Open AccessThe effects of rheological layering on post‐seismic deformation
Author(s) -
Hetland E. A.,
Hager B. H.
Publication year - 2006
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2006.02974.x
Subject(s) - viscoelasticity , rheology , layering , geology , standard linear solid model , deformation (meteorology) , relaxation (psychology) , mechanics , logarithm , geophysics , geometry , physics , materials science , mathematics , mathematical analysis , composite material , oceanography , botany , biology , psychology , social psychology
SUMMARY We examine the effects of rheological layering on post‐seismic deformation using models of an elastic layer over a viscoelastic layer and a viscoelastic half‐space. We extend a general linear viscoelastic theory we have previously proposed to models with two layers over a half‐space, although we only consider univiscous Maxwell and biviscous Burgers rheologies. In layered viscoelastic models, there are multiple mechanical timescales of post‐seismic deformation; however, not all of these timescales arise as distinct phases of post‐seismic relaxation observed at the surface. The surface displacements in layered models with only univiscous, Maxwell viscoelastic rheologies always exhibit one exponential‐like phase of relaxation. Layered models containing biviscous rheologies may produce multiple phases of relaxation, where the distinctness of the phases depends on the geometry and the contrast in strengths between the layers. Post‐seismic displacements in models with biviscous rheologies can often be described by logarithmic functions.