How oceanographers captured a mysterious undersea noise – and the public’s imagination

‘I’m glad there’s still some mysteries out there.’

In 1997, the US National Oceanic and Atmospheric Administration (NOAA) recorded an ultra-low frequency, minute-long sound located 1,500 miles off the coast of Chile. The extraordinarily powerful noise was picked up by underwater hydrophones some 1,800 miles apart, and was eventually deemed to be neither man-made nor attributable to any known deep-sea animal. Nicknamed ‘the Bloop’, this mysterious sound was never heard again, becoming a curiosity for scientists and a springboard for wide-ranging theories for the general public for many years to come. However, following surveys conducted between 2005 and 2010, NOAA scientists determined that the sound was consistent with the rupture of a massive Antarctic ice sheet. In this short documentary from the US director Cara Cusumano, the retired NOAA oceanographer Christopher Fox recalls his experience with ‘the Bloop’, including how it went from a scientific concern to a rare science story that captured the public imagination.