Cybershake NZ: Seismic Hazard Analysis using High Performance Computing
presentationposted on 15.05.2019, 04:28 authored by Jason Motha
In the presentation, we describe the computational workflow and results of the June 2018 version (v18.6) of probabilistic seismic hazard analysis (PSHA) in New Zealand based on physics-based ground motion simulations (`Cybershake NZ') and discuss the computational challenges that we hope to tackle together with NeSI and New Zealand HPC community. Cybershake NZ, our NZ adaptation to the original Cybershake workflow developed by the Southern California Earthquake Center (SCEC), is composed of three components: (1) Automated rupture and 3D crustal model generation; (2) Automated ground motion simulation and Intensity Measure calculation, and (3) probabilistic seismic hazard computation. Because of the large number of major seismic sources in NZ, and the need to consider uncertainties in an explicit probabilistic fashion, the total number of simulation realizations is substantial. The latest version of Cybershake contains a total of ~11,000 finite fault simulations and seismic hazard results computed on a spatially-variable grid of ~27,000 stations. QuakeCoRE’s implementation of an earthquake-induced ground motion simulation workflow is based on Graves and Pitarka (2010, 2015), which has been successfully used for investigating many scenarios of past and future earthquakes, and utilizing high performance computing resources provided by NZ eScience Intrastructure (NeSI). The use of HPC and continuous efforts to optimize and automate the workflow have enabled us to complete singular simulations with in a few hours instead of several days. The multi-fold increase in computing capacity due to the recent NeSI’s hardware upgrade has enabled the latest version of Cybershake NZ.