Inversion of high-rate (1 sps) GPS data for rupture process of the 11 March 2011 Tohoku earthquake (Mw 9.1)
Article first published online: 8 SEP 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 7, April 2011
How to Cite
2011), Inversion of high-rate (1 sps) GPS data for rupture process of the 11 March 2011 Tohoku earthquake (Mw 9.1), Geophys. Res. Lett., 38, L00G09, doi:10.1029/2011GL048700., and (
- Issue published online: 8 SEP 2011
- Article first published online: 8 SEP 2011
- Manuscript Accepted: 8 AUG 2011
- Manuscript Revised: 5 AUG 2011
- Manuscript Received: 27 JUN 2011
- Tohoku earthquake;
- high-rate GPS;
- source inversion
 The space-time fault displacement history of the 11 March 2011 Tohoku (Mw 9.1) megathrust earthquake is obtained by least-squares inversion of high-rate (1 sample per second) GPS ground motions recorded in Japan. Complete near-source time-varying and static ground motions for periods ≥25 s are fit in the inversion using a normal mode formalism to compute the Green functions. The basic rupture pattern is stable for various choices of model parameters and solution smoothing, and excellent fits to the complete seismo-geodetic ground motions are obtained. The preferred solution has concentrations of slip near the trench and hypocenter, with sub-fault source time function durations of ∼30–70 s and maximum slip of ∼60 m. Down-dip slip spreads over a wider area with smaller maximum slip (<∼10–15 m). Inversion of the high-rate GPS data exploits both the timing and total displacement information in the ground motions, yielding stable estimates of the seismic moment (∼4.8 × 1022 Nm; Mw = 9.1) and slip distribution.