Simulating the Wenchuan Earthquake with Accurate Surface Topography on Sunway TaihuLight
Bingwei Chen, Haohuan Fu, Yanwen Wei, Conghui He, Wenqiang Zhang, Yuxuan Li, Wubin Wan, Wei Zhang, Lin Gan, Wei Zhang, Zhenguo Zhang, Guangwen Yang, Xiaofei Chen · 2018
This paper reports our efforts on performing a 50-m resolution earthquake simulation of the Wenchuan Earthquake (Ms 8.0, China) on Sunway TaihuLight. To accurately capture the surface topography, we adopt a curvilinear grid finite-difference method with a traction image free surface implementation and redesign the algorithm to reduce memory access costs for heterogeneous many-core architectures. We then derive a performance model of our algorithm to guide and drive the further optimization and tuning of various parameters using a genetic algorithm. A data layout transformation is also proposed to improve the direct memory access (DMA) efficiency further. Our efforts improve the simulation efficiency from 0.05% to 7.6%, with a sustained performance of 9.07 Pflops using the entire machine of the Sunway TaihuLight (over 10 million cores), and a large-scale simulation of the Wenchuan earthquake with accurate surface topography and improved coda wave effects.