There is a high concentration of methane gas in the Bermuda Triangle
Scientists have discovered large concentrations of methane gas in the environment of the Bermuda Triangle and have linked it to the decomposing sea organisms trapped on the ocean floor. The methane accumulates as concentrated methane ice waiting to rupture upon contact; if a pocket ruptures, the gas surges up and erupts on the surface without warning.
Aside from the rupture, it could sink a ship as the water beneath the rupture area becomes less dense. This theory began in 1981 when geochemist Richard McIver explained a connection between the two and mentioned that there are methane hydrates in the sediments deep below the ocean floor and a highly concentrated form.