TY - JOUR
T1 - Anatomy of strike-slip fault tsunami genesis
AU - Elbanna, Ahmed
AU - Abdelmeguid, Mohamed
AU - Ma, Xiao
AU - Amlani, Faisal
AU - Bhat, Harsha S.
AU - Synolakis, Costas
AU - Rosakis, Ares J.
N1 - Funding Information:
A.E. was supported by NSF CAREER Award 1753249, and A.J.R. was supported by the Caltech/Mechanical and Civil Engineering Big Ideas Fund and the Caltech Terrestrial Hazard Observation and Reporting Center. This research is part of the Blue Waters sustained-petascale computing project, which is supported by NSF Awards OCI-0725070 and ACI-1238993, the State of Illinois, and, as of December 2019, the National Geospatial-Intelligence Agency. BlueWaters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications. H.S.B. was supported by European Research Council Consolidator Grant PERSISMO a#865411. C.S was supported by NSF Award 1906162, Field Survey of the September 27, 2018, Sulawesi Tsunami.
Funding Information:
ACKNOWLEDGMENTS. A.E. was supported by NSF CAREER Award 1753249, and A.J.R. was supported by the Caltech/Mechanical and Civil Engineering Big Ideas Fund and the Caltech Terrestrial Hazard Observation and Reporting Center. This research is part of the Blue Waters sustained-petascale computing project, which is supported by NSF Awards OCI-0725070 and ACI-1238993, the State of Illinois, and, as of December 2019, the National Geospatial-Intelligence Agency. Blue Waters is a joint effort of the University of Illinois at Urbana–Champaign and its National Center for Supercomputing Applications. H.S.B. was supported by European Research Council Consolidator Grant PERSISMO a#865411. C.S was supported by NSF Award 1906162, Field Survey of the September 27, 2018, Sulawesi Tsunami.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.
PY - 2021/5/11
Y1 - 2021/5/11
N2 - Tsunami generation from earthquake-induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been considered insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis (>1 m), under rather generic conditions. To this end, we developed a computational framework that integrates models for earthquake rupture dynamics with models of tsunami generation and propagation. The three-dimensional time-dependent vertical and horizontal ground motions from spontaneous dynamic rupture models are used to drive boundary motions in the tsunami model. Our results suggest that supershear ruptures propagating along strike-slip faults, traversing narrow and shallow bays, are prime candidates for tsunami generation. We show that dynamic focusing and the large horizontal displacements, characteristic of strike-slip earthquakes on long faults, are critical drivers for the tsunami hazard. These findings point to intrinsic mechanisms for sizable tsunami generation by strike-slip faulting, which do not require complex seismic sources, landslides, or complicated bathymetry. Furthermore, our model identifies three distinct phases in the tsunamic motion, an instantaneous dynamic phase, a lagging coseismic phase, and a postseismic phase, each of which may affect coastal areas differently. We conclude that near-source tsunami hazards and risk from strike-slip faulting need to be re-evaluated.
AB - Tsunami generation from earthquake-induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been considered insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis (>1 m), under rather generic conditions. To this end, we developed a computational framework that integrates models for earthquake rupture dynamics with models of tsunami generation and propagation. The three-dimensional time-dependent vertical and horizontal ground motions from spontaneous dynamic rupture models are used to drive boundary motions in the tsunami model. Our results suggest that supershear ruptures propagating along strike-slip faults, traversing narrow and shallow bays, are prime candidates for tsunami generation. We show that dynamic focusing and the large horizontal displacements, characteristic of strike-slip earthquakes on long faults, are critical drivers for the tsunami hazard. These findings point to intrinsic mechanisms for sizable tsunami generation by strike-slip faulting, which do not require complex seismic sources, landslides, or complicated bathymetry. Furthermore, our model identifies three distinct phases in the tsunamic motion, an instantaneous dynamic phase, a lagging coseismic phase, and a postseismic phase, each of which may affect coastal areas differently. We conclude that near-source tsunami hazards and risk from strike-slip faulting need to be re-evaluated.
KW - Run-up
KW - Strike-slip faults
KW - Supershear ruptures
KW - Tsunamis in bays
KW - Vertical and horizontal bathymetry motions
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U2 - 10.1073/pnas.2025632118
DO - 10.1073/pnas.2025632118
M3 - Article
C2 - 33941671
SN - 0027-8424
VL - 118
JO - Proceedings of the National Academy of Sciences
JF - Proceedings of the National Academy of Sciences
IS - 19
M1 - e2025632118
ER -