Parallel Numerical Simulation of Preseismic Deformation in Earthquake-Prone Areas

Abstract

we studied the parallel numerical simulation of preseismic deformation processes in earthquake-prone areas. We developed a parallel algorithm based on a numerical scheme for solving the static elasticity problem using the finite element method. The software implementation uses the Message Passing Interface (MPI) and partitions the computational domain into subdomains, with each process solving a corresponding part of the resulting distributed system of linear algebraic equations. Regression analysis showed that the algorithm has nearly linear time complexity, amounting to O(N1.17). Its memory complexity over the range of meshes with ≈ 105 to ≈ 108 elements was almost strictly linear, at O(N0.985). Statistical analysis of parallel efficiency showed that the optimal number of computational processes was between 6 and 8. Under these conditions, the computation time was approximately 5 min, and the speedup was about 2.9 for a mesh containing 18·107 elements. Parallel efficiency decreased monotonically and fell below 0.3 when more than 9 processes were used. The cost increased almost linearly with the number of processes. The algorithm was therefore not cost-optimal over the considered ranges of mesh sizes and numbers of computational processes.