GeoFLAC

May 21, 2026 · View on GitHub

GeoFLAC is a numerical solver for geodynamic modeling, simulating long-term tectonic and lithospheric deformation using a fast Lagrangian analysis of continua (FLAC) method.

🚀 Quick-Start Guide

To get up and running quickly—including compiling the solver, running the standard subduction case, and visualizing the numerical results—please refer to the step-by-step guide:

👉 Quick-Start Guide

📖 Solver Documentation

The doc/ directory contains comprehensive manuals and reference materials for configuring and troubleshooting your simulations:

Quick-Start Guide: Steps to build and run your first model.
Input Parameter Reference: Detailed descriptions of all parameters inside the .inp configuration file.
Troubleshooting Guide: A complete reference of numeric/textual STOP exit codes, common runtime errors, stability limits, and their resolutions.

🛠️ Advanced Compilation Options

While the Quick-Start Guide covers standard compilation, the GeoFLAC Makefile supports several advanced compilation flags when compiling in the src/ directory:

# General usage:
make F90=<f90 compiler> [FLAGS]

Supported Compilers

gfortran — GNU compiler (default, v4.2 or later required for OpenMP support).
ifort — Intel compiler.
pgf90 — PGI compiler (required for compiling GPU acceleration with OpenACC).
f90 — Sun Studio compiler.

Build Flags

debug=1 — Build a debugging binary (enables bounds-checking and detects runtime coding errors).
omp=0 — Disable OpenMP (multi-threaded CPU parallelization).
acc=1 — Enable OpenACC (GPU acceleration).
coverage=1 — Perform code coverage analysis (only supported by gfortran).
gprof=1 — Enable profiling with gprof.

Original author: Eh Tan (June 2020)