DynEarthSol v2.0: An Efficient Explicit Lagrangian Solver for Geodynamics, Surface Processes, and Earthquake-Cycle Dynamics

Abstract. DynEarthSol version 2.0 (DES v2.0) provides a scalable two- and three-dimensional geodynamic modeling platform designed for multiphysical simulations across temporal and spatial scales. This release achieves high-performance execution by leveraging heterogeneous CPU-GPU architectures; and maintains computational consistency on unstructured meshes through a deterministic two-stage update algorithm, eliminating race conditions and ensuring bitwise reproducibility. The updated framework further expands physical realism through a staggered two-way coupling with the goSPL landscape evolution model, which we validated by simulating the development of a low-angle normal fault and the associated geomorphic signatures. Additionally, we integrated a Dieterich-Ruina rate-and-state friction formulation into the existing Mohr-Coulomb elastoplastic structure. By resolving state-variable evolution within finite-thickness shear zones, this approach enables the simulation of complex fault behaviors, from stable creep to stick-slip instabilities, with finite-thickness faults. The new friction model was verified against analytical benchmarks and applied to earthquake-cycle applications. DES v2.0 serves as a robust, GPU-accelerated, and unified platform for investigating the coupled system of tectonic deformation, surface processes, and seismic-cycle dynamics.