BP’s massive oil spill will become the largest ever in the Gulf of Mexico by Thursday based on the highest of the federal government’s estimates, an ominous record that underscores the oil giant’s dire need to halt the gusher. The oil that’s spewed for two and a half months from a blown-out well a mile under the sea is expected to surpass the 140 million gallon mark, eclipsing the record-setting Ixtoc I spill off Mexico’s coast from 1979 to 1980. Even by the lower end of the government’s estimates, at least 71.2 million gallons are in the Gulf.
The oil calculation is based on the higher end of the government’s range of barrels leaked per day, minus the amount BP says it has collected from the blown-out well using two containment systems. Measuring it helps scientists figure out where the missing oil is, hidden below the water surface with some even stuck to the seafloor. Oil not at the surface damages different parts of the ecosystem.