Rapid modeling of the 2011 Mw 9.0 Tohoku‐oki earthquake with seismogeodesy

Abstract

AbstractRapid characterization of finite fault geometry and slip for large earthquakes is important for mitigation of seismic and tsunamigenic hazards. Saturation of near‐source weak motion and problematic integration of strong‐motion data into displacements make this difficult in real time. Combining GPS and accelerometer data to estimate seismogeodetic displacement waveforms overcomes these limitations by providing mm‐level three‐dimensional accuracy and improved estimation of coseismic deformation compared to GPS‐only methods. We leverage collocated GPS and accelerometer data from the 2011 Mw 9.0 Tohoku‐oki, Japan earthquake by replaying them in simulated real‐time mode. Using a novel approach to account for fault finiteness, we generate an accurate centroid moment tensor solution independently of any constraint on the slab geometry followed by a finite fault slip model. The replay of GPS and seismic data demonstrates that robust models could have been made available within 3 min of earthquake initiation.