Fig. 1
From: Characterization of water masses around the southern Ryukyu Islands based on isotopic compositions
Surface and subsurface current systems in the northwestern Pacific Ocean. Red points represent stations from which Nd isotope data have been reported in previous studies: LM-6/11 (Amakawa et al. 2004b); PA-S-1, PA-S-18, and PA-S-19 (Amakawa et al. 2000); 2, 3, 4, and 5 (Behrens et al. 2018); LS C3a, P2, SCS C5, and WPS N18-05 (Wu 2014). Abbreviations: ECS, East China Sea; KC, Kuroshio Current; KG, Kerama Gap; LS, Luzon Strait; NEC, North Equatorial Current; NPIW, North Pacific Intermediate Water; PDW, Pacific Deep Water; PS, Philippine Sea; RCS, Ryukyu Current System; SCS, South China Sea; TY, Strait between Taiwan and Yonaguni Jima Island; TG, Tokara Gap; UCDW, Upper Circumpolar Deep Water. White points represent stations for which δD values were reported by Horibe and Ogura (1968) (Additional file 5: Fig. S3). The horizontal yellow line in the Luzon Strait indicates a transect studied by Mensah et al. (2014)