QDYN

A Quasi-DYNamic earthquake simulator

Quickstart | Documentation | Installation | Suggested references

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What is QDYN?

QDYN is a boundary element software to simulate earthquake cycles (seismic and aseismic slip on tectonic faults) under the quasi-dynamic approximation (quasi-static elasticity combined with radiation damping) on faults governed by rate-and-state friction and embedded in elastic media.

QDYN includes various forms of rate-and-state friction and state evolution laws, and handles non-planar fault geometry in 3D and 2D media, as well as spring-block simulations. Loading is controlled by remote displacement, steady creep or oscillatory load. In 3D it handles free surface effects in a half-space, including normal stress coupling. The medium surrounding the fault is linear, isotropic and elastic, and may be uniform or (in 2D) contain a damaged layer.

QDYN implements adaptive time stepping, shared-memory parallelization, and can deal with multi-scale earthquake cycle simulations with fine details in both time and space. It is equipped with user-friendly MATLAB and Python interfaces and graphical output utilities.

Main features

• Rate-and-state friction, with velocity cut-offs, aging and slip laws
• Microphysically based frictional model (Chen-Niemeijer-Spiers model)
• Heterogeneous frictional properties
• Slow and fast, aseismic and seismic slip transients
• Dynamic weakening (thermal pressurization)
• Multiple and non-planar faults (rectangular elements)
• 3D, 2D and 1D (spring-block)
• Tectonic and transient loads
• Normal stress coupling (free surface effects and fault interactions)
• Faults surrounded by damaged zones
• Python wrapper and graphic output display utilities
• Parallelized for shared memory systems (OpenMP)
• Parallelized for distributed memory systems (MPI)

LSODA solver

This fork contains the implementation of LSODA solver from the ODEPACK, Lawrence Livermore National Laboratory.

The solver allows faster time-stepping when integrating the rate-and-state friction ODEs in larger relative tolerance and not loosing the overall model behaviors. The LSODA solver only works for solving rate-and-state friction law.

The CNS friction law and other evolutions like thermal pressurization is not tested in this fork.

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Downloads, documentation and support

Previous (stable) versions of QDYN can be downloaded from the release page. Development versions are available as separate branches following the naming convention release/x.x.x.

Questions, feedback or suggestions can be submitted via our issue tracking system.

Core developers

(listed alphabetically)

Jean-Paul Ampuero (IRD/UCA, Géoazur, France; Caltech Seismolab, USA)

Martijn van den Ende (Université Côte d'Azur, Géoazur, France)

Percy Galvez (KAUST, Saudi Arabia; AECOM, Switzerland)

Benjamin Idini (Caltech Seismolab, USA)

Yingdi Luo (NASA JPL, USA)

Suggested References

For all uses of the QDYN software

Luo, Y., Ampuero, J. P., Galvez, P., van den Ende, M., & Idini, B. (2017). QDYN: a Quasi-DYNamic earthquake simulator (v1.1) [Data set]. Zenodo. doi:10.5281/zenodo.322459

For simulations on heterogeneous faults

Luo, Y., & Ampuero, J. P. (2018). Stability of faults with heterogeneous friction properties and effective normal stress. Tectonophysics, 733, 257-272, doi:10.1016/j.tecto.2017.11.006

Luo, Y., Ampuero, J. P., Miyakoshi, K., & Irikura, K. (2017). Surface rupture effects on earthquake moment-area scaling relations. Pure and Applied Geophysics, 174(9), 3331-3342, doi:10.1007/s00024-017-1467-4. In Topical Volume on "Best Practices in Physics-based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations".
PDF

Luo, Y., & Ampuero, J. P. (2012), Simulation of Complex Tremor Migration Patterns, AGU Fall Meeting 2012 Abstract S44B-02

Luo, Y., & Ampuero, J. P. (2011), Numerical Simulation of Tremor Migration Triggered by Slow Slip and Rapid Tremor Reversals, AGU Fall Meeting 2011, abstract S33C-02

For the microphysically based (CNS) simulations

van den Ende, M. P. A., Chen, J., Ampuero, J. P., & Niemeijer, A. R. (2018). A comparison between rate-and-state friction and microphysical models, based on numerical simulations of fault slip. Tectonophysics, 733, 273-295, doi:10.1016/j.tecto.2017.11.040

For simulations on faults surrounded by damaged zones

Idini, B., & Ampuero, J. P. (2017). Rupture complexity promoted by damaged fault zones in earthquake cycle models. AGU Fall Meeting 2017, abstract T41C-0632.
Poster PDF, doi:10.1002/essoar.10500080.1

For rate-and-state friction simulations including viscosity

Beall, A., van den Ende, M. P. A., Ampuero, J. P., Capitanio, F. A., Fagereng, A. (2022). Linking Earthquake Magnitude‐Frequency Statistics and Stress in Visco‐Frictional Fault Zone Models. Geophysical Research Letters 49(20), doi:10.1029/2022GL099247