Towards Scaling Parallel Seismic Raytracing

Marine geologists use seismic tomography techniques to determine the 3D geophysical structure of the ocean floor. At the heart of seismic tomography methods is a forward solver used to compute minimum travel times from all locations in a earth model to sensors used in seismic experiments. The Stingray seismic raytracer was originally based on an adaption of Dijkstra's single-source shortest-path algorithm. Unfortunately, the algorithm's inherent sequential nature limits its scalability. Our new parallel Stingray implementations are based on an iterative data parallel algorithm and demonstrates scalable performance in both time and problem size. Results are presented for OpenMP and MPI experiments on seismic models of significantly larger size than Stingray has processed before.