11: Measuring the Flow Through the Kerama Gap

The principal flows in and out of the East China Sea (ECS) are through channels penetrating the Ryukyu Ridge (Figure 1). Since ~20 Sv of Kuroshio mean flow enters and exits through two of these channels, they are especially well known: the East Taiwan Channel (sill depth 775 m) at the ridge’s southwestern end, and the Tokara Strait (sill depth 690 m) near its northeastern end [Choi et al., 2002]. But the deepest channel connecting the ECS to the surrounding ocean is near the ridge mid-point; it is the Kerama Gap, about 50 km wide with sill depth 1050 m [Choi et al., 2002]—see Figure 1.