Upsweep (unidentified sound)

Upsweep is an unidentified sound detected on NOAA's equatorial autonomous hydrophone arrays. This sound was present when PMEL began recording SOSUS in August, 1991. It consists of a long train of narrow-band upsweeping sounds of several seconds duration each. The source level is high enough to be recorded throughout the Pacific.

The sound appears to be seasonal, generally reaching peaks in spring and fall, but it is unclear whether this is due to changes in the source or seasonal changes in the propagation environment. The source can be roughly located at 54° S 140° W, near the location of inferred volcanic seismicity, but the origin of the sound is unresolved. The overall source level has been declining since 1991 but the sounds can still be detected on NOAA's equatorial autonomous hydrophone arrays.[1]

Some of the other significant unexplained sounds named by NOAA along with Upsweep are Bloop, Julia, Slow Down, Train and Whistle.[2][3][4]

See also

References

  1. ^ One or more of the preceding sentences incorporates text from a publication now in the public domain: ""Upsweep"". National Oceanic and Atmospheric Administration. http://www.pmel.noaa.gov/vents/acoustics/sounds/upsweep.html. Retrieved 2011-08-20. 
  2. ^ "Tuning in to a deep sea monster". CNN. 2002-06-13. http://archives.cnn.com/2002/TECH/science/06/13/bloop/. Retrieved 2010-01-06. 
  3. ^ "Acoustics Monitoring Program". http://www.pmel.noaa.gov/vents/acoustics/specs_all.html. Retrieved 2010-01-06. 
  4. ^ David Wolman (2002-06-15). "Calls from the deep". New Scientist. http://www.science.org.au/nova/newscientist/102ns_001.htm. Retrieved 2010-01-06. 

External links