The Bloop (1997): The NOAA Ultra-Low-Frequency Ocean Sound and the Icequake Resolution

In the annals of Fortean phenomena, the “Bloop” remains one of the most enigmatic sounds recorded in the ocean. On July 25, 1997, the U.S. National Oceanic and Atmospheric Administration (NOAA) detected a sound that was so powerful it registered at an ultra-low frequency—far below human hearing range but detectable by hydrophones deep in the waters of the Southern Ocean.

The History and Background

The Bloop is part of a series of mysterious sounds recorded by NOAA between 1997 and 2004. These recordings, collected as part of Project Sound Surveillance System (SOSUS), were intended to monitor submarines but also picked up natural and unknown underwater phenomena. The Bloop, in particular, was notable for its unprecedented intensity and frequency.

Key Events or Sightings

The Bloop’s detection on July 25, 1997, at 06:38 UTC was recorded by hydrophones located off the coast of Antarctica. The sound had a fundamental frequency of around 450 Hz, making it about twice as low as typical whale songs. Its intensity was so high that it appeared to have traveled across thousands of miles of ocean.

Witness Accounts or Evidence

The Bloop’s unique nature led researchers at the time to speculate about its origin. Various theories were proposed, including a large creature such as an unknown species of whale or even extraterrestrial life forms. However, none of these theories could fully explain the sheer scale and frequency of the sound.

Investigations or Research

In 2011, the NOAA published a detailed analysis of the Bloop recordings in their book Oceans of Noise. The research team conducted extensive simulations to understand the possible sources of such a powerful signal. They considered various possibilities, including icequakes (massive shifts and collisions of sea ice), underwater volcanic eruptions, and even unknown biological activity.

The Current Status / Ongoing Mystery

Despite numerous investigations and theories, the true origin of the Bloop remains unknown. While some scientists believe it could be an as-yet-undiscovered creature, others suggest it might have been a massive icequake that occurred in the Southern Ocean. However, no definitive evidence has emerged to support either theory conclusively.

Frequently Asked Questions (5 Q&A pairs)

Q: What exactly is the Bloop?

A: The Bloop is an ultra-low-frequency sound recorded by NOAA hydrophones on July 25, 1997, which was so intense that it registered as a distinct, powerful signal in the ocean.

Q: Why was it named “The Bloop”?

A: The name “Bloop” was given to the sound for confidentiality reasons. It is one of several mysterious underwater noises recorded by Project Sound Surveillance System (SOSUS).

Q: Have any theories been proposed about what caused the Bloop?

A: Various theories have been proposed, including a large unknown creature, an icequake, or even extraterrestrial life forms. However, no definitive explanation has emerged.

Q: What happened after the initial detection of the Bloop?

A: After its initial detection in 1997, the Bloop was extensively analyzed by NOAA researchers. In 2011, a detailed report on the sound was published, providing more information about the recordings and potential sources.

Q: Is there any ongoing research or investigation into the Bloop?

A: While no new definitive evidence has emerged, ongoing research continues to explore the possibility of unknown biological activity or massive icequakes as potential explanations for the Bloop.