The estimates are at best approximate on both sides on the equation, but six weeks after the Deepwater Horizon oil rig explosion in the Gulf of Mexico, the cumulative oil spill has now reached a bit more than 3 times that of the 1989 Exxon Valdez. It is still dwarfed, however, by the estimated equivalent of 30 Exxon Valdez spills discharged into Ecuador's Amazon by Chevron/Texaco over 3 decades, or more than 50 Exxon Valdez spills into the Niger Delta by Shell, Chevron, and other companies over 5 decades.