The Blue View - Methane Bubbles

When we are at sea, there are any number of things to worry about. Storms, freak waves, partially  submerged containers, cranky whales, lightning, ships, pirates, and serious boat malfunctions top the list, and have been the cause of many a lost vessel. We've had a few close calls over the years. We've also had several friends and a number of acquaintances who have lost their boats, and in some cases their lives, from such calamities. Sometimes these things are due to an error in judgment; sometimes the daily routine lulls the crew into a false sense of security and complacency; but often, it is purely bad luck. As if the list wasn't already long enough, I just read of a new menace for mariners to worry about ... the dreaded methane bubbles. When we were parked in Puerto Lucia Marina in La Libertad, Ecuador a few years ago, we were fascinated by all the bubbles that continually percolated their way to the surface of the water. It turns out that there are methane gas and other petroleum deposits just under the earth's surface there, and the methane continually bubbled to the surface. They had built an elaborate catchment system to try to  harvest the gas, but for whatever reason, it hadn't proved viable.

methane bubbles at libertad

While the La Libertad methane bubbles were an interesting, but innocuous, phenomenon, apparently methane bubbles in a much higher quantity could conceivably sink a vessel - even a large ship. It has long been known that large concentrations of frozen methane hydrates exist just below the sediment on the ocean floor. University researchers in both Great Britain and Australia have proposed a theory that portions of these concentrations could break free due to seismic tremors and earthquakes. As it floated towards the water's surface, the methane would change from ice to gas, forming bubbles which would then reduce the buoyancy of the water. If there was enough methane, any vessel caught in the cloud of bubbles would sink within seconds.

methane deposits chart

Proponents suggest that this might be the reason any number of vessels have disappeared without even a distress call. They show, as evidence, the presence of a sunken vessel in the center of a large methane hydrate eruption site in the North Sea.

methane bubbles sink a ship

Critics claim that such eruptions occur only rarely - maybe once every 400 years - and the odds of a ship being in that precise location at the exact time of the eruption are infinitesimally small. On the other hand, I remember reading that the early designers of offshore drilling rigs designed them to withstand a 50 foot wave, because it was estimated such huge rogue waves only occurred somewhere in the world every decade or so, and the odds of any one drilling rig getting clobbered by a wave bigger than that were minute. Now that satellite imagery can track such things, however, it seems there are actually something like 100 rogue waves that size or larger somewhere in the world's oceans at any given time. It's still quite unlikely an oil rig will get hit by such a wave, but the odds are much higher than the designers thought.

As for us, we aren't going to worry too much about the "Ocean Flatulence" theory - it's one of those things we can't do a thing about. If it is a real phenomenon, we can only hope that Neptune enjoys his tot of rum enough to keep us clear of that particular type of night wind.

Note: Despite Marcie's encouragement to the contrary, notice how I avoided incorporating any sophomoric 'fart' humor in this Blue View, like "we have enough flatulence aboard without worrying about Neptune's farts". I am much too sophisticated for that.