Structure of ocean circulation between the Galápagos Islands and Ecuador

A significant oceanographic discovery reveals strong cross-hemisphere exchange between the Galápagos Islands and Ecuador, characterized by a robust northeastward surface current transporting 7–11 Sv at depths of 200 m. Underlying this surface flow, a southward undercurrent with a transport of 7–8 Sv was observed, extending up to 600 m deep and 100 km wide. Near the Ecuador coast, the shallow Ecuador Coastal Current extended offshore by 100 km, with peak velocities near 0.33 m/s at the surface, transitioning into the Peru-Chile Countercurrent. The study, conducted using vessel-mounted ADCP measurements from March to April 2009, confirmed these findings through observed sea level differences and their correlation with large-scale climate indices like Niño3 and the Southern Oscillation Index. Notably, more than half of the sea level variability remained unexplained, suggesting complex underlying dynamics.

Collins, C., Mascarenhas, A., & Martinez, R. (2013). Structure of ocean circulation between the Galápagos Islands and Ecuador. Advances in Geosciences, 33, 3–12. https://doi.org/10.5194/adgeo-33-3-2013