Seismic wave-propagation simulations are limited in their frequency content by two main factors: (1) the resolution of the seismic wave-speed structure of the region in which the seismic waves are propagated through; and (2) the extent of our understanding of the rupture process, mainly on the short length scales. For this reason, high-frequency content in the ground motion must be simulated through other means. Toward this end, we adopt a variant of the classical empirical Green’s function (EGF) approach of summing, with suitable time shift, recorded seismograms from small earthquakes in the past to generate high-frequency seismograms (0.5–5.0 Hz) for engineering applications. We superimpose these seismograms on low-frequency seismograms, computed from kinematic source models using the spectral element method, to produce broadband seismograms. The non-uniform time-shift scheme used in this work alleviates the over-estimation of high-frequency content of the ground motions observed. We validate the methodology by simulating broadband motions from the 1999 Hector Mine and the 2006 Parkfield earthquakes and comparing them against recorded seismograms.
|Original language||English (US)|
|Number of pages||26|
|State||Published - Aug 27 2020|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-14
Acknowledgements: This research was funded by US National Science Foundation grant number (NSF Award No.0926962). We are grateful to Robert Graves (USGS Pasadena) for reading the draft and providing insightful comments that have significantly enhanced the paper. We thank Chen Ji (UCSB) and Martin Mai (ETHZ, KAUST) for the source models used in this study; Dimitri Komatitsch (University of Pau, France), Jean-Paul Ampuero (Caltech-GPS) and Carl Tape (UAF) for their insights into SPECFEM3D; Thomas Heaton (Caltech) for his insights into Empirical Green’s Function methods. We appreciate the comments by two anonymous peer-reviewers whose comments have enhanced the article.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)