Ye, Lingling and Lay, Thorne and Kanamori, Hiroo (2013) Ground Shaking and Seismic Source Spectra for Large Earthquakes around the Megathrust Fault Offshore of Northeastern Honshu, Japan. Bulletin of the Seismological Society of America, 103 (2B). pp. 1221-1241. ISSN 0037-1106. doi:10.1785/0120120115. https://resolver.caltech.edu/CaltechAUTHORS:20130531-084839156
Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20130531-084839156
Abstract
Large earthquake ruptures on or near the plate boundary megathrust fault offshore of northeastern Honshu, Japan, produce variable levels of regional high‐frequency ground shaking. Analyses of 0.1–10 Hz strong ground motion recordings from K‐NET and KiK‐net stations and 0.3–3.0 Hz short‐period recordings from Hi‐net stations establish that the shaking variations result from a combination of differences in seismic source spectra and path attenuation. Eleven earthquakes with M_w 6.0–7.6 are analyzed, including interplate events at different positions on the megathrust within the rupture zone of the 11 March 2011 Tohoku (M_w 9.0) event and nearby intraplate events within the underthrusting Pacific slab. The relative ground shaking for frequencies of 5–10 Hz is strongest for the 7 April 2011 (M_w 7.2) intraslab event near the coast, followed by intraplate events beneath the outer‐trench slope. Decreasing levels of high‐frequency shaking are produced by interplate megathrust events moving from the down‐dip edge of the seismogenic zone to the up‐dip region near the trench. Differential attenuation measurements from averaged spectral ratios of strong‐motion recordings indicate that average path attenuation is lower for events deeper on the megathrust or within the slab below the coast. Empirical Green’s function analysis isolates the source spectra for the passband 0.3–3.0 Hz, indicating higher corner frequencies for intraplate events and deep megathrust events than for shallow megathrust events. Similar differences in average source spectra are found for teleseismic P waves. Depth‐varying source radiation and path attenuation thus account for the high‐frequency shaking for the 2011 Tohoku mainshock originating from the down‐dip portion of the megathrust.
Item Type: | Article | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Related URLs: |
| |||||||||||||||
ORCID: |
| |||||||||||||||
Additional Information: | © 2013 by the Seismological Society of America. Manuscript received 30 March 2012. This work made use of Generic Mapping Tools (GMT) and Seismic Analysis Code (SAC) software and Federation of Digital Seismic Networks (FDSN) seismic data. The Incorporated Research Institutions for Seismology Data Management System (IRIS-DMS) provided the teleseismic P-wave data, and the F-net, K-NET, KiK-net, and Hi-net data were obtained from the National Research Institute for Earth Science and Disaster Prevention (NIED) data centers. We thank Y. Asano for sharing his catalog of redetermined regional CMT solutions with us. We thank an anonymous reviewer and J. Anderson for thoughtful comments that improved the manuscript. This work was supported by NSF Grant EAR0635570. | |||||||||||||||
Funders: |
| |||||||||||||||
Issue or Number: | 2B | |||||||||||||||
DOI: | 10.1785/0120120115 | |||||||||||||||
Record Number: | CaltechAUTHORS:20130531-084839156 | |||||||||||||||
Persistent URL: | https://resolver.caltech.edu/CaltechAUTHORS:20130531-084839156 | |||||||||||||||
Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||||||||
ID Code: | 38720 | |||||||||||||||
Collection: | CaltechAUTHORS | |||||||||||||||
Deposited By: | Tony Diaz | |||||||||||||||
Deposited On: | 25 Jun 2013 15:15 | |||||||||||||||
Last Modified: | 09 Nov 2021 23:39 |
Repository Staff Only: item control page