Investigating the oil plume with a blog

201005280848.jpg from the Walton Smith

Well it looks like that grant from the NSF I mentioned a few days ago is being put to use.

Remember plumes of underwater oil found a few weeks ago? They are back in science news. The same researchers are on a new ship and back out for two weeks. They are taking samples and letting us know about their work via a blog. It is fascinating reading.

They are working 24/7 on gathering and analyzing data, including looking at methane levels. This work is funded by the National Science Foundation and has some researchers from UCSB on it. Since that is who got the grant from NSF, I think it is likely that some of that money is going to help fund this trip, perhaps their methane analysis. David Valentine has an opinion piece in Nature about the work that needs to be done over the next few months by the research community. He says this about dissolved methane:

A promising technique is to measure the plumes of dissolved methane emanating from the site. Methane gas is the most abundant compound in the spill, constituting approximately 40% of the leaking petroleum by mass, according to energy company BP, which controls the reservoir. Although methane from surface-vessel spills or shallow-water blowouts escapes into the air, I expect that the vast majority of methane making the long trip to the sea surface from a deep water spill would dissolve. Unlike oil, methane dissolves uniformly in seawater. And the tools are available to measure it accurately and sensitively.

And get used to hearing about CDOM – colored dissolved organic mater. Because this ship is finding a lot of it.

It turns out that the plume has moved from where it was last time. And its general character has changed:

The plume was located between 800m and 1300m in the water column and there appeared to be three distinct layers. The sensor signal for colored dissolved organic showed a robust increase in signal between 800 and 900m; then increased by about five times between 1000 and 1200m; and, between 1200 and 1300m, the signal doubled again. In these same depth ranges, the signal from the transmissometer also increased, suggesting a different suite of particles in the water between these different depths.

They are also examining methane and oxygen levels in the water. It seems that the more methane present, the lower the oxygen levels.

On Thursday they found a new plume, with very interesting features. There was less CDOM, more methane and less oxygen. It appears very likely that the degradation of the oil and methane is reducing the amount of oxygen in the water. So that this may be an older plume. The oxygen levels are not low enough to be hazardous to life, yet.

It is really cool to see the up-to-date recordings of working scientists as they find out all sorts of new and exciting bits of information about the world around us. Perhaps some researchers are seeing the benefits of putting preliminary data and insights out a little early. I’m looking forward to seeing what more they find.