Ability of 1-Hz GPS data to infer the source process of a medium-sized earthquake: The case of the 2008 Iwate-Miyagi Nairiku, Japan, earthquake

[1] We demonstrate the ability of 1-Hz Global Positioning System (GPS) data to infer a medium-sized (M6 class) earthquake source process through an inversion study of the 2008 Iwate-Miyagi Nairiku, Japan, earthquake (M∼6.9). 1-Hz GPS waveforms for this earthquake are compared, and show good agreement with strong motion waveforms. Ground motions are well recorded at a sufficient number of GPS stations in and around source region, allowing us to perform waveform inversion using 1-Hz GPS data only. The 1-Hz GPS inversion result shows fairly good agreement with a joint inversion of geodetic and strong motion data, such as the seismic moment (Mw∼6.9), cumulative slip distribution, and rupture propagation. Such agreements demonstrate that 1-Hz GPS is able to infer the dynamic features of the rupture process as well as permanent (or static) slip even for a M6 class medium-sized earthquake.