Deepwater Horizon Oil Spill and Remote Sensing
The Fire
On the 20th of April, 2010, while conducting oil exploration drilling in 3,000 feet of water in the Gulf of Mexico, the drill rig DEEPWATER HORIZON suffered an explosion and fire resulting in the loss of 11 lives and the destruction of the rig. It was assumed that the blowout preventers had stopped the oil from the well head from leaking.
They were wrong.
On the 22nd of April it was found that the blowout preventers had failed and the first of the oil sheens began appearing in what would be the worst oil spill in recorded history. The spill caused:
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A leak rate of up to 2.5 million gallons per day (at height of spill)
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A total of 210,000,000 gallons spilled over 87 days
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From 2,500 to 68,000 square miles affected
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1.84 million gallons of dispersant used
The Spill
As the spill was discovered, responders from all across the world converged on the Gulf of Mexico. Initially standard spill response techniques were employed to fight the spill including:
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Oil containment and skimming
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Oil dispersants
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In-Situ Burning
Knowing the extent of any spill is important, in a spill of this magnitude, it is vital. Observers were sent out on boats and aircraft to determine the size of the spill, to aid in coordinating the response, and to determine if methods are effectively removing the oil (SMART). As observation reports began coming in the Incident Command Post realized the overwelming size of the spill. Additional resources were needed to gain a higher view of this incident.
Tracking the spill, use of Remote Sensing
With the spill covering thousands of square miles and with the introduction on unprecedented amounts of oil dispersants, monitoring of the spill was beyond standard methods. Boat and aircraft observations gave a limited overview so a view from space was needed. By utilizing an entire constellation of satellites the oil was tracked using high resolution Synthetic Aperture Radar (SAR), multispectral imaging (UV, visible, NIR), and infrared imaging.
The MODIS instrument is operating on both the Terra and Aqua gave large spatial resolution across this area giving multispectral imaging of the Gulf of Mexico. With the addition of Airborn Visible Infrared Imiging Spectrometer (AVIRIS) carried on NASA's ER-2 aircraft, data the oil thickness could be determined allowing higher degree of estimates of the amount of oil present on the surface of the water.
The use of Synthetic Apeture Radar (SAR) was the most effective allowing the tracking of oil slicks since slicks damp strongly short waves measured by SAR and oil spills appear as a dark patch on the SAR image due to the difference in reflectance between clear water and oil covered water.
The result was a wide field view of the movement of the oil over time and data on the amounts present allowing first responders to be able to anticipate the oil movement. This allowed pre-staging of the oil response vessels and shore side assets to more effectively combat this spill of national significance.
Satellite data became an integral part of the Unified Command that was established to combat the spill. The Situation Unit regularly updated the imagery for the NOAA Scientific Support Coordinator to analyze and evaluate to make recommendations as to not only where the spill response equipment should be deploying, but how much would be needed to be effective.
Deepwater Horizon oil spill - May 24, 2010 - with locator" by NASA/GSFC, MODIS Rapid Response AND demis.nl AND FT2
AVIRIS map over the Louisiana coast
LSU Earth Scan Lab, May 11, 2010 23:57 SST/SAR of the DWH
Timelapse uses imagery from the MODIS instrument, on board NASA's Terra and Aqua satellites
The extensive use of satellites in the Deepwater Horizon oil spill response highlighted the benefits of satellite imagery in tracking oil spills, big and small, giving data that previously would have taken hundreds of man hours and multiple platforms at the surface. This allows for a more effecting response to spills worldwide.
Today, NASA and NOAA satellites are providing the U. S. Coast Guard with offshore data on potential oil spills at sea that would have otherwise gone undiscovered. This eye in the sky gives responders an important tool in protecting our oceans from environmental damage.