So I was reading cracked as per usual, and today's list is
http://www.cracked.com/article_16871...t-explain.html
So #1 was the "bloop" an unknown sound that was picked up by microphones in ocean 3,000 miles apart. NOAA sped up the recording, and it sounds like something being "dropped" into water.
After listening to it, I noticed there were about 5 more sounds that have been recorded that are unknown.
http://www.pmel.noaa.gov/vents/acous...s_mystery.html
"Julia" and "Train" are probably the strangest.
Thought I would share and add a little "WTF?" to everyone's day.