Registered by Sylvain Barbot

The software Relax evaluates the deformation associated with an earthquake cycle including instantaneous coseismic displacements and the postseismic relaxation that follows main shocks. The transient relaxation is due to linear and nonlinear viscoelastic flow and to rate-strengthening friction afterslip. Stress perturbations can be due to surface loads, moving faults, volumetric inclusions, or opening dykes.

The possible applications for the earthquake-cycle modeling include i) co-seismic displacement and Coulomb stress calculation, ii) quasi-static stress transfer between earthquakes due to a postseismic transient, iii) modeling of postseismic transients including nonlinear rheologies and multiple mechanisms, iv) cycle of multiple earthquakes and spin-up models, v) loading cycle of lakes or the monsoon.

The physical model behind the code is described in two articles:

Barbot and Fialko, "A Unified Continuum Representation of Postseismic Relaxation Mechanisms: Semi-Analytic Models of Afterslip, Poroelastic Rebound and Viscoelastic Flow", Geophys. J. Int., 2010,

Barbot and Fialko, "Fourier-Domain Green Function for an Elastic Semi-Infinite Solid under Gravity, with Applications to Earthquake and Volcano Deformation", Geophys. J. Int., 2010,

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Sylvain Barbot
Sylvain Barbot

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trunk series is the current focus of development.

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