I found this over at IO9,maybe it would be of interest :
Meet the Bloop, the mysterious sound from the bottom of the Pacific Ocean
The Bloop is one of about a half-dozen unexplained sounds that the NOAA's Acoustic Monitoring Project has picked up in its more than twenty years listening to the noises of the Pacific. While some of these sounds seem to have relatively obvious explanations, a few really are baffling, and they represent one of science's great unanswered mysteries. Let's now take a closerlisten to the Bloop and five other strange underwater sounds.
Soundclips are in the article
I was wondering if those sounds could have any link to what is happening above, with all the strange sounds heard worldwide but probably they are very distinct phenomenons because they were recorded between 1991 to 1997.