Japanese sea level records. Two records marked “Japan” are from the citation above. They are averages of long-term records since 1906 (4 sites, blue line), and shorter-term records since 1960 (16 sites, red line). Satellite records (green, 1993-2010) are from the University of Colorado interactive wizard. Wajima records (purple, 1930-2010) are from the PSMSL.
Sea level around Japan rose steadily from 1906 to 1950. Then it dropped for fifteen years and bounced around until 1980. Since then it has risen again, but it is about 20 mm lower than it was in 1950.