Which current is a weak, cold, diffuse, slow-moving current at the Eastern boundary, examples include the Canary and Humboldt currents?

Which current is a weak, cold, diffuse, slow-moving current at the Eastern boundary, examples include the Canary and Humboldt currents?

• A. Coastal Upwelling
• B. Contour Current
• C. Antarctic Circumpolar Current
• D. Eastern Boundary Current

Answer: (D)

Eastern boundary currents are the slow, broad, cold flows that run along the eastern edges of subtropical gyres. They are relatively weak and diffuse compared with the fast, narrow western boundary currents, and they bring cold water from higher latitudes toward the equator. The Canary and Humboldt currents are classic examples of this type, hugging the eastern coasts of Africa and South America, respectively, and they exhibit the cool, diffuse, slowly moving character described. Coastal upwelling is a process driven by winds that causes deep water to rise to the surface near coasts, but it isn’t the current itself. Contour currents flow along depth contours in deep water, not along the eastern coastline as a boundary current. The Antarctic Circumpolar Current is a strong, circumglobal current around Antarctica, not an eastern boundary current.

Eastern boundary currents are the slow, broad, cold flows that run along the eastern edges of subtropical gyres. They are relatively weak and diffuse compared with the fast, narrow western boundary currents, and they bring cold water from higher latitudes toward the equator. The Canary and Humboldt currents are classic examples of this type, hugging the eastern coasts of Africa and South America, respectively, and they exhibit the cool, diffuse, slowly moving character described.

Coastal upwelling is a process driven by winds that causes deep water to rise to the surface near coasts, but it isn’t the current itself. Contour currents flow along depth contours in deep water, not along the eastern coastline as a boundary current. The Antarctic Circumpolar Current is a strong, circumglobal current around Antarctica, not an eastern boundary current.