Add Yahoo as a preferred source to see more of our stories on Google. In 1997, NOAA scientists recorded a haunting, strange sound in the southern Pacific Ocean's depths. Theories about the sound's ...

The loudest underwater sound ever recorded has been a mystery for 20 years and it still hasn't got a confirmed explanation. In 1997, the United States' National Oceanic and Atmospheric Administration ...

In 1997, NOAA researchers recorded a mysterious ultra-low-frequency noise so powerful it registered on sensors thousands of miles apart.

In 1997, the National Oceanic and Atmospheric Administration discovered an unusual, ultra-low-frequency sound emanating from a point off the southern coast of Chile. It was the loudest unidentified ...

In the summer of 1997, scientists recorded a strange, loud noise originating from an area west of Chile's southern coast. They dubbed it "the bloop." While searching for underwater volcanoes, ...