A deep trough at 31. 3°S, 39. 4°W in the Rio Grande Rise, South Atlantic Ocean, with a depth of 4646 m and a width of approximately 18 km. The Vema Channel acts as a conduit for Weddell Sea Bottom Water and Antarctic Bottom Water (potential temperature below 2°C) between the Argentine and the Brazil Basins, with a mean transport at 4 Sv (4 × 10⁶ m³s⁻¹). Named after the research vessel “Vema” of the former Lamont–Doherty Geological Observatory, Palisades, New York (now Lamont–Doherty Earth Observatory).