Subscribe to Making Waves

Ocean Service Feeds

What is a Podcast?

A podcast is a an audio file published on the web. The files are usually downloaded onto computers or portable listening devices such as iPods or other players.

Read more about podcasting from

Find other podcasts from the US government

Making Waves: Episode 90 (January 26, 2012)

You're listening to Making Waves from NOAA's National Ocean Service. I'm Troy Kitch.

The Deepwater Horizon oil spill in the Gulf of Mexico may be long over, but much work continues to clean up the region and to better understand the harms caused by the estimated five million barrels of oil that discharged into the Gulf. Today, we’re going to look at a new NOAA-led study that independently looked at how fast gases and oil were leaking into the Gulf before the wellhead was capped in July 2010 … and we’re going to tell you about a draft plan now out for public comment that lists initial projects to receive funding from the billion dollar Early Restoration Agreement announced by the spill Natural Resource Trustees and BP back in April 2011.

(New Study)
First, let’s take a look at the new study. NOAA scientists and academic colleagues have independently estimated how fast gases and oil were leaking during the Deepwater Horizon oil spill by combining chemical measurements in the deep ocean, in the oil slick, and in the air.
This information about the transport and fate of different components of the spilled gas and oil mixture could help resource managers and others experts who are trying to better understand environmental exposure levels.
The new chemistry-based spill rate estimate came out to an average of 11,130 tons of gas and oil compounds per day. That’s very close to the official average leak rate estimate of about 11,350 tons of gas and oil per day (that’s about 59,200 barrels of liquid oil every day during the spill). That official estimate was based on things like video flow analysis, pipe diameter, and fluid flow calculations.

Authors of the new study found that the leaking gas and oil quickly separated into three major pools: the underwater plume about 3,300-4,300 feet below the surface, the visible surface slick, and an airborne plume of evaporating chemicals. Each pool had a very different chemical composition.
The team found that the underwater plume was enhanced in gases known to dissolve readily in water. This included essentially all of the lightweight methane (better known as natural gas) and benzene (a known carcinogen) present in the spilling reservoir fluid. The surface oil slick was dominated by the heaviest and stickiest components, which neither dissolved in seawater nor evaporated into the air. And the airborne plume of chemicals contained a wide mixture of intermediate-weight components of the spilled gas and oil.  
The visible surface slick represented about 15 percent of the total leaked gas and oil; the airborne plume accounted for about another 7 percent. About 36 percent remained in a deep underwater plume, and 17 percent was recovered directly to the surface through a marine riser. The remaining 25 percent of the total leaked gas and oil was not directly accounted for by the chemical data the team analyzed. 

The new study, Chemical data quantify Deepwater Horizon hydrocarbon flow rate and environmental distribution, was published online in the journal Proceedings of the National Academy of Sciences USA.
We’ll have links to that study in our show notes at

(Early Restoration Plan)

If you would like to contribute to official plans to restore natural resources damaged by the Deepwater Horizon oil spill, here’s your chance. The Deepwater Horizon Natural Resource Damage Assessment Trustees are now seeking public input on the Deepwater Horizon Draft Phase I Early Restoration Plan & Environmental Assessment released last month.

The plan represents a first step toward restoring resources injured by the spill. It proposes a series of initial projects to receive funding from the billion-dollar Early Restoration Agreement announced by the Natural Resource Trustees and BP back in April 2011.  Early restoration actions are meant to begin the restoration process before the natural resource damage assessment process is complete and the full extent of the harm to the Gulf ecosystem is known. 

The eight proposed projects include two each in Alabama, Florida, Louisiana, and Mississippi.  These e arly r estoration projects include actions that help lay the groundwork for rebuilding coastal marshes, restoring wetlands and barrier islands, conserving sensitive habitats for wildlife and improving people’s use of natural resources in the Gulf of Mexico.

Your input is very important to this process. You can weigh in on the plan at one of the public meetings to be held in Gulf Coast communities and Washington, DC, this month and in February. And you can also comment online through February 14. We’ll have a link to the meeting schedule and to the place to go to comment online. As always, check our show notes.

And that’s it for this week.  

If you have any questions about this week’s podcast, about the National Ocean Service, or about our ocean, send us an email at  You can find us on the web at … and we’re on Facebook and Twitter. Our handle is usoceangov.

You’ve been listening to Making Waves from NOAA’s National Ocean Service.  We will return in two weeks.