Auxiliary Material for Paper 2011JB008562

Using short-term postseismic displacements to infer the ambient deformation conditions of the upper mantle

Andrew M. Freed 
Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana, USA

Greg Hirth
Geological Sciences, Brown University, Providence, Rhode Island, USA

Mark D. Behn
Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA

Freed, A. M., G. Hirth, and M. D. Behn (2012), Using short-term postseismic displacements to infer the ambient deformation conditions of the upper mantle, J. Geophys. Res., 117, B01409, doi:10.1029/2011JB008562.

Introduction

The auxiliary material contains four figures that provide information on the influence of errors in the assumed coseismic slip distribution on postseismic results of this study as well as the influence of the weighting term in equation (9) on postseismic results.

1. 2011jb008562-fs01.eps 
Figure S1. Variations in calculated coseismic surface displacements between our nominal coseismic model and ones that have 20% and 40% noise superimposed on the slip distribution. Results show that only coseismic displacements at near-field stations are significantly influenced by the noise.

2. 2011jb008562-fs02.eps 
Figure S2. Variations in calculated coseismic stress shown on a cutaway view the model along the Hector Mine earthquake. (a) Nominal coseismic model, (b) Coseismic model with 20% noise superimposed on the slip distribution. Results show no significant change to the stress field due to the incorporation of 20% noise in the coseismic slip distribution.

3. 2011jb008562-fs03.eps
Figure S3. Variations in calculated postseismic surface displacements (assuming diffusion creep) between models that use our nominal coseismic model and ones that have 20% and 40% noise superimposed on the coseismic slip distribution. The addition of coseismic noise has little influence on calculated postseismic displacements using using the same assumed rheology.

4. 2011jb008562-fs04.eps 
Figure S4. Sensitivity of calculated far-field postseismic displacements to weighting factor (L/150) in the WRRS equations. Shown is a comparison of the best-fitting Newtonian models with and without the weighting factor for a set of far-field stations.