Fig. 7

Movement of Tobishima measured by three different techniques. a Displacement of the Tobishima station and the two mainland stations inferred by two astronomical measurements of latitudes and longitudes conducted in 1928 and 1934 (Miyaji 1935). b Displacement of Tobishima by triangulation in 1934 and 1954 (Okuda et al. 1955). c Velocity vectors of the nearby three GNSS stations during 1996–2008 by GNSS (mekira.gsi.go.jp). The location of the maps in a–c is shown with a red square in d. The eastern margin of the Sea of Japan is considered to be a part of the boundary between the Eurasian (Amurian) and the North American (Okhotsk) Plates