[SSS04-P41] Simultaneous estimation of a long-term and short-term slow slip events in the Bungo Channel region with MCMKF-based inversion
Keywords:Slow slip, Bungo Channel, GNSS
First we pre-processed GNSS time series; we estimate secular velocities, annual and semi-annual variations, coseismic steps and post-seismic deformation based on the least-square method, and subtract them from the original time series.
We employ the plate configuration by Hirose et al. , and select the area of about 200km long to the east and 280km long to the north as the model region. We subdivide it to 719 subfaults, and represent the slip by a series of 24 depleted basis functions. Finally we performed the MCMKF-based inversion to infer cumulative slips and slip velocities. The estimated cumulative slip distribution is consistent with previous studies [e.g. Yoshioka et al., 2015 for the long-term SSE and Nishimura, 2014 for short-term SSEs].
This study may be the first case where both a long-term SSE and short-term SSEs have been estimated simultaneously from GNSS time series.