatic Adjustment (GIA) modeling using Machine Learning (ML) techniques. The work addresses two main challenges – uncertainty in historical ice load history and the complexity of inverse problems – by developing two ML-based surrogate models (emulators) to rapidly estimate Relative Sea-Level ...
master thesis 2023
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Weerdesteijn, Maaike F.M. (author), Naliboff, John B. (author), Conrad, Clinton P. (author), Reusen, J.M. (author), Steffen, Rebekka (author), Heister, Timo (author), Zhang, Jiaqi (author)
The redistribution of past and present ice and ocean loading on Earth's surface causes solid Earth deformation and geoid changes, known as glacial isostatic adjustment. The deformation is controlled by elastic and viscous material parameters, which are inhomogeneous in the Earth. We present a new viscoelastic solid Earth deformation model in...
journal article 2023
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Kempenaar, Gydo (author)
Uncertainty in ice sheet modelling affects centennial and longer time-scale projections of the Greenland Ice Sheet's (GrIS) sea level contribution. One source of this uncertainty is the interaction between the ice sheet’s evolution and the Earth’s deformation in response to changes in the applied surface loading as the ice sheet waxes and wanes....
master thesis 2022
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Faure, Nils (author)
Glacial Isostatic Adjustment (GIA) is a process which focuses on the deformations of the Earth due to changing ice sheets. It is an important study in Climate Sciences, gravimetric studies and Earth modelling. Studying GIA allows to contribute to a better understanding of the Earth’s composition, thanks to the testing of multiple Earth models,...
master thesis 2022
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Simon, K.M. (author), Riva, R.E.M. (author), Broerse, D.B.T. (author)
In this study, we examine the effect of transient mantle creep on the prediction of glacial isostatic adjustment (GIA) signals. Specifically, we compare predictions of relative sea level (RSL) change from GIA from a set of Earth models in which transient creep parameters are varied in a simple Burgers model to a reference case with a Maxwell...
journal article 2022
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Morra, Fabrizio (author)
The evolution of ice loads during the last Ice Age causes an ongoing Earth response with deformations and stress fields. The viscosity of the mantle depends on stresses, therefore the model stresses should be combined with ambient stresses such as due to mantle convection. This combination has been successfully simulated in the FEM software...
master thesis 2021
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Marsman, C.P. (author), van der Wal, W. (author), Riva, R.E.M. (author), Freymueller, J. T. (author)
In Southeast Alaska, extreme uplift rates are primarily caused by glacial isostatic adjustment (GIA), as a result of ice thickness changes from the Little Ice Age to the present combined with a low-viscosity asthenosphere. Previous GIA models adopted a 1-D Earth structure. However, the actual Earth structure is likely more complex due to the...
journal article 2021
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Marsman, Celine (author)
In Southeast Alaska extreme uplift rates are primarily caused by Glacial Isostatic Adjustment (GIA), as a result of ice load changes from the Little Ice Age to the present combined with a low viscosity asthenosphere. Current GIA models adopt a one-dimensional (1D) stratified Earth structure. The three-dimensional (3D) structure of the Earth is...
master thesis 2020
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van Calcar, Caroline (author)
The Antarctic ice sheet is a complex system highly influenced by global and local processes and characteristics including a varying bedrock elevation and structure of the solid Earth and a changing climate. Sea level rise has a high impact on society and the improvement of forecasts are vital to generate both adaptation and mitigation strategies...
master thesis 2020
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Reusen, J.M. (author), Root, B.C. (author), W. Szwillus, W. (author), Fullea, J. (author), van der Wal, W. (author)
The long‐wavelength negative gravity anomaly over Hudson Bay coincides with the area depressed by the Laurentide Ice Sheet during the Last Glacial Maximum, suggesting that it is, at least partly, caused by glacial isostatic adjustment (GIA). Additional contributions to the static gravity field stem from surface dynamic topography, core‐mantle...
journal article 2020
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Simon, K.M. (author), Riva, R.E.M. (author)
This work provides a comparison of four approaches that can be used to describe uncertainty in models of the long-term glacial isostatic adjustment (GIA) process. The four methods range from pessimistic to optimistic representations of GIA uncertainty. Each estimation method is applied to selected one dimensional GIA model predictions and...
journal article 2020
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Pappa, F. (author), Ebbing, J. (author), Ferraccioli, F. (author), van der Wal, W. (author)
In this study we combine seismological and petrological models with satellite gravity gradient data to obtain the thermal and compositional structure of the Antarctic lithosphere. Our results indicate that Antarctica is largely in isostatic equilibrium, although notable anomalies exist. A new Antarctic Moho depth map is derived that fits the...
journal article 2019
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Vermeulen, Sander (author)
The GRACE mission has provided unprecedented insights into mass redistribution processes in the Earth system. Following a strong call for continuation of the mass observations, the GRACE-Follow On (GRACE-FO) mission was launched in May 2018, leaving a coverage gap of ca. 1 year between GRACE and GRACE-FO. Geopotential solutions derived from data...
master thesis 2019
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van Casteren, Rosalie (author)
The Earth is subjected to 100,000 year cycles of glaciation and deglaciation. The deformations induced by glacial and oceanic loading and the continuous attempt at recovery of the isostatic equilibrium within the solid Earth, are referred to as Glacial Isostatic Adjustment (GIA). This process is ongoing still and yields a large contribution to...
master thesis 2019
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Weerdesteijn, Maaike (author)
The C2,1 and S2,1 spherical harmonic coefficients of glacial isostatic adjustment (GIA) models are dominated by true polar wander (TPW), the secular drift of the position of the Earth’s rotational axis with respect to the Earth’s surface. The Earth’s rotational state and its interior are closely linked. The deformation of the body induced by a...
master thesis 2019
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Hermans, T. H.J. (author), van der Wal, W. (author), Broerse, D.B.T. (author)
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...
journal article 2018
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oude Egbrink, Dirk (author)
Glacial isostatic adjustment is the viscoelastic response of the earth to ice sheet loading. Ice dynamic models employ glacial isostatic adjustment to accurately simulate bedrock uplift. In previous studies, ice dynamic models use only a constant relaxation time to predict bedrock uplift. In this study, the aim is to improve an ice dynamic model...
master thesis 2017
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Hermans, Tim (author)
Glacial isostatic adjustment is the viscoelastic response of the Earth to ice and ocean loads. In forward models of glacial isostatic adjustment, mantle viscosity is often assumed to be laterally homogeneous. However, a lateral transition in shear wave velocities suggests a sharp transition in viscosity between West and East Antarctica. Along...
master thesis 2017
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Sun, Y. (author)
Geocenter motion and changes in the Earth’s dynamic oblateness (J2) are of great importance in many applications. Among others, they are critical indicators of largescale mass redistributions, which is invaluable to understand ongoing global climate change. The revolutionary Gravity Recovery and Climate Experiment (GRACE) satellite mission...
doctoral thesis 2017
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Root, B.C. (author)
In the last decade, the gravity field of the Earth has been observed with increased coverage due to dedicated satellite missions, which resulted in higher resolution and more accurate global gravity field models than were previously available. These models make it possible to study large scale processes such as solid Earth deformation after...
doctoral thesis 2017
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