Rate: how much oil was flowing into the Gulf each day?
Rate = total volume of oil leaked/ # of days leaking
Exercise: calculate the oil flow rate April 27 or April 29, about a week after the explosion.
Compare your results with SkyTruth’s
April 25 = 2,103 km2
SkyTruth didn’t calculate a volume or flow rate for this date. If their area calculation is different from yours, calculate for them what the volume and flow rate was on this day, based on their interpretation of the images.
Area = 5,783 km2
Volume = at 1 µm thick = 5,783 cubic meters (m3) of oil or 36,374 barrels
Rate =36,374 barrels/7 days = 5,196 barrels/day
SkyTruth concluded that, at a minimum, more than 5,000 barrels were spilling to the Gulf each day by April 27. They didn’t calculate on April 29. If you calculated the size of the spill on April 29, how much larger did it get in just 2 days?
But if 3% of the area was 100 µm thick, as the BP executive said, and the remainder (5,609.5 km2) was 1 µm thick then the volume is: 22,960 m3 of oil; 144,414 barrels.
May 1: 6,734 km2
Combining satellite imagery with aerial overflights by the Coast Guard, SkyTruth estimated a flow rate of 26,500 barrels/day.