Postseismic Deformation Following the April 2016 Kumamoto, Japan, Earthquake Sequence Detected With InSAR

We present postseismic deformation following the Kumamoto, Japan, earthquake sequence in April, 2016 detected with InSAR during ~2 years. We process ALOS- 2/PALSAR-2 and Sentinel-1 SAR images that were acquired right after the mainshock. We detected concentrated deformations along the source faults, Futagawa and Hinagu faults, as well as off-fault deformations. We found LOS displacement consistent with right lateral motion of Futagawa and Hinagu faults, which implies afterslip of causative faults. Displacements locally exceed 10 cm during 2 years. We observe various patterns of temporal evolution of LOC changes. LOS decayed with time constant of about 200 days in a part, while LOS changes accelerated in summer of 2016 in other area. LOS changes also appear to correlate to geology.