Abstract
We examined tide gauge records at stations in the Kii Peninsula and western Shikoku to elucidate vertical crustal deformation at and after the 1946 Nankai earthquake as precisely as possible. First, we eliminated effects of atmospheric pressure and astronomical tide from the data of daily mean sea level. Next, we tried to remove influences of oceanic current by taking differences of the corrected data between two stations . Having conducted those data processing, we found that notable crustal deformation followed after the Nankai earthquake and it lasted several years at Uragami and Shimotsu in the Kui Peninsula . The relaxation time of the deformation differs considerably from that observed in Shikoku, which suggests that the post seismic deformation in the Kui Peninsula and that in Shikoku were caused by separate after slips with different relaxation times.
