Surf’s up more than 2 miles under the sea, where ice-cold waves as tall as skyscrapers tumble over an underwater “waterfall.”
Yet the ocean surface is calm, and a tropical sun bakes scientists aboard a research ship moored between South America and Africa just south of the equator. Without the network of sensors dangling below, no one would ever know of the tremendous currents rushing through a narrow mountain pass on the seafloor.