Two days after Deepwater Horizon exploded, it sank. During its collapsing descent into the Gulf, it broke a pipe leading to the oil reservoir. For months thereafter, the uncapped well at Mississippi Canyon 252 (MC252) gushed oil into the Gulf of Mexico.
BP attempted to activate the failed blowout preventer (located underwater, after the rig collapsed), but those efforts did not work. By early June, the government estimated 21-46 million gallons of crude oil had been sent into the water since the April 20th explosion. That means every day the well was uncapped, it spewed between 504,000 and 1,050,000 additional gallons of free-flowing crude.
Using the lower end of the spectrum, that's equivalent to having a new Exxon Valdez disaster - which leaked approximately 11 million gallons of crude oil into Prince William Sound - every five days.
NOAA (the National Oceanic and Atmospheric Administration) and NASA (with its satellites) tracked the contamination plume as it moved away from Mississippi Canyon 252. Let’s examine the maps and pictures which depict the story of spreading pollution. Note that all maps are PDF links:
• Early days - oil on the Gulf is mostly located near the uncapped well.
• First week - map shows location of the uncapped well (MC252) and spreading plume between April 22-26. NOAA also predicts how far the plume will travel on April 27.
• By May 1st, the contamination reaches Chandeleur Sound and gets closer to the Louisiana coast.
• NOAA releases a “Nearshore Surface Oil Forecast” for May 31-June 1.
• On the 3rd of June, NOAA’s map depicts the location of an oil sheen and possible tarballs moving toward the Florida coast.
Satellite imagery, from NASA, correlates with NOAA’s plume maps and predictions:
• Smoke from the burning rig is visible from space on April 21st, the day after the explosion.
• A satellite view, four days later, shows the oil moving toward the Delta National Wildlife Refuge and the Chandeleur Islands. A close-up of the image shows the size of the oil slick compared to nearby ships.
• By the 27th of April, the oil plume is approaching Louisiana’s barrier islands and beaches.
• Eight days after the disaster at Deepwater Horizon, another catastrophe is in-the-making as the expanding slick threatens fragile habitats.
• As the slick grows larger, officials review evidence (on the 29th of April) that the well is discharging more oil than they originally believed.
• Nearly a month after the explosion, the still-open wellhead has discharged so much oil that the slick is just off the Mississippi Delta.
• By the 24th of May, the oil plume has reached the Delta.
• Six weeks after the disaster at Deepwater Horizon, the still-uncapped well has caused the worst oil disaster in American history. Contamination has even been found in the Gulf's subsurface waters.
BP created two relief wells to stop the unchecked flow of oil into the Gulf. Officials expected those wells to be completed in August, about four months after the explosion.
To prevent four months of damaging, non-stop releases into the environment (while relief wells were being drilled), experts tried to determine whether temporary measures - such as spreading chemical dispersants and placing a large cap over the leak - could be usefully deployed.
Everyone else can only hope they are successful and that appropriate regulations (not to mention carefully run businesses and federal agencies) will prevent another disaster in the Gulf - or elsewhere. (The last link depicts how the oil spill would appear if the catastrophe had occurred where you live.)
Some experts fear, with apparently good reason, that a huge oil plume could cause trouble underneath the Gulf's surface. Meanwhile, others believe that a formal investigation is likely to place responsibility for the disaster at many different doorsteps.
High on the list of suspects is the blowout preventer. BP recovered it during September, and experts will try to determine what went wrong.
As official investigations continue, BP has already released its report on the disaster. The company includes itself in a blameworthy list.