Post-seismic stress relaxation with a linear transient rheology

Valentina Cannelli Valentina Cannelli,Antonio Piersanti Antonio Piersanti,Daniele Melini Daniele Melini

doi:10.4401/ag-4642

Valentina Cannelli Valentina Cannelli, Antonio Piersanti Antonio Piersanti + Show 1 more

Open Access

https://doi.org/10.4401/ag-4642

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Abstract

We performed an analysis of post-seismic stress relaxation, taking into account generalized linear rheologies. We compared the stress field (and its derived functions) obtained with a classical Maxwell rheology with that obtained with a transient Burgers body. From a set of synthetic case studies, we have revealed quantitative and qualitative differences both in relaxation times and in local stress values when a transient rheology is introduced. As a practical application, we modeled the time evolution of the Coulomb failure function following the 2009 L'Aquila earthquake, and we show that a transient rheology can lead to non-monotonic time dependence.

Highlights

Observations of post-seismic crustal deformation have often highlighted two apparently separate regimes for the relaxation behavior of the asthenosphere
For the first time, we consider the effects of the transient Burgers rheology [Yuen and Peltier 1982, Pollitz 2003] in the evaluation of postseismic stress relaxation of a spherical, self-gravitating Earth
A synthetic case study In what follows, we present the results obtained by applying our code to synthetic source mechanisms to evidence the transient effects on the time-dependent postseismic stress field due to a Burgers rheology

Summary

Introduction

Observations of post-seismic crustal deformation have often highlighted two apparently separate regimes for the relaxation behavior of the asthenosphere. For the first time, we consider the effects of the transient Burgers rheology [Yuen and Peltier 1982, Pollitz 2003] in the evaluation of postseismic stress relaxation of a spherical, self-gravitating Earth.

Results

Conclusion