Methane Gas in Bermuda Triangle
It is known that large amounts of Methane gas are trapped thousands of feet below the seafloor. If this gas gets released, water density in that area can reduce significantly and the frothy water can no longer provide the buoyancy required to keep a ship afloat.
The Methane Gas theory for disappearances of ships and planes in Bermuda Triangle was not much popular until 1998, when Dr. Ben Clennell of Leeds University England, delivered a lecture at Wales. His main discussion was on Methane gas becoming a big source of future energy. He mentioned that volumes of Methane gas can get released as a result of landslides under the ocean floor. He went on to state that in such an event, the water density in that area and right up to the surface can get so low that it can make a ship drop like a rock. And since the gas is highly combustible, an eruption can also cause a plane flying above it to catch fire and completely get destroyed.
Subsequently through many research it was understood that methane hydrates do exist hundreds of meters below the ocean floor in Bermuda Triangle area in a frozen state at sub zero temperature. Methane gas remain trapped in them. As the hydrates decompose, they start releasing large amount of methane gas creating avalanche like effect (i.e. land slides) in the land layers below the sea floor. The gas once released into the ocean can significantly heat up the water reducing its buoyancy and sinking ships that sail over it. The air also gets so saturated with methane gas that it can create a very turbulent atmosphere which in turn can cause aircraft crashes... this was accepted as a plausible theory. However there is no such definitive evidence yet that such methane effect had actually caused a disappearance.
Here is another Methane theory that I heard directly from a diving veteran of Bermuda at a 2005 conference. This is what he said while talking about ships and planes disappearing in Bermuda Triangle: Methane gas bubbles are formed on the sea floor and gradually they rise to the surface. These gas bubbles are formed below the ocean floor due to dying and decomposing sea organisms. Initially they are very small in size. As they come up, they keep growing in size. These gas bubbles become so big at times that they even get larger than size of a ship as they float right below the surface of the water. When a ship passes over it, the bubble bursts. And the hollowness inside the bubble completely engulfs the ship taking it down into the bottom. Even planes flying overhead could catch fire during such a blowout.
Update October 2014: Recently three large craters have been discovered in Siberia - one in Taymyr peninsula and two in Yamal. The second crater has a diameter of about 15 meters. The scientists and researchers of Trofimuk Institute of Petroleum Gas Geology and Geophysics in Russia tend to believe that these craters have been caused by huge underground explosion which took place as a result of large methane hydrate gas release. This can have a close correlation with Bermuda Triangle ocean area where too such methane hydrates are known to exist below the ocean floor. Such explosions can create large craters under the ocean as well destroying and sucking ships into them.
Well, there are many counter reasons why such Methane gas theory may not actually justify disappearances in Bermuda triangle. Here are those:
1. The largest chunks of Methane reserves are actually found at a distance away from the Bermuda triangle and not really inside the area where most of the disappearances have taken place.
2. Even if Methane gas is to erupt, it has to cross thousands of feet of sediments below the ocean floor and then more than a thousand feet of water in Bermuda Triangle to reach the surface, and then sink a ship. And it has to rise far beyond to burn an aircraft. This itself is a remote possibility. To imagine that a ship or a plane will exactly be there that time, possibility is miniscule.
3. How does it explain the lost ships or planes in Bahamas where water depth is only about 50 feet or so, and where any sunken ship can easily be found.
4. In some occasions, drilling rigs had unknowingly bored into Methane layer under the sea floor and it has been observed that they actually sank slowly due to less dense water. But it was a slow process and they all had enough time to send out messages a number of times. There was never any casualty. Also, in many cases helicopters circling around the area took close pictures of such incidences. And in no case, any helicopter hovering around the area was ever affected.
NOTE: I manually evaluate all posts and include only the ones that are original (not copy pasted from other sources) and having some serious matter.
There has been lab experiments showing that bubbles rising from Methane hydrates can quickly drown sample floating objects because the density of water diminishes significantly resulting in low buoyancy. The eruptions from Methane hydrates can also produce frothy waters that are much lighter in density.
The United States Geological Survey has stated that there is actually large underwater storage of such Methane hydrates worldwide. However, many research work have gone on to record that no such gas release has taken place in large enough quantities in the recent past causing ships or airplanes to sink in Bermuda Triangle.
Ships do cross paths with methane foam rising to the surface as the gas rises for long period of time because of the large amount of the gas in an eruption. You may want to re-evaluate your belief in the "Bermuda Triangle". It's only an area where there is a lot of marine and air travel with accidents and a LOT of embellishment, imagination laced with a lot fantasies. Low flying airplanes do get the effects of methane gas which is lighter than air and tends to rise. The gas can either starve the engine of oxygen or if the engine is very hot it may ignite the gas if it is dense enough. This usually happens at 500 meters or less.