TY  - JOUR
AU  - Yagi Yuji, Nakao Atsushi
PY  - 2012//
TI  - Smooth and rapid slip near the Japan Trench during the 2011 Tohoku-oki earthquake revealed by a hybrid back-projection method
T2  - Earth Planet. Sci. Lett.
JO  - Earth and Planetary Science Letters
SP  - 94
EP  - 101
VL  - 355-356
KW  - 2011 Tohoku-oki earthquake
KW  - back-projection
KW  - seismic source process
KW  - smooth and rapid slip near trench
KW  -
N2  - We developed a new back-projection method that uses teleseismic P-waveforms to integrate the direct P-phase with reflected phases from structural discontinuities near the source and used it to estimate the spatiotemporal distribution of the seismic energy release of the 2011 Tohoku-oki earthquake. We projected a normalized cross-correlation of observed waveforms with corresponding Green's functions onto the seismic source region to obtain a high-resolution image of the seismic energy release. Applying this method to teleseismic P-waveform data of the 2011 Tohoku-oki earthquake, we obtained spatiotemporal distributions of seismic energy release for two frequency bands, a low-frequency dataset and a high-frequency dataset. We showed that the energy radiated in the dip direction was strongly frequency dependent. The area of major high-frequency seismic radiation extended only downdip from the hypocenter, whereas the area of major low-frequency seismic radiation propagated both downdip and updip from the hypocenter. We detected a large release of seismic energy near the Japan Trench in the area of maximum slip, which was also the source area of the gigantic tsunami, when we used only the low-frequency dataset. The timing of this large seismic energy release corresponded to an episode of smooth and rapid slip near the Japan Trench, and reflects the strong dependence of the seismic energy distribution obtained on the frequency band of the input waveform dataset. The episode of smooth and rapid slip may have been the trigger for a release of roughly all of the accumulated elastic strain in the seismic source region of the 2011 Tohoku-oki earthquake.
SN  - 0012-821X
UR  - http://dx.doi.org/10.1016/j.epsl.2012.08.018
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=4647), last updated on Mon, 01 Jul 2024 21:23:39 +0200
ID  - YagiYuji2012
ER  -