Sökning: "Glacial Isostatic Adjustment GIA"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Glacial Isostatic Adjustment GIA.

  1. 1. Glacial Isostatic Adjustment : Inferences on properties and processes in the upper mantle from 3D dynamical modeling

    Författare :Peter Schmidt; Björn Lund; Christoph Hieronymus; Laust Pedersen; Zdenek Martinec; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Observations of glacial isostatic adjustment (GIA) offers a powerful window into the properties of the Earth's interior. Combined with dynamical modeling of the GIA process we can use the observations to infer properties such as the elastic structure of the lithosphere, the rheology of the mantle and changes in the stress conditions in the Earth. LÄS MER

  3. 2. Contributions of Satellite Geodesy to Post-Glacial Rebound Research

    Författare :Seyed Mehdi Shafiei Joud; Lars E. Sjöberg; Mohammad Bagherbandi; Martin Horwath; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Glacial Isostatic Adjustment GIA ; gravimetric GIA modelling; satellite geodesy; Gravity Recovery And Climate Experiment GRACE ; independent component analysis ICA ; Geodesy and Geoinformatics; Geodesi och geoinformatik;

    Sammanfattning : Glacial Isostatic Adjustment (GIA) is a global and long-term process in the Earth, which began 21.5 millennia ago, according to many ice history modellers. One way to understand the processes of the Earth’s interior, the crustal deformation, and a key correction to estimate the climatological parameters is obtained by studying GIA. LÄS MER

  4. 3. Developments in preconditioned iterative methods with application to glacial isostatic adjustment models

    Författare :Ali Dorostkar; Maya Neytcheva; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : This study examines the block lower-triangular preconditioner with element-wise Schur complement as the lower diagonal block applied on matrices arising from an application in geophysics. The element-wise Schur complement is a special approximation of the exact Schur complement that can be constructed in the finite element framework. LÄS MER

  5. 4. Robust Preconditioners Based on the Finite Element Framework

    Författare :Erik Bängtsson; Maya Neytcheva; Per Lötstedt; Svetozar Margenov; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FEM; iterative solution method; algebraic multilevel preconditioner; sparse approximate inverse; block preconditioner; Schur complement approximation; nonsymmetric saddle point matrix; isostatic glacial adjustment; pre-stress advection; elasticity; viscoelasticity; in compressible solid; ABAQUS; BEM DDM; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Robust preconditioners on block-triangular and block-factorized form for three types of linear systems of two-by-two block form are studied in this thesis. The first type of linear systems, which are dense, arise from a boundary element type of discretization of crack propagation problems. LÄS MER

  7. 5. On modelling of postglacial gravity change

    Författare :Per-Anders Olsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; accurate predictions of the gravity change are important for e.g. reductions of geodetic observations to a reference epoch. During the last decade; Glacial isostatic adjustment GIA is the Earth s response to glacial-induced load variations on its surface. This phenomenon can today be observed in; contribute different and complemental information on the phenomenon. Knowledge of the gravitational component is important for understanding the underlying geodynamical processes. Further; such as vertical and horizontal deformation of the crust; efforts to observe the surface gravity change in Fennoscandia have been intensified and the observational accuracy successively improved. This offers new possibilities at the same time as it puts new demands on modelling. The purpose of this thesis is to study some aspects of the modelling of GIA-induced gravity change; North America and Fennoscandia. Different observables; relative sea level change and disturbances in the gravity field; for example;

    Sammanfattning : Glacial isostatic adjustment (GIA) is the Earth's response to glacial-induced load variations on its surface. This phenomenon can today be observed in, for example, North America and Fennoscandia. LÄS MER