A unit of volume transport named in honor of oceanographer Harald U. Sverdrup: 1 million cubic meters of water flowing past a fixed point each second.

• A. Surface Current
• B. Thermohaline Circulation
• C. Sverdrup (sv)
• D. Temperature-salinity (T-S) diagram

Answer: (C)

The main idea here is measuring how much water moves, not how fast it flows. A Sverdrup is a unit used to express volume transport in the ocean: 1 Sverdrup equals 1 million cubic meters of water per second. This unit is named after Harald U. Sverdrup, recognizing his work on wind-driven ocean circulation. Using Sv lets oceanographers compare the total amount of water crossing a boundary, like a section of a current, across different systems. It’s a way to quantify the strength of large-scale flows, rather than describing the type of current or a diagnostic diagram. The other terms describe kinds of currents or tools (surface current, thermohaline circulation, and a temperature–salinity diagram), not a unit of transport.