日本地球惑星科学連合2022年大会

講演情報

[J] 口頭発表

セッション記号 S (固体地球科学) » S-TT 計測技術・研究手法

[S-TT41] ハイパフォーマンスコンピューティングが拓く固体地球科学の未来

2022年5月22日(日) 09:00 〜 10:30 301A (幕張メッセ国際会議場)

コンビーナ:堀 高峰(独立行政法人海洋研究開発機構・地震津波海域観測研究開発センター)、コンビーナ:八木 勇治(国立大学法人 筑波大学大学院 生命環境系)、汐見 勝彦(国立研究開発法人防災科学技術研究所)、座長:堀 高峰(国立研究開発法人海洋研究開発機構)

09:00 〜 09:15

[STT41-01] 格子H行列を用いた超大規模地震サイクルシミュレーション

★招待講演

*小澤 創1、伊田 明弘2安藤 亮輔3、星野 哲也1 (1.東京大学大学院理学系研究科、2.海洋研究開発機構、3.東京大学情報基盤センター)

キーワード:HPC、境界要素法、地震サイクルシミュレーション

Large-scale earthquake sequence simulations using the boundary element method (BEM) incur extreme computational costs through multiplying a dense matrix with a slip rate vector. Recently, hierarchical matrices (H-matrices) have often been used to accelerate this multiplication. However, the complexity of the structures of the H-matrices and the communication costs between processors limit their scalability, and they therefore cannot be used efficiently in distributed memory computer systems. Lattice H-matrices have recently been proposed as a tool to improve the parallel scalability of H-matrices.

In this study, we develop a method for earthquake sequence simulations applicable to 3D nonplanar faults with lattice H-matrices. We present a simulation example and verify the accuracy of our method for a 3D nonplanar thrust fault. We also performed performance and scalability analyses of our code. Our simulations, using over 100,000 degrees of freedom, demonstrated a parallel acceleration beyond MPI processors and a >10-fold acceleration over the best performance when the normal H-matrices are used. Using this code, we can perform unprecedented large-scale earthquake sequence simulations on geometrically complex faults with supercomputers.