Deepwater Horizon Oil Spill

Step 3: Explore the impact of your spill estimates

The impact of imagery

In the first few days after the explosion, the Coast Guard and BP told the public that only 1,000 barrels of oil per day were leaking out of the blown out wellhead. As SkyTruth began publishing its higher estimates of the spill on its blog and social media, reporters began to notice. On April 27 SkyTruth and Dr. Ian MacDonald of Florida State University estimated a flow rate of at least 5000 barrels based on the minimum thickness of oil at the surface needed to be detected by satellite imagery. They estimated a more likely flow rate of at least 20,000 barrels per day if the oil was thicker than that.  One day later, the National Oceanic and Atmospheric Administration (NOAA), responsible for fisheries and other marine life in federal waters, announced their estimate of 5,000 barrels per day. That estimate remained the official government estimate for weeks.

newspaperThe Guardian Article “Gulf oil spill ‘five times’ larger than estimated“,  April 29, 2010

But on May 1, SkyTruth and Dr. MacDonald released a new estimate showing an even higher flow rate based on maps created by the Coast Guard after flying airplanes over the spill area. That new flow rate was over 26,500 barrels per day. Yet federal agencies and BP continued to insist that the spill rate was only 5,000 barrels per day.

Once SkyTruth revealed its estimates of the spill, news organizations reported it.

newspaperLos Angeles Times article “Oil spill five times as large as earlier thought“, April 29, 2010

Newspapers across the country revealed the discrepancy between what BP and the Coast Guard were claiming and the images analyzed by sky truth. Television and online news programs such as NBC, CNBC and others featured SkyTruth in their newscasts.

Soon thereafter, on May 19, the federal government convened a panel of scientists, called the Flow Rate Technical Group, to calculate an official flow rate. A week later, the group of scientists estimated a minimum flow rate of 12,000 to 19,000 barrels per day.

newspaper New York Times article “Estimates Suggest Spill Is Biggest in U.S. History“, May 28, 2010

As they continued to gather new information – including video footage of the seafloor well, pressure readings from the wellhead, and computer simulations — the scientists revised their estimate upward.

newspaperWashington Post article “Scientists offer varied estimates, all high, on size of BP oil leak“, June 11, 2010

Months later, they indicated that the flow rate was 53,000 barrels per day – 53 times higher than the original Coast Guard and BP estimate.

If you want to learn more about the combination of scientific approaches the federal Flow Rate Technical Committee used to calculate a more accurate flow rate, review their final results.