Fig. 1

GNSS observation stations considered in this study. Four stations marked as red squares were used for predicting the time series. Four stations marked as blue squares are used in Figs. 2, 3, and 6, and the stations marked as black squares are the other stations used in this study. Gray area represents land, and a seafloor topographic map is depicted. Gray arrow depicts the horizontal displacement rate observed at the sea bottom after the 2011 Tohoku-Oki earthquake (Honsho et al. 2019). Isodepth contours of the Pacific slab were estimated by Kita et al. (2010), Nakajima and Hasegawa (2006), and Nakajima et al. (2009)