Julia — Iceberg Grounding
The embedded archive audio preserves the historical “Julia” record; interpretation follows NOAA’s current classification.
Record status: “Julia” is no longer best presented as a wholly unexplained anomaly. NOAA now identifies a large Antarctic iceberg grounding on the seafloor as the most likely source.
What NOAA says
The signal was recorded on 1 March 1999 by the eastern equatorial Pacific autonomous hydrophone array. NOAA places the likely source somewhere between the Bransfield Straits and Cape Adare because the arrival azimuth is uncertain.
Archive logic
The interest of Julia is no longer “what monster made the sound?” but how a cryospheric event can propagate through the ocean over enormous distances and initially enter an anomaly catalogue before later classification improves.
Record parameters
| Recorded | 1 March 1999 |
| Array | Eastern Equatorial Pacific |
| Leading source | Large iceberg grounding |
| Playback | NOAA clip speeded up ×16 |