Strange and inexplicable Pacific sounds

Agency NOAA (National Oceanic and Atmospheric Administration) registered in the depths of the Pacific ocean sounds, the origin of which can not be explained.For over twenty years, scientists have recorded and analyzed noise oceans. They recorded the sounds of seismic activity, sea animals, noise, moving ice masses. However, the origin of some of them to explain still not possible. Various theories have been put forward, which included marine life, the instability of the ice cover, and even UFOs.Sound called "Roar"NOAA detected the sound in 1997, it sounded at ultra-low frequencies and was incredibly powerful. It detected in a very remote area of ​​the Pacific Ocean, which is located to the south-west of South America. Sound character suggests that its source was an animal, but animals are not known to science can produce sounds of this nature, in addition, the volume of the "Roar" is several times higher than any known animal noises. "Roar" was simultaneously recorded several hydrophones, remote from each other for five thousand kilometers, making it the most distant ever heard of ocean sounds.Sound "Julia"It was registered NOAA March 1, 1999, its duration was about fifteen seconds. This noise comes from the equatorial Pacific, the source was somewhere between Easter Island and South America. The sound of "Julia" was also very loud and was recorded by hydrophones, separated by a distance of more than five thousand kilometers.Sound, called "Slow"This zvukNOAA recorded May 19, 1997, it lasted about seven minutes. He was named to slow down, because its height is continuously decreasing over seven minutes. Since 1997, the noise was repeated almost every year, the location of its source identified just north of Easter Island, near the Pacific equator. Scientists have put forward the hypothesis of the origin of the sound "Slow," but it is not confirmed. It sounds like the movement of the Antarctic ice masses, but the location of the source rule out the presence of ice out there at any time of year, so the discussion is still open.Sound, named "Train"This sound was also recorded NOAA in the equatorial Pacific Ocean, just south of Easter Island. At the sound of the dominant regular increase volume and height to fixed limits, echoing train whistles.The sound of "Lifting"It was recorded NOAA in August 1991 and consists of many repetitive sound waves with the rapid rise in frequency. Since the discovery of the sound recorded annually, but the frequency and the volume each time is decreasing. There is a seasonal pattern - the highest frequency sound reaches the spring and fall. Sound source is located in the Pacific Ocean, north of Antarctica, about halfway between New Zealand and South America. Scientists speculate about the nature of the seismic noise and associate it with the appearance of volcanic activity in the region.Sound called "whistle"This sound is detected July 7, 1997, and registered it was only one hydrophone sensor. This is very unusual, as all of the above sounds are captured, at least four different sensors simultaneously. The sound source is located in the equatorial Pacific Ocean, about five hundred miles from Mexico City. The sound resembles that from the whistle and usually lasts about a minute. "Whistle" recorded annually since the discovery.All these unexplained noises come from the depths of the Pacific. One can go to ask, what is their source: the animals, seismic activity, or even a UFO? The good news is that the answer may not take long, becauseNOAA is developing new high-tech hydrophone sensors. Their sensitivity is more than a hundred times greater than the possibility of hydrophones used now.