BP / Gulf Oil Spill – June 12 MODIS/Aqua Image

This MODIS/Aqua satellite image, taken on June 12, has a broad sunglint pattern centered on the eastern Gulf that effectively illuminates the main oil slick as well as areas of what we interpret as much thinner sheen. The bright band of sunglint spanning this image reveals fine structure (squiggly bright lines) in areas to the east of what we interpret as the main area of oil slick; this structure can be caused by natural surfactants, or it may indicate very thin layers of residual sheen related to the ongoing spill. As on June 9, there is some ambiguity in our delineation of the area of slicks and sheen (orange line), which extends across an area of 23,140 square miles (59,932 km2) — as big as our home state of West Virginia:

MODIS/Aqua satellite image taken June 12, 2010

Oil appears to be making landfall across 40 miles of coast east of Mobile Bay, from Gulf Shores, Alabama to Perdido Key, Florida. Tendrils of oil, possibly thin sheen, reach toward the Florida coast from Pensacola almost as far east as Panama City. Some news accounts support this analysis.

And the government just revised the estimated leak rate from the well – they now say it’s leaking anywhere between 1.5-2.5 million gallons per day, with the containment device currently capturing about 500-600 thousand gallons of that flow. That means that since BP cut the riser and installed the latest containment cap, at least 900 thousand gallons – and possibly as much as 2 million gallons – have entered the Gulf daily. At the high end that’s nearly twice as much as the 1.1 million gallon estimate SkyTruth and Dr. Ian MacDonald of Florida State University made back on May 1.

BP / Gulf Oil Spill – Memo Shows BP’s Spill Rate Calculations

Dr. Ian MacDonald at Florida State University just provided us with this BP memo detailing the spill-rate calculations performed by BP. Click it to see the full-sized version. We guess this is how BP came up with their very low estimated leak rates of 42,000 gallons (1,000 barrels) and 210,000 gallons (5,000 barrels) per day. The official estimated leak rate now stands at 20,000-30,000 barrels per day (and possibly much higher).

Read more about the varying spill-rate estimates, and this memo, in a Washington Post article by Joel Achenbach.

BP / Gulf Oil Spill – June 7 and June 9, 2010

Playing some catch-up from Capital Hill Ocean Week. We served on a panel yesterday and gave a presentation on the spill (starting at 36:10 in this video). Thanks for your patience, we’re stretched pretty thin!

Here are MODIS/Terra satellite images of the Gulf from June 7 and June 9. The image taken June 7 shows slick and sheen across an area of 9,075 square miles (23,504 km 2). A large dark area west of the slick may be a low-wind area within the generally bright belt of sunglint west of the Mississippi Delta. There may be slicks or sheen obscured by this low-wind region:

MODIS/Terra satellite image taken June 7, 2010

Compare this with the MODIS/Terra taken on June 9, which has a broad sunglint pattern centered on the eastern Gulf that effectively illuminates the main oil slick as well as areas of what we interpret as much thinner sheen. The bright band of sunglint spanning this image reveals fine structure (squiggly bright lines) in areas to the north, south and west of what we interpret as the main area of oil slick; this structure can be caused by natural surfactants, or it may indicate very thin layers of residual sheen related to the ongoing spill. Lots of judgment calls made when encircling the area of slicks and sheen (orange line), but we come up with a total area of 16,434 square miles (42,565 km2):

MODIS/Terra satellite image taken June 9, 2010

We don’t think the actual area of ocean affected by slicks and sheen nearly doubled in just two days; instead, we think the MODIS image from June 9 was just much more effective at showing those areas than many of the images we’ve been collecting throughout this incident. And it is possible that some of the area we’ve delineated contains natural surfactant rather than spilled oil. Again, a difficult image to interpret in some areas.

Platform 23051 vs. Ocean Saratoga Rig – Not The Same Thing?

UPDATE 6/11/10 4pm – We’re wondering if Platform 23051 was destroyed by Hurricane Ivan in 2004, and if the Ocean Saratoga rig is actually working at the site of the destroyed platform. This would make a lot of sense. If anyone has information that would confirm (or refute) this, please let us know.

UPDATE 6/11/10 5pm – John Wathen tells me that the pilot collected a GPS location while they flew over the Ocean Saratoga rig last weekend. John gave me the GPS coordinate, and it plots right on top of the MMS-given location coordinate for Platform 23051. So I think the platform was destroyed by Ivan, and the leaking well that the Saratoga is working to plug is the well that was under Platform 23051.

Conclusion: the persistent slicks we’ve been seeing on multiple satellite images are apparently caused by the continuing leakage from this hurricane-damaged well. It would be great if someone from MMS or the Coast Guard would confirm this.

Some recent media reports about our work related to possible leaks unrelated to the BP spill have gotten a few things wrong. Here’s a clarification: based on our analysis of multiple satellite images collected since April 25, we see what appears to be a small but persistent oil slick at or very near the known location of Platform 23051. According to MMS this is a fixed oil platform, installed in the 1980s, that has a crew onboard. If this is indeed a small oil slick, it might indicate a small chronic leak related to that facility; it might also be coming from a natural oil seep on the seafloor at or near the platform. There may be other causes that we are not aware of.

Based on the location we published for that platform (a location obtained from the MMS platforms database), a professional photographer flew over the general vicinity and documented what appeared to be an oil slick next to a semisubmersible drill rig. A company news release explains that this rig, the Ocean Saratoga, is working to plug a well that was damaged by Hurricane Ivan back in 2004. The well was reportedly covered by a seafloor landslide, so this is a difficult operation.

None of this changes our main question: how common are smaller spills like this, whatever their cause? What are the impacts? Is this a problem in the Gulf, or not? Would it be a problem with drilling elsewhere, such as in the Arctic or off the coast of Florida?

Routine Gulf Monitoring – Here’s Why We Need It

UPDATE 6/8/10 9am – check out video from an aerial overflight of the apparent oil leak next to the Ocean Saratoga semisubmersible drill rig, working ten miles offshore in Mississippi Canyon Block 20. We’re still trying to determine if this is the potential leak that we identified on satellite imagery as possibly coming from Platform 23051, or if this is yet another apparent oil leak in the same vicinity.

NOAA actually mentions the oil leak near the Saratoga in this map published back on April 30. The Mobile Register wrote about this yesterday.

UPDATE 6/8/10 3:30pm – This blogger uses some interesting language, but reports that the Ocean Saratoga is working to plug a well that had been damaged by Hurricane Ivan in 2004. No explanation why there would be oil in the water as a result of this plugging operation. This also doesn’t explain the possible leak we see on multiple satellite images of Platform 23051.

UPDATE 6/9/10 7:15pm – Some media reports are misrepresenting SkyTruth’s work: we never claimed the Ocean Saratoga was leaking oil; our satellite image analysis indicates a possible persistent leak at or near Platform 23051, which is in the same general vicinity in the Gulf. These are two separate structures – one is a mobile drilling unit (MODU), the other is a fixed platform.

Three days ago we blogged about a possible small, but persistent, leak from offshore oil platform #23051 in the Gulf of Mexico, not far from the ongoing Deepwater Horizon spill. We asked for confirmation from anyone who might happen to be in the vicinity. Ask, and ye shall receive:

Photograph taken 6/5/10 of apparent oil leak in the vicinity of Platform 23051, courtesy J Henry Fair. Semisubmersible drill rig in foreground; workboat at left where the plume originates at the surface. Note a second plume apparently originating from platform in the background at upper right; this may be Platform 23051 (not yet confirmed).

Professional photographer J Henry Fair flew over the site yesterday using the MMS platform location in our blog post, and took photos of what he found. Here are the two he sent us today. There is an obvious plume of oil in the water next to a semisubmersible drill rig. J Henry identified it as the Ocean Saratoga rig (nice picture here), owned by Diamond Offshore.

The May 17 rig status report available on Diamond Offshore’s website (which prominently features a photograph of Senator Mary Landrieu, with the caption “Credit where credit is due”) shows the Ocean Saratoga is currently under contract to drill for the same company that owns and operates Platform 23051. The platform may be the one visible in the background of the photo above, apparently trailing another oily-looking plume. So it’s possible that we’ve actually discovered two separate leaks or spills in the same vicinity.

A closer look at the semisubmersible rig, work boat, and apparent plume of oil near the location of Platform 23051 in the Gulf of Mexico, taken June 5, 2010. Photo courtesy J Henry Fair.

J Henry described the workboat at the end of the oil plume as “churning the oil” as if to disperse it more quickly. It’s unclear from these pictures if the workboat is itself the source of this oil plume, or if indeed it’s motoring around where an oil plume is emerging at the ocean surface in an attempt to break it up. In any event, this spill is certainly large enough to require reporting to the Coast Guard.

Other than us – is anybody watching what’s going on out there?

This is why we think America needs publicly transparent, routine satellite monitoring wherever we allow offshore oil and gas drilling.