TY - JOUR
T1 - Multi-physics adjoint modeling of Earth structure
T2 - combining gravimetric, seismic, and geodynamic inversions
AU - Reuber, Georg S.
AU - Simons, Frederik J.
N1 - Funding Information:
GSR thanks Frederik Link, Andrea Piccolo, Georg Stadler and Ludovic Raess for helpful discussions, and acknowledges the Universität Mainz, the DFG under grant KA3367/4, the Max-Planck Graduate Center Mainz, and Princeton University for financial support and a pleasant working atmosphere as a Visiting Student Research Collaborator. FJS acknowledges support from the U.S. National Science Foundation under grant EAR-1736046. We would like to thank two anonymous reviewers for their constructive comments.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12
Y1 - 2020/12
N2 - We discuss the resolving power of three geophysical imaging and inversion techniques, and their combination, for the reconstruction of material parameters in the Earth’s subsurface. The governing equations are those of Newton and Poisson for gravitational problems, the acoustic wave equation under Hookean elasticity for seismology, and the geodynamics equations of Stokes for incompressible steady-state flow in the mantle. The observables are the gravitational potential, the seismic displacement, and the surface velocity, all measured at the surface. The inversion parameters of interest are the mass density, the acoustic wave speed, and the viscosity. These systems of partial differential equations and their adjoints were implemented in a single Python code using the finite-element library FeNICS. To investigate the shape of the cost functions, we present a grid search in the parameter space for three end-member geological settings: a falling block, a subduction zone, and a mantle plume. The performance of a gradient-based inversion for each single observable separately, and in combination, is presented. We furthermore investigate the performance of a shape-optimizing inverse method, when the material is known, and an inversion that inverts for the material parameters of an anomaly with known shape.
AB - We discuss the resolving power of three geophysical imaging and inversion techniques, and their combination, for the reconstruction of material parameters in the Earth’s subsurface. The governing equations are those of Newton and Poisson for gravitational problems, the acoustic wave equation under Hookean elasticity for seismology, and the geodynamics equations of Stokes for incompressible steady-state flow in the mantle. The observables are the gravitational potential, the seismic displacement, and the surface velocity, all measured at the surface. The inversion parameters of interest are the mass density, the acoustic wave speed, and the viscosity. These systems of partial differential equations and their adjoints were implemented in a single Python code using the finite-element library FeNICS. To investigate the shape of the cost functions, we present a grid search in the parameter space for three end-member geological settings: a falling block, a subduction zone, and a mantle plume. The performance of a gradient-based inversion for each single observable separately, and in combination, is presented. We furthermore investigate the performance of a shape-optimizing inverse method, when the material is known, and an inversion that inverts for the material parameters of an anomaly with known shape.
KW - Adjoint-state method
KW - Gravitational potential
KW - Multi-physics inversion
KW - Stokes equation
KW - Wave equation
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U2 - 10.1007/s13137-020-00166-8
DO - 10.1007/s13137-020-00166-8
M3 - Article
AN - SCOPUS:85095727293
SN - 1869-2672
VL - 11
JO - GEM - International Journal on Geomathematics
JF - GEM - International Journal on Geomathematics
IS - 1
M1 - 30
ER -