BP/Deepwater Horizon accident has spilled between 18 and 40 million gallons of oil into the Gulf. The large discrepancy is due to uncertainty in measuring the amount of oil gushing from the damaged BOP, uncertainty in measuring the slick/sheen on the surface and uncertainty in measuring the underwater plumes.
By comparison, the Mexican-owned (Pemex Corp.) Ixtoc I platform that caught fire and sank off the Gulf Coast of Mexico (after a similar type of blowout in 1979) spilled over 126 million gallons. It took 10 months to cap the Ixtoc I well. The famed "Hellfighter" Red Adair helped cap the Ixtoc I.
But if you look at the photo above and compare it to photos taken at the Deepwater Horizon accident site - photos of the actual firefight and those taken immediately after the sinking and subsequent to it - you can tell that the resources BP has brought to the scene far outnumber the resources the Mexican Government had on hand to battle the Ixtoc I accident.
A lot of government resources were mobilized in the aftermath of the Ixtoc I disaster to help save wildlife and wetlands. They even airlifted threatened species from areas polluted by oil.
It will be awhile before scientists and analysts know for sure how much the Deepwater Horizon spilled . . . and continues to spill. It has the potential to be worse than the Ixtoc I spill.