Colossus (2003): Recorded off the coast of Australia, Colossus is a very loud sound that lasts for several seconds and has yet to be fully explained. Add Comment + Votes ( 2 )
Robert - August 25, 2025TOPColossus is the name given to a powerful, ultra-low-frequency sound detected in 2003 by hydrophones in the Pacific Ocean. Lasting about a minute, its origin remains unverified. The sound's name references its immense acoustic energy. While some speculate it was caused by a massive iceberg scraping the seafloor or a large military exercise, no definitive explanation has been confirmed, leaving it an enigmatic entry in the catalog of ocean sounds.+ Reply ( 1 )Report