Bloop
An ultra-low frequency underwater sound detected by NOAA in 1997, originating from a source larger than any known animal.
Documented record
Known Facts
The Bloop was detected by NOAA's Pacific Marine Environmental Laboratory in 1997.
It was an ultra-low frequency sound originating from the South Pacific.
The sound was much louder than any known animal, including blue whales.
NOAA later concluded the Bloop was likely an icequake — ice calving in Antarctica.
Similar unexplained sounds include Julia, Slow Down, and Train.
Supporting claims & documentation
Evidence For
NOAA Hydrophone Array Data
PRIMARY SOURCEData from NOAA's autonomous hydrophone array in the Pacific.
SOURCE:NOAA / Pacific Marine Environmental Laboratory
Counterpoints & criticisms
Evidence Against
Icequake Explanation
ANALYSISNOAA concluded the Bloop was consistent with ice calving events.
SOURCE:NOAA / Seismological analysis
Unresolved inquiries
Open Questions
Was the Bloop definitively identified as an icequake?
What other unexplained ocean sounds exist?
Could there be unknown large marine animals?
Chronological record
Timeline
Bloop detected by NOAA hydrophone array.
NOAA concludes Bloop was likely an icequake.
Connected dossiers
Related Investigations
References & further reading
Sources
Automatically discovered links
Related Connections
Both involve activities during the 1990s period.
Both involve activities during the 2000s period.
Both involve activities during the 2000s period.