Methane clathrate explosion filmed and studied

[Mk]

http://www.ia.ucsb.edu/pa/display.aspx?pkey=1482

Remarkable and unexpected support for this idea occurred when divers and scientists from UC Santa Barbara observed and videotaped a massive blowout of methane from the ocean floor. It happened in an area of gas and oil seepage coming out of small volcanoes in the ocean floor of the Santa Barbara channel—called Shane Seep—near an area known as the Coal Oil Point seep field. The blowout sounded like a freight train, according to the divers.

"Other people have reported this type of methane blowout, but no one has ever checked the numbers until now," said Ira Leifer, lead author and an associate researcher with UCSB's Marine Science Institute. "Ours is the first set of numbers associated with a seep blowout." Leifer was in a research boat on the surface at the time of the blowouts.

Aside from underwater measurements, a nearby meteorological station measured the methane "cloud" that emerged as being approximately 5,000 cubic feet, or equal to the volume of the entire first floor of a two-bedroom house. The research team also had a small plane in place, flown by the California Department of Conservation, shooting video of the event from the air.

Leifer explained that when this type of blowout event occurs, virtually all the gas from the seeps escapes into the atmosphere, unlike the emission of small bubbles from the ocean floor, which partially, or mostly, dissolve in the ocean water. Transporting this methane to the atmosphere affects climate, according to the researchers. The methane blowout that the UCSB team witnessed reached the sea surface 60 feet above in just seven seconds. This was clear because the divers injected green food dye into the rising bubble plume.

Co-author Bruce Luyendyk, professor of marine geophysics and geological sciences, explained that, to understand the significance of this event (which occurred in 2002), the UCSB research team turned to a numerical, bubble-propagation model. With the model, they estimated methane loss to the ocean during the upward travel of the bubble plume.

The results showed that for this shallow seep, loss would have been approximately one percent. Virtually all the methane, 99 percent of it, was transported to the atmosphere from this shallow seep during the blowout. Next, the scientists used the model to estimate methane loss for a similar size blowout at much greater depth, 250 meters. Again, the model results showed that almost all the methane would be transported up to the atmosphere.

Thus, these first-ever quantitative measurements of a seep blowout and the results from the numerical model demonstrate a mechanism by which methane released from hydrates can reach the atmosphere. Studies of seabed seep features suggest such events are common in the area of the Coal Oil Point seep field and very likely occur elsewhere.

The authors explain that these results show that an important piece of the global climate puzzle may be explained by understanding bubble-plume processes during blowout events. The next important step is to measure the frequency and magnitude of these events. The UCSB seep group is working toward this goal through the development of a long-term, seep observatory in active seep areas.

http://www.bubbleology.com/seeps/Seep_Blowout.html is the video. Pretty cool eh?

 

[Andre]

Thanks for that Mk, terrific find.

But forget about those conclusions:

If global warming continues, we may reach a tipping point wherein 'frozen' hydrocarbons (called hydrates), will release tremendous amounts of greenhouse gases.
Greenhouse gases are know to be a major factor in causing global warming

If hydrates start to decompose and release greenhouse gases explosively, this could accelerate the global warming trend, and in a vicious cycle, cause the release of additional greenhouse gases from more decomposing hydrates.

Those are mere speculations.
We have actually some rather good evidence that the clathrate outbursts of the Amazon fan 13-14 ky ago ( http://www.sciencedirect.com/science?_ob=ArticleURL&_aset=V-WA-A-W-V-MsSAYWA-UUW-U-AACDAEVBVU-AACVDDCAVU-VWBDVVZV-V-U&_rdoc=2&_fmt=summary&_udi=B6VBC-4FTS349-3&_coverDate=11%2F30%2F2005&_cdi=5923&_orig=search&_st=13&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=34ba507510ba43bcc8c92b58f0eb76f6) did cause the -alleged cold- Younger Dryas by upwelling of cold deep waters, drastically cooling the ocean surface waters. No match for not more than 1 ppmv increase in atmospheric CH4 that oxidates into CO2 within some decade.

 

[ravenprp]

Thank you for sharing this fascinating article about the methane clathrate explosion that was filmed and studied by divers and scientists from UC Santa Barbara. It's incredible to see such a rare and powerful event captured on video and studied in detail. The fact that this was the first time numerical data was collected on a seep blowout makes it even more significant.

It's also interesting to learn about the potential impact of these events on climate change, as almost all of the methane released during the blowout was transported to the atmosphere. The use of a numerical model to estimate methane loss in different scenarios is a valuable tool for understanding and predicting these events.

It's great to see that the UCSB research team is continuing to study and monitor seep blowouts in order to better understand their frequency and magnitude. The development of a long-term seep observatory is a crucial step in furthering our knowledge of these events and their potential impact on our environment.

Overall, this article highlights the importance of continued research and monitoring of natural phenomena like methane clathrate explosions. Thank you for sharing this interesting and informative piece.