Slow Down (unidentified sound)
Slow Down is a sound recorded on May 19, 1997, in the Equatorial Pacific Ocean by the U.S. National Oceanic and Atmospheric Administration. The source of the sound was most likely a large iceberg as it became grounded.
The name was given because the sound slowly decreases in frequency over about 7 minutes. The sound was detected at . It was recorded using an autonomous hydrophone array. The sound has been picked up several times each year since 1997. One of the hypotheses on the origin of the sound is moving ice in Antarctica. Sound spectrograms of vibrations caused by friction closely resemble the spectrogram of the Slow Down. This suggests the source of the sound could have been caused by the friction between a large ice sheet moving over land.