An explanation for some of the disappearances has focused on the presence of vast fields of methane hydrates on the continental shelves. Laboratory experiments carried out in Australia have proven that bubbles can, indeed, sink a scale model ship by decreasing the density of the water any wreckage consequently rising to the surface would be rapidly dispersed by the Gulf Stream. It has been hypothesized that periodic methane eruptions may produce regions of frothy water that are no longer capable of providing adequate buoyancy for ships. If this were the case, such an area forming around a ship could cause it to sink very rapidly and without warning.
Airplanes may also be susceptible to any freak methane releases. Methane also has the ability to cause a piston engine to stall when released into the atmosphere, even at an atmospheric concentration as low as 1%. But although methane is lighter than air, the altimeter of an airplane traveling through it would not, contrary to popular belief, read that the airplane is higher than it really is, causing navigational problems. (Altimeters measure pressure, not the density of air.)