Skip to Main Content
Book Chapter

Three-Dimensional Inversion for Large-Scale Structure in a Spherical Domain

By
Adam Schultz
Adam Schultz
Search for other works by this author on:
Geoffrey Pritchard
Geoffrey Pritchard
Institute of Theoretical Geophysics, University of Cambridge, Cambridge CB2 3EQ, UK.
Search for other works by this author on:
Published:
January 01, 1999

Summary

Our inversion method for global conductivity structures uses a forward solver that can represent arbitrary conductivity distributions in a sphere. The inversion uses new methods of grid generation and integration on a convex hull in spherical domains and exploits the relatively high speed and modest memory requirements of the spherical basis expansion. The method reduces the forward problem to the solution of a set of stiff ordinary differential equations, which are solved by finite differences on an adaptive grid. The model is parameterized by a set of regional 1-D models, which then are interpolated into a fully 3-D spherical model using a Delaunay triangulation.

The inversion proceeds in two stages: the first is a nonlinear search in which parameters are varied sequentially to minimize the cost function; the second uses a linearized inversion about the model obtained in the first stage. We have used this method to invert data at 16 frequencies from 20 geomagnetic observatories around the world. The 3-D model is generated from radial profiles (five layers) at 56 locations on the globe.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

Geophysical Developments Series

Three-Dimensional Electromagnetics

Society of Exploration Geophysicists
Volume
7
ISBN electronic:
9781560802154
Publication date:
January 01, 1999

GeoRef

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now