BP / Gulf Oil Spill – July 4th Weekend

With oil continuing to billow into the Gulf of Mexico from BP’s failed Macondo well, the holiday weekend brought little cause for celebration, and no break for the folks working hard to clean up the oil coming ashore and to plug the leaking well. Oil was reported for the first time in Lake Pontchartrain, and the discovery of tar balls on some Texas beaches means this spill is now directly impacting all of the Gulf states.

A RADARSAT-2 satellite image taken July 2 shows oil slick and sheen still spread across a large area of the Gulf in the wake of Hurricane Alex, which brought large waves and strong gusty winds to the area last week:

RADARSAT-2 satellite image taken July 2, 2010. Image courtesy of CSTARS.

MODIS satellite images acquired on July 3 and July 4, while impaired once again by clouds, showed portions of the oil slick in a few areas. The July 3 image shows patches of slick along the Louisiana coast reaching west beyond Vermilion Bay:

MODIS/Aqua satellite image acquired on July 3


It also shows a neat little circular pattern formed by a cluster of natural oil and gas seeps; the small slicks that form at the ocean surface above these deepwater seeps appear to be caught up in a clockwise gyre (a rotating surface current).See all the images in our Deepwater Horizon Oil Spill gallery.

BP / Gulf Spill – NOAA Forecasts Long-Term Threat To Coasts

NOAA has just released the results of modeling to analyze the long term threat posed by the ongoing oil spill to coastlines throughout the Gulf, Florida Keys, and East coast shorelines:

NOAA forecast showing likelihood of coastline being threatened by oil over the long term by BP spill

Their model shows the probability that oil will approach within 20 miles of the shoreline. It assumes the net daily spill rate is 1.4 million gallons (33,000 barrels) per day for 90 days beginning April 22, when the Deepwater Horizon rig sank and the fire was extinguished. We’re at Day 76 right now, so this assumes a relief well plugs the leak within the next 2 weeks. They are steadily closing in on the target depth of about 13,000′ below the seafloor, so we’re hopeful BP will succeed ahead of their stated mid-August goal.

The model is based on historical wind and ocean current information, and accounts for the natural breakdown of oil at sea. It doesn’t account for the movement and ultimate fate of oil beneath the water’s surface, because we just don’t know enough about that yet. Read all about the model and the assumptions and data used to run it. You can also see other maps, graphics, animations and movies showing the model results for individual scenarios.

Platform 23051 / Ocean Saratoga Site Revisited

June 5, 2010: Oil slick next to Ocean Saratoga semisubmersible drill rig. Rig is working to plug leaking wells that were damaged by Hurricane Ivan in 2004. Photo courtesy J. Henry Fair.

 

June 25, 2010: Oil sheen marked by orange buoy. Rig was not observed in the area. Photo courtesy J. Henry Fair.

A few weeks ago we noticed a small but persistent slick on satellite images, appearing near a known oil platform location, designated Platform 23051 in a government database of all Gulf oil and gas platforms (including platforms that have been destroyed or removed). J. Henry Fair, a professional photographer, was flying over the site a few days later and captured photos and video showing an oil slick next to a semisubmersible drilling rig called the Ocean Saratoga. We learned the rig was not the source of any leak – it was working to plug one of 26 leaking oil wells that had been damaged by Hurricane Ivan in 2004, and have apparently been leaking ever since. Platform 23051 must have been destroyed during Ivan, or so badly damaged that it was subsequently removed.

The Coast Guard reported the wells were leaking, on average, just 14 gallons per day; and a containment device was said to be capturing most of that oil. But based on the size of the oil slick, we calculated a leakage rate in the range of 100-400 gallons per day. In our most recent observation on satellite imagery, June 18, the oil slick is 12 miles long and covers 4.5 square miles. The Ocean Saratoga is apparent as a bright dot on the radar image near the western end of the slick.

Mr. Fair flew over the site again on June 25 and took photographs showing a thin oil slick (rainbow sheen) marked by an orange buoy at one end, with no sign of the Ocean Saratoga rig or any other activity. It’s possible the rig was towed back to shore to ride out tropical storm Alex, or has been moved to another job. As long as we keep getting satellite imagery covering the nearby BP oil spill, we should have more opportunities to check up on the progress at stopping this small but persistent leak.

BP / Gulf Oil Spill – Radar Images Show Western Reach of Slick, June 28

Two CSK radar satellite images (black-and-white) are superimposed on a cloudy MODIS satellite image (color) taken June 28, 2010. The radar on the left was acquired at 6:56 pm, and the image to the right at 7:44 pm local time on June 28. Only the western half of the oil slick is visible on these images:

COSMO-SkyMed (CSK) radar satellite images acquired June 28, 2010. Images courtesy of CSTARS.

Tropical Storm Alex was roiling the Gulf when these images were taken. Weather data buoys in the vicinity recorded wind speeds of 6-11 meters/second (13-25 miles/hr), strong enough to break up areas of thin oil sheen and possibly render them undetectable. We infer that the dark areas enclosed within the orange line are thicker patches of oil slick. Oil is reaching farther to the west than we’ve seen recently, impacting Timbalier Bay and Terrebonne Bay.

SkyTruth on CNBC Tonight – “America’s Crude Reality”

Catch John Amos of SkyTruth (yes that’s me) talking about the Gulf spill, offshore drilling, and satellite images on CNBC at 8pm Eastern tonight. The show is called “America’s Crude Reality” and features SkyTruth’s testimony to Congress last fall warning of the risks posed by offshore drilling; our work on the blowout and 10-week-long spill off Australia last year; and our ongoing investigation and monitoring of the BP / Deepwater Horizon blowout and spill. Dr. Ian MacDonald, the Florida State University oceanographer who helped us calculate that the spill was at least 20 times larger than official estimates at the time, also appears tonight. Check here for show times – don’t miss it!