BP / Gulf Oil Spill – Moving Toward Florida Straits (??)

We just finished analyzing the MODIS / Aqua satellite image shot the afternoon of May 27. It again clearly shows the main body of the oil slick (solid orange line) around the site of the leaking Macondo well, and also shows deep entrainment in the Loop Current. Disturbingly, we see signs of thin surfactant – possibly oil from this spill – in the Loop Current where it moves past the Dry Tortugas and toward the Florida Straits (dashed orange line):

MODIS / Aqua satellite image, May 27, 2010

There are natural processes that generate thin layers of oily surfactant, so this does not necessarily show that oil from the spill is moving into the Straits yet. But the spill has clearly been interacting with the Loop current since May 17, and at a speed of 1 to 2 knots (see below), ten days is enough time for some of that oil to have moved 240 to 480 nautical miles (276-552 miles). Although it’s 510 miles as the crow flies from the leaking well site to Florida Straits, the convoluted path taken by the Loop Current adds up to a total distance of about 900 miles, so we may not be there yet. Consider this a possibility, not a definitive conclusion.

Systematic water sampling in the eastern Gulf sure would be helpful to pin this down – is anyone doing that?

Sea-Surface Velocity (SSV) map derived from satellite radar altimeter data, May 27, 2010. Location of the Loop Current is indicated by green to red band of relatively high velocity at the ocean surface. Source: Colorado Center for Astrodynamics Research.

BP is currently trying out the “top kill” procedure to plug the leaking well. The success of this attempt is still uncertain, but at least the blowout preventer appears to be hanging together under the increased strain. Live video feed shows what appears to be a strong plume of oil and drilling mud coming from one of the leaks in the busted-up riser pipe. Keep your fingers crossed – this really needs to work.

BP / Gulf Oil Spill – 39 Million Gallons And Growing

The MODIS / Terra satellite image of the Gulf taken yesterday (May 24, 2010) is a relatively cloud-free look at the ongoing oil spill in the eastern Gulf of Mexico. Areas covered by oil slick and sheen are marked with a solid orange line. Areas where we think there may be slicks and sheen, but our analysis is of lower confidence, are shown by dashed orange lines. All together, slicks and sheen are possibly covering as much as 28,958 square miles (75,000 km2). That’s an area as big as the state of South Carolina:

MODIS / Terra image, May 24, 2010, with SkyTruth analysis

We also though it would be interesting to produce a matching version of this image with none of our annoying annotation:

MODIS / Terra image, May 24, 2010, with no analysis or annotation

It’s Day 35 of this fatal incident. Our estimated spill rate of 1.1 million gallons (26,500 barrels) per day, now on the conservative end of the scientific estimates, leads us to conclude that almost 39 million gallons of oil have spilled into the Gulf so far. BP and the federal government had said that they would announce a new official estimate of the daily spill rate on May 22, but we’ve heard nothing more about that. As far as we can tell, they are still claiming the spill rate is 210,000 gallons (5,000 barrels) per day. At that much lower rate, the total amount spilled would be 7.35 million gallons.

BP / Gulf Oil Spill – Satellite Images Show Spreading Slick

The MODIS / Terra image taken on Saturday, May 22 shows oil slick and sheen covering 16,538 square miles (42,833 km2):

MODIS / Terra satellite image, May 22, 2010.

Clouds and haze obscure the southeastern Gulf, but a small patch of what might be oil entrained in the Loop Current is visible. As we’ve said before, it is possible the Loop Current has a distinct color even without the presence of oil, so this is a low-confidence analysis and therefore is shown with a dashed orange line. Sure wish they’d send a vessel out there to do some sampling transects. Note the very broad area of sunglint covering the western half of this image. Look closely and you’ll see a cluster of thin, bright, arcuate patches southwest of the Mississippi Delta; these are very thin oil slicks caused by persistent natural oil and gas seeps on the seafloor. I’ve seen a few of these seeps up close and personal from a research submarine, the Johnson Sea-Link II.

This radar image from Canada’s RADARSAT-1 satellite (a real workhorse, still cranking after many years in orbit), also taken on May 22, shows detail of the main body of oil slick around the leaking well site and the Delta. Compare with the MODIS image above:

RADARSAT-1 image, May 22, 2010. Image courtesy CSTARS.

And this MODIS / Aqua image taken the next day, May 23, shows slick and sheen spread widely throughout the eastern Gulf, possibly covering as much as 18,670 square miles (48,356 km2) if we include both the high- and low-confidence areas:

MODIS / Aqua satellite image, May 23, 2010.

BP / Gulf Oil Spill – Deeper Into Loop Current (??)

The MODIS / Terra image taken today shows a very faint, long belt of anomalous ocean color that appears to follow the Loop Current. We have very tentatively identified this as possible oil slick and sheen carried far to the south. Consider this a low-confidence analysis; it’s possible that the Loop Current has a distinct ocean-color signature without any oil present:

MODIS / Terra satellite image, May 21, 2010.

BP / Gulf Oil Spill – Radar Image, May 18, 2010

This Envisat ASAR radar satellite image taken on May 18 shows oil slick entrained in the Loop Current and spreading out to the southeast. Slick and sheen covers 15,976 square miles (41,377 km2), about 50% larger than seen in yesterday’s MODIS image and about twice the size of New Jersey:

Envisat ASAR image, May 18, 2010. Image courtesy CSTARS.

Some of that apparent rapid growth may be due to the fact that radar images are generally a lot better at showing areas of thin sheen than the MODIS imagery.

See all of our images related to this incident here.
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BP / Gulf Oil Spill – How Big Is It?

It’s time to revisit this subject. NOAA and BP are still saying the spill rate is 210,000 gallons (5,000 barrels) per day, despite plenty of evidence to the contrary. Many in the media continue to uncritically accept this estimate.

Why is it important to get this number right? This is about more than just liability, or PR. You can bet that our future response capacity is going to be overhauled and retooled based on this spill. If we low-ball the spill amount and rate, we run the risk of designing an inadequate new spill-response system that is doomed to fail the next time something this big occurs.

A couple of thoughts:

1) Are we really being asked to believe that the spill-response capability of one of the world’s biggest oil companies AND the United States Coast Guard has been totally overwhelmed by a spill of just 210,000 gallons per day? That’s a big spill, but not nearly as big as could reasonably be anticipated. Plenty of wells in the Gulf produce more than that under controlled flow-rate conditions; plenty of tankers plying our waters hold millions of gallons of oil.

2) BP claims the siphon they’ve inserted into the end of the damaged riser pipe is diverting 84, 000 gallons (2,000 barrels) of oil per day from the main leak to a tanker at the surface. That is good news indeed. But it’s worth remembering that for nearly a week BP stated the total spill rate was only 1,000 barrels per day.

3) Scientists analyzing video of that main leak, apparently shot on May 11 and released by BP on May 12, have estimated the flow rate from that leak to be anywhere from 20,000 to 100,000 barrels per day. This makes SkyTruth’s 1.1 million gallon (26,500 barrel) per day estimate, based on our measurements of the oil slick as observed on satellite images and mapped by the Coast Guard, look fairly conservative. And it doesn’t even include the additional 15-20% coming from the secondary leak. That means BP’s siphoning effort is only capturing, at best, about 10% of the flow. This video of the main leak, shot on May 17 after the siphon was inserted and apparently working, shows the plume of oil continuing to spew into the Gulf; it hardly looks abated.

4) Speaking of which: video shot on May 15 and 16 has just been released showing the secondary leak, where the riser pipe is kinked and bent about 90 degrees a few feet above the blowout preventer stack. Unlike the short, blurry clip of the main leak, this video is several minutes long and quite sharp.

BP / Gulf Oil Spill – Slick Now Entrained In Loop Current?

Today’s MODIS / Terra satellite image is the most cloud-free we’ve seen in many days, and what it reveals is disturbing: part of the still-massive Gulf oil slick has apparently been entrained in the strong Loop Current, and is rapidly being transported to the southeast toward Florida. The total area covered by slick and sheen, at 10,170 square miles (26,341 km2), is nearly double what it appeared to be on the May 14 radar satellite image, and is bigger than the state of Maryland:

MODIS/Terra image, May 17, 2010, showing slick apparently entrained in Loop Current.

From Weather.com today:

Per The Weather Channel’s tropical expert Dr. Richard Knabb, “based on satellite images, model simulations, and on-site research vessel reports, I think it is reasonable to conclude that the oil slick at the surface is very near or partially in the loop current. The loop current is responsible in the first place for extending that stream of oil off to the southeast in satellite imagery.”