Table 1 Characterization of the water masses in the southern Ryukyu Island Arc. *Only one data available
From: Characterization of water masses around the southern Ryukyu Islands based on isotopic compositions
|  | Depth | T (°C) | Salinity | σθ (kg m−3) | δD (‰, average) | δ18O (‰, average) | εNd |
|---|---|---|---|---|---|---|---|
Okinawa Trough side | |||||||
Kuroshio Surface Water | < 100 | 23.4–28.2 | 34.47–34.78 | < 23.0 | 4.5* | 0.5* | − 2.2 |
Kuroshio Tropical Water | 100–200 | 18.6–24.1 | 34.81–34.88 | 23.5–24.6 | 3.6 | 0.4 | − 5.3 to − 5.2 |
Western North Pacific Central Water | 250–500 | 10.0–18.6 | 34.32–34.82 | 25.0–26.4 | 3.1 | 0.4 | − 6.2 to − 2.8 |
Kuroshio Intermediate Water | 500–755 | 5.8–9.0 | 34.29–34.36 | 26.5–27.0 | 1.0 | 0.2 | − 5.1 to − 4.8 |
Deeper Kuroshio Intermediate Water | 755–1900 | 3.6–5.7 | 34.36–34.48 | 27.0–27.5 | 0.4 | 0.0 | − 8.2 to − 4.9 |
Deep water | 1900–1938 | 2.0 | 34.63 | > 27.5 | – | – | – |
Pacific side | |||||||
Surface water | < 83 | 24.5–28.6 | 34.31–34.74 | < 23.0 | 3.3 | 0.4 | − 1.7 to − 1.2 |
North Pacific Tropical Water | 99–216 | 19.3–24.6 | 34.67–34.90 | 23.5–24.7 | 3.4 | 0.4 | − 4.1 to − 1.1 |
Western North Pacific Central Water | 222–476 | 11.2–18.9 | 34.37–34.82 | 24.9–26.0 | 3.1 | 0.4 | − 5.2 to − 3.4 |
North Pacific Intermediate Water | 478–863 | 4.9–11.4 | 34.18–34.39 | 26.3–27.2 | 1.3 | 0.1 | − 7.0 to − 3.8 |
Deeper North Pacific Intermediate Water | 864–1851 | 2.2–4.9 | 34.40–34.61 | 27.2–27.6 | 0.5 | 0.1 | − 4.0 |
Pacific Deep Water | 1907–2620 | 1.7–2.1 | 34.59–34.64 | > 27.7 | 0.7 | 0.0 | − 5.3 |