For several days, bloggers and journalists have been passing arounda news story
[click here]about how the BP oil disaster will unleash a "giant methane bubble" and initiatea mass extinction. Yes, it's a myth. And we've busted it.
In this article, called "Doomsday: How BP Gulf disaster may have triggered a
'world-killing'event,[click here] "a guy named Terrence Aym takes some information he got from a "Mega Disasters" TVspecial on undersea methane bubbles and mixes it with comments about how there are"giant rifts" beneath the sea and an "information blackout." He proposes that a"twenty mile methane bubble" dislodged by the BP oil disaster will erupt from theocean floor, causing tidal waves and giant explosions. The sad part about all thisis that news organizations and blogs took the story seriously.
While it's true that there are methane bubbles (and methane ice) beneath the ocean
floor, they are not about to erupt from Gulf and destroy all life on Earth. This
morning I spoke with two Earth scientists, Dave Valentine of UC Santa Barbara and
Chris Reddy of the Woods Hole Oceanographic Institute, who study methane and oil
seeps from the sea floor. Valentine has just been out to the Gulf to study the
methane levels there, and told io9:
During our recent cruise to the Gulf we observed significantly elevated levels of
methane at water depth greater than 2500 feet, in the vicinity of the Deepwater
Horizon spill site. While the total quantity of methane and other hydrocarbons is
enough to cause problems with the regional ecosystem, there is no plausible scenario
by which this event alone will cause global-scale extinctions.
So yes, there is a methane seep. No, it will not cause tidal waves or explode.
Another fishy fact in the methane bubble doomsday story is Aym's description of
how methane bubbles are what caused the End Permian mass extinction event 250 millionyears ago - a mass extinction that I wrote about recently, here
[click here]. Many scientists do believe that atmospheric changes and ocean anoxia (de-oxygenization)were to blame for that extinction - but even Gregory Ryskin, the scientist whosehighly speculative work is cited in the article, doesn't try to claim this as thesole cause, nor does he believe that one bubble of methane could bring down the
biosphere instantly[click here]. The End Permian extinction took millennia to happen.
So the BP oil spill isn't going to end the world - it's just going to kill a lot
of ocean life. And already-existing methane seeps may be doing slow, deadly damage
to our climate[click here].All this makes it even more obvious that we need to invest in alternate forms ofenergy. But who wants to hear difficult, complicated pieces of information, whenwe could just be screaming about doomsday?
If you'd like to learn more about how methane bubbles really work, here are a few
- Dissolved methane distributions and air-sea flux in the plume of a massive seep field, Coal Oil Point, California[click here]
- Enhanced lifetime of methane bubble streams in the deep ocean [PDF]
- Fate of rising methane bubbles in stratified waters: How much methane reaches the atmosphere [PDF]
- Methane discharge from a deep-sea submarine mud volcano into the upper water column by gas hydrate-coated methane bubbles [PDF]
Or you can indulge in rank speculation.