Smithsonian.com

Alarmed by the sinking of the Titanic, Reginald Fessenden, a Canadian radio pioneer, began exploring in earnest how a high-frequency oscillator could be used detect icebergs in conditions of low visibility. In 1906, Fessenden had made the first wireless broadcast ever, to United Fruit’s banana boats. By 1914, he had patented an electromechanical oscillator and deployed one, essentially an underwater loudspeaker, in the frigid North Atlantic. In “Sounding Pole to Sea Beam,” Albert E. Theberge writes:

While conducting this experiment, Fessenden, who was quite seasick, and his co-workers, Robert F. Blake and William Gunn, serendipitously noted an echo that returned about two seconds after the outgoing pulse. This turned out to be a return from the bottom. “Thus, on just one cruise…. Fessenden demonstrated that both horizontal and vertical echoes could be generated within the sea.”

The breakthrough in echo-location technology proved useful on passenger ships. During World War I and World War II, fathometers and sonar helped detect submarines. Oceanographers used the technology to map to ocean floor.

The accelerated application of underwater acoustics—enlivened by the Titanic disaster—also birthed another profound change in the ocean: the ability to easily locate fish. “As the 1950s Gorton’s advertisement put it,” Mark Kurlansky writes in Cod, “‘Thanks to these methods, fishing is no longer the hit-or-miss proposition.’” And fish stocks have never been the same.

Image: “The United States Revenue Cutter MIAMI close to an iceberg similar to that which destroyed the TITANIC,” from Scientific American, 1915/NOAA.