Toward Exascale Earthquake Ground Motion Simulations for NearFault Engineering Analysis
Abstract
Modernizing SW4 for massively parallel timedomain simulations of earthquake ground motions in 3D earth models increases resolution and provides ground motion estimates for critical infrastructure risk evaluations. Simulations of ground motions from large (M ≥ 7.0) earthquakes require domains on the order of 100 to500 km and spatial granularity on the order of 1 to5 m resulting in hundreds of billions of grid points. Surfacefocused structured mesh refinement (SMR) allows for more constant grid point per wavelength scaling in typical Earth models, where wavespeeds increase with depth. In fact, MR allows for simulations to double the frequency content relative to a fixed grid calculation on a given resource. The authors report improvements to the SW4 algorithm developed while porting the code to the Cori Phase 2 (Intel Xeon Phi) systems at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. As a result, investigations of the performance of the innermost loop of the calculations found that reorganizing the order of operations can improve performance for massive problems.
 Authors:
 Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 Publication Date:
 Research Org.:
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1399737
 Report Number(s):
 LLNLJRNL731165
Journal ID: ISSN 15219615; TRN: US1702849
 Grant/Contract Number:
 AC5207NA27344
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Computing in Science and Engineering
 Additional Journal Information:
 Journal Volume: 19; Journal Issue: 5; Journal ID: ISSN 15219615
 Publisher:
 IEEE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 97 MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; 58 GEOSCIENCES; computational seismology; structural mechanics; earthquake simulations; exascale computing; scientific computing
Citation Formats
Johansen, Hans, Rodgers, Arthur, Petersson, N. Anders, McCallen, David, Sjogreen, Bjorn, and Miah, Mamun. Toward Exascale Earthquake Ground Motion Simulations for NearFault Engineering Analysis. United States: N. p., 2017.
Web. doi:10.1109/MCSE.2017.3421558.
Johansen, Hans, Rodgers, Arthur, Petersson, N. Anders, McCallen, David, Sjogreen, Bjorn, & Miah, Mamun. Toward Exascale Earthquake Ground Motion Simulations for NearFault Engineering Analysis. United States. doi:10.1109/MCSE.2017.3421558.
Johansen, Hans, Rodgers, Arthur, Petersson, N. Anders, McCallen, David, Sjogreen, Bjorn, and Miah, Mamun. 2017.
"Toward Exascale Earthquake Ground Motion Simulations for NearFault Engineering Analysis". United States.
doi:10.1109/MCSE.2017.3421558.
@article{osti_1399737,
title = {Toward Exascale Earthquake Ground Motion Simulations for NearFault Engineering Analysis},
author = {Johansen, Hans and Rodgers, Arthur and Petersson, N. Anders and McCallen, David and Sjogreen, Bjorn and Miah, Mamun},
abstractNote = {Modernizing SW4 for massively parallel timedomain simulations of earthquake ground motions in 3D earth models increases resolution and provides ground motion estimates for critical infrastructure risk evaluations. Simulations of ground motions from large (M ≥ 7.0) earthquakes require domains on the order of 100 to500 km and spatial granularity on the order of 1 to5 m resulting in hundreds of billions of grid points. Surfacefocused structured mesh refinement (SMR) allows for more constant grid point per wavelength scaling in typical Earth models, where wavespeeds increase with depth. In fact, MR allows for simulations to double the frequency content relative to a fixed grid calculation on a given resource. The authors report improvements to the SW4 algorithm developed while porting the code to the Cori Phase 2 (Intel Xeon Phi) systems at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. As a result, investigations of the performance of the innermost loop of the calculations found that reorganizing the order of operations can improve performance for massive problems.},
doi = {10.1109/MCSE.2017.3421558},
journal = {Computing in Science and Engineering},
number = 5,
volume = 19,
place = {United States},
year = 2017,
month = 9
}

Nearfault effects have been widely recognised to produce specific features of earthquake ground motion, that cannot be reliably predicted by 1D seismic wave propagation modelling, used as a standard in engineering applications. These features may have a relevant impact on the structural response, especially in the nonlinear range, that is hard to predict and to be put in a design format, due to the scarcity of significant earthquake records and of reliable numerical simulations. In this contribution a pilot study is presented for the evaluation of seismic groundmotions in the nearfault region, based on a highperformance numerical code for 3Dmore »

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