Abstract
A source model for generating strong ground motions during the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0) is estimated from a comparison of the observed records of the mainshock and synthetic motions, based on the characterized source model using the empirical Green’s function method. The characterized source model consists of several strong-motion-generation-areas (SMGAs) with high slip velocity superimposed upon the larger rupture area of the earthquake. The final source model has five SMGAs with different sizes, using a trial and error approach. SMGA 1 is located west of the hypocenter in the source region of Southern Sanriku-oki and SMGA 2 in that of the Middle Sanriku-oki, north of the hypocenter. SMGA 3, SMGA 4, and SMGA 5 are located near the down-dip edge of the mainshock source fault, ranging from offshore Miyagi to offshore Ibaraki prefectures. The delay times from the origin time are 15.6 sec at SMGA 1, 66.4 sec at SMGA 2, 68.4 sec at SMGA 3, 109.7 sec at SMGA 4 and 118.2 sec at SMGA 5. The probabilities of earthquake occurrence in these source regions including the five SMGAs have been estimated by the Earthquake Research Committee at less than 7% to 99% with magnitude about 6.9 to 7.5, individually, except the source region of the Middle Sanriku-oki.
Highlights
The 11 March 2011 giant earthquake with Mw 9.0 occurred off the Pacific coast of Tohoku and is the largest historical earthquake to strike in or near Japan
We find that acceleration as well as velocity motions during the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0) are well simulated using a characterized source model consisting of five SMGAs
SMGA 1 is located in the source region of Southern Sanriku-oki west of the hypocenter and SMGA 2 in that of the Middle Sanriku-oki north of the hypocenter
Summary
The 11 March 2011 giant earthquake with Mw 9.0 occurred off the Pacific coast of Tohoku and is the largest historical earthquake to strike in or near Japan. Slip distribution models have been inverted using teleseismic, geodetic, and tsunami data by many researchers (e.g., Fujii and Satake, 2011; Ide et al, 2011; Iinuma et al, 2011; Yagi and Nishimura, 2011; Yamanaka, 2011). We estimate a source model for generating strong ground motions from this earthquake by comparing the observed records from the mainshock with synthesized motions based on a characterized source model and the empirical Green’s function method. The characterized source model consists in several strong-motion-generation-areas (SMGAs) with large slip velocity or high stress drop, distributed across the entire rupture area of the earthquake. The strong motion data at 14 underground stations of KiK-net in near-distance regions ranging from Iwate to Ibaraki prefectures are used to constrain the source modeling (Fig. 4). The observed records used as the empirical Green’s functions are band-pass-filtered from 0.15 Hz to 10 Hz, considering the reliable frequency range of the observed records from the small events
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
