Geodynamic simulations in HPC with Python

Abstract—The deformation of the Earth surface reflects the action of several forces that act inside the planet. To understand how the Earth surface evolves complex models must be built to reconcile observations with theoretical numeri-cal simulations. Starting from a well known numerical methodology already used among the geodynamic scientific community, PyGmod has been developed from scratch in the last year. The application simulates 2D large scale geodynamic processes by solving the conservation equations of mass, momentum, and energy by a finite difference method with a marker-in-cell technique. Unlike common simulation code written in Fortran or C this code is written in Python. The code implements a new approach that takes advantage of the hybrid architecture of the latest HPC machines. In PyGmod the standard MPI is coupled with a threading architecture to speed up some critical computations. Since the OpenMP API cannot be used with Python, threading is implemented in Cython. In addition a realtime visualization library has been developed to inspect the evolution of the model during the computation. Index Terms—HPC, numerical modelling, geodynamic