[CIG-SHORT] Relax, release!

[Sylvain Barbot]

Greetings,

I am pleased to announce the release of 'Relax', a Fourier-domain code to
simulate quasi-static deformation relevant to short-term tectonics.

Relax can be used to evaluate the displacement and stress in a half space
with gravity due to Okada-type dislocations, Mogi sources, and surface
tractions; and the nonlinear time-dependent deformation that follows due
to power-law rheology materials in the bulk and/or rate-strengthening
friction faults. The numerical method is based on a Fourier-domain elastic
Green's function (Barbot & Fialko, 2010a; 2010b) and an equivalent
body-force representation of co-seismic and post-seismic deformation
processes (Barbot et al., 2009b).

The applications for the earthquake-cycle modeling include: i) co-seismic
displacement and Coulomb stress calculations, ii) quasi-static stress
transfer between earthquakes due to a postseismic transient, iii) modeling
of postseismic transients including lateral variations of rheological
properties, nonlinear constitutive laws and multiple mechanisms, iv) cycle
of multiple earthquakes and spin-up models, v) loading cycle of lakes,
dams or the monsoon.

You can download the source code and binaries from:

http://geodynamics.org/cig/software/relax

Detailed installation instructions for the binary package are in the User
Manual. Detailed building instructions for a few platforms are available
with the source in the INSTALL file.

Many thanks to Louise Kellogg, Brad Aagaard and Charles Williams for
supporting this contribution, and to Walter Landry for packaging the
software for a broader distribution.

Best wishes,

Sylvain Barbot


References:

S. Barbot and Fialko Y., "A Unified Continuum Representation of
Postseismic Relaxation Mechanisms: Semi-Analytic Models of Afterslip,
Poroelastic Rebound and Viscoelastic Flow", GJI, 2010,
http://dx.doi.org/10.1111/j.1365-246X.2010.04678.x

S. Barbot and Fialko Y., "Fourier-Domain Green Function for an Elastic
Semi-Infinite Solid under Gravity, with Applications to Earthquake and
Volcano Deformation", GJI, 2010,
http://dx.doi.org/10.1111/j.1365-246X.2010.04655.x

S. Barbot, Fialko Y., Bock Y., "Postseismic Deformation due to the Mw6.0
2004 Parkfield Earthquake: Stress-Driven Creep on a Fault with Spatially
Variable Rate-and-State Friction Parameters", JGR, 2009,
http://dx.doi.org/10.1029/2008JB005748