Normal mode multiplet coupling on an aspherical, anelastic earth

Abstract

Calculating the singlet eigenfrequencies and eigenfunctions of a non‐rotating, aspherical, anelastic earth model is a computationally intensive procedure, particularly when the number of coupled multiplets incorporated in the basis set is large. Several methods of improving the computational efficiency of this task are developed and tested in this paper. By using a complex‐to‐real basis transformation and making some justifiable approximations, we reduce the original complex symmetric generalized eigenvalue problem for each target multiplet to a real symmetric ordinary eigenvalue problem. In addition, we improve the accuracy of the subspace projection method by extending the analysis to second order in the eigenfunctions and third order in the eigenfrequencies. Copyright © 1992, Wiley Blackwell. All rights reserved