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

Abstract

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.