Which of these bizarre acoustic phenomena is a real, naturally occurring sound that has been recorded by scientists in the deep ocean?
Correct
The Bloop was a super powerful underwater sound detected by hydrophone arrays in 1997. While it sounds like a massive monster, it was actually the noise of a large icequake as an iceberg cracked and scraped the ocean floor! The Siren is purely a figment of imagination and definitely not how underwater volcanoes behave. Tuna are surprisingly quiet fish and certainly do not sing in harmonic choruses. Giant squid are mysterious, but they do not use bubbles or flute-like whistling to communicate, leaving them without any musical talents.