For centuries, coastal dwellers have reported mysterious deep rumbling sounds from the sea, often at night. Now scientists have traced these 'thrums' to humpback whales, revealing a far larger vocal repertoire than previously known.
Fred Sharpe of the Alaska Whale Foundation led a team that set up land-based microphones to capture the sounds. Tips from Alaskan coastal communities helped identify the best recording spots. Alongside known humpback sounds like trumpets and shrieks, the team recorded low-frequency rumbles resembling distant thunder, plus new noises described as 'pizzle', howls and hoots. The thrums travel through air and can be heard up to 10km away.
Sharpe presented the findings at the Astrobiology Science Conference in Wisconsin on 18 May. He suggests the thrums may originate from structures in the whale's blowhole that prevent water entry during dives. Understanding these sounds could help reduce ship strikes and inform the search for extraterrestrial life by overcoming perceptual biases.
