Flaring (?) Off Nigeria’s Coast

We’ve been routinely watching the coast of Nigeria for oil spills (like the recent ExxonMobil offshore pipeline spill that’s affected 20 miles of coastline) and other incidents.  Lately we’ve noticed what appears to be something burning far offshore, approximately 75 miles southwest of Brass on the Niger Delta. We went back as far as July on MODIS satellite images to see what we could find, and we did find evidence of burning going on multiple times over the past few months at that location, as you can see in the images below.

Is this continuous flaring (the burning off of unwanted natural gas) from a deepwater oil production platform, or from a drill rig?  Does anybody know who is currently operating out there?  Any help “sea-truthing” this site would be greatly appreciated!

The location is 3.477568° North latitude, 5.569900° East longitude.

Look for red “hotspots” on MODIS 7-2-1 infrared images, and long smoke plumes on the MODIS True Color images:

Flaring visible on MODIS Terra 7-2-1 on 8/30/12
Flaring visible on MODIS Terra 7-2-1 on 11/4/12

 

MODIS Terra True Color image 11/16/2012 showing smoke plume extending 100 miles southwest of the flaring site.

 

Bilge Dumping? Busted Using Satellite Images and AIS Data

Remember that 92-mile-long bilge dump off Congo and Angola that caught our attention back in April?

SkyTruth Angola no markups
Envisat ASAR satellite radar image showing bilge-dump slick (long dark streak) off Angola on April 6, 2012. Image courtesy European Space Agency.

The bright spot at the left end of the slick is likely the vessel that caused it.  But the ASAR imagery left an important question unanswered: Who was responsible for this pollution?

With the generous help of our new partners, SpaceQuest, new information has surfaced that helps put a name on that bright spot:  the Dona Liberta, a refrigerated cargo ship owned by NaviFruit LTD. This vessel has made unfortunate news in the past.  On July 4, 2011, the ship’s captain dumped two Tanzanian stowaways in Liberia’s territorial waters, strapped to empty barrels. One of the stowaways died while receiving medical treatment after washing up on shore. In November 2011 the vessel was laid up in the River Fal in England, stranding two Romanian watchmen on board in unsanitary conditions who were rescued by a charitable organization. And in February 2012, the Dona Liberta spilled 70-90 gallons of oil in the River Fal, prompting a cleanup response from local authorities.

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The Dona Liberta, courtesy of Shipspotting.com © Juan B

So how did we figure this out?

Read all about it after the jump….

In the ASAR satellite radar image, we can determine the exact time and date of the event, the coordinates of the start and end point of the slick, the length of the slick, and the heading of the vessel:

SkyTruth Angola w Markup

 

SpaceQuest builds satellites that intercept Automatic Identification System (AIS) data broadcast by vessels at sea.  AIS data typically include a vessel’s identification, position, heading and speed. Vessels broadcast this information, and collect it from others, to help avoid collisions with other vessels.  Insurance companies require the use of AIS by most commercial, insured vessels that are underway.  SpaceQuest gave us AIS data for the region spanning a 24-hour period, enabling us to identify vessels that were operating in the area around the same time the radar image was taken. After doing some simple math, we had enough information to pinpoint the likely culprit.

dona_liberta4

 

The observed location of the vessel on the radar image is labeled. Red dots show the positions of vessels recorded by AIS data. Red dot at upper left marks the position of the Dona Liberta, 39 miles northwest of observed location of vessel.

AIS data for a vessel 39 miles northwest from the observed location of the ship gave a heading of 293.8° and a speed of 15 knots (17.3 mph), and identified it as the Dona Liberta. This AIS information was broadcast 2.25 hours after the radar image was taken. If the ship traveled for 2.25 hours at 17.3 mph, then the ship traveled 38.925 miles, very close to the measured distance between the observed location and the AIS position.

dona_liberta5

The heading of the ship was reported by AIS to be 293.8°, only 1.1° off from the measured heading of 294.9°.  I also calculated where the vessel should be, had it been traveling for 2.25 hours at the AIS-recorded heading from the location observed on the satellite imagery. The ship would have ended up only 0.79 miles from the AIS-recorded location. No other vessels appear anywhere near this location on either the radar image, or the AIS data, making the Dona Liberta a likely culprit for this bilge dumping.

dona_liberta6
Difference between AIS-recorded position of vessel and calculated position based on observed location and AIS-recorded heading and speed.

 

But a ‘good idea’ of who dumped this material really isn’t good enough. After checking back with SpaceQuest on our findings, they supplemented our data with a compilation of the Dona Liberta’s AIS data for the previous 24 hours. From that, we were able to determine more about the trajectory of this vessel:

Dona_Liberta_Track
Possible route of the Dona Liberta (green line) drawn by simply connecting the red dots (AIS recorded positions). The slick may have drifted southward under the influence of currents and surface wind.

The observed location of the vessel in the radar satellite image was bracketed by two AIS data points, so there was more information available to cross reference with our current suspect. By comparing the time of each AIS point, with the time of the ASAR image, as well as the distance between them, the rate of travel was confirmed:

dona_liberta8
The green line connects two AIS data points that bracket the observed location of the vessel. Yellow and pink lines are distances calculated from the AIS-reported speed at both points, resulting in predicted positions for the vessel that are nearly identical to the actual observed location on the radar image.

The distance between the eastern AIS position to the observed location (yellow line) is 16.9 miles, and the vessel’s speed according to AIS was 15.1knots (17.377 mph), giving a travel time of 58.4 minutes. The actual time difference between the radar image and the AIS broadcast is 54 minutes. On the other side, the distance between the western AIS point and the observed location (pink line) is 9.66 miles, with the vessel speed at 15.2 knots (17.49 mph), implying a travel time of  33.1 minutes compared with the actual time difference of 36 minutes. These measurements are not exact but are very close, with no other vessels in the vicinity that could be confused with the Dona Liberta.

 

Bilge dumping is illegal in the United States, Europe and Canada.  We don’t know what the law is governing bilge dumping off Angola. But we’re encouraged that we now have the tools to not only spot this activity, but to identify the likely offenders. And if they don’t care, maybe their insurers and clients will.

Extreme Bilge Dumping, Angola

UPDATE: We figured out who the culprit was! Read all about how we identified the guilty party- FROM SPACE:


Original Story: We’ve been collecting quite a number of images showing the ongoing problem of bilge dumping across the globe and here is one that really catches the eye. This image, courtesy of the European Space Agency, was captured off the coast of Angola on April 6. It shows what appears to be an oily bilge dump approximately 92 miles long. The bottom image shows that you can clearly see the vessel that is probably responsible, circled in red:

 Radar satellite image showing a 92 mile long bilge-dump slick, taken on April 6, 2012. Envisat ASAR image courtesy European Space Agency.

 
You can be sure that we look at images such as this everyday and when we see ’em, you’ll see ’em. Eyes everywhere.

Where’s the Fishing?

Apparently, off southern South America, it’s just outside the Exclusive Economic Zone (EEZ) of Chile.

Here’s another nighttime DMSP satellite image composite from our friends at NOAA’s National Geophysical Data Center (as always, click to see a bigger version). We’ve planted it in Google Earth. It was made by combining three years worth of cloud-free nighttime satellite images, with 2011 displayed in red, 2010 in green and 2009 in blue. Look at the patterns of color out in the ocean, massed against Chile’s EEZ boundary, shown as a green line:

These patterns are probably made by the lights of fishing vessels: cargo ships are in a hurry to get from Port A to Port B, and don’t linger in the open ocean.  There are a variety of fishing restrictions within Chilean waters designed to protect local fishing and fisheries by limiting industrial fishing, but on the high seas beyond the EEZ boundary anything goes.  The fishing within Chile’s territorial waters must be relatively good, because this map shows that fishing vessels are trying to get as close as possible without crossing the line — although if you look closely, you can see indications of repeated incursions into Chilean waters.

Based on a study of Chilean fisheries, we think much of the fishing effort revealed on this image is probably targeting swordfish.

Bilge Dumping off Vietnam – February 22, 2012

We’ve posted about bilge dumping before – the practice of flushing the oily slop out of your vessel, straight into the ocean.  It’s illegal in a lot of places, but it is very hard to enforce.  SkyTruth’s daily offshore monitoring program just caught this fine (awful?) example of bilge dumping off the coast of Vietnam, in a major north-south shipping lane about 115 miles offshore:

Envisat ASAR satellite radar image off Vietnam, February 22, 2012. Image courtesy European Space Agency.

Zooming in on those black streaks, and turning the image west-up, here’s a closer look at this mess:

Envisat ASAR image courtesy European Space Agency.

More images and analysis after the jump….


The slick at bottom left is 30 miles long. Assuming the oil is only one micron thick – that’s probably way too conservative – we calculate this slick holds at least 16,600 gallons of oily gunk:

Envisat ASAR image courtesy European Space Agency.

Busted!  Sort of.  Following the visible stern wake, we come to a vessel 30 miles away, the likely perpetrator for this particular slick:

Envisat ASAR image courtesy European Space Agency.

If anybody has access to AIS (automated identification system) data, they can probably ID this vessel for us.  It’s location is  12.820307° N / 111.724137° E, heading 33°, time 02:37:19 UTC on February 22, 2012.  Go get ’em!