Battered by rough seas, a breached tanker begins to sink...
The Prestige was built in Japan in 1976 and was scheduled to be phased out in 2005. The tanker was carrying 84,849 tons of heavy fuel oil, bound for Singapore
NOV. 5-12 Tanker sails from Latvia, passing Spanish coast
NOV. 13 Flooding begins; crew evacuated
NOV. 14 Spain won't allow ship to approach coast and forces it out to sea
NOV. 15 Breach opens in vessel, which is towed to calmer waters
NOV. 19 Tanker breaks in two and sinks
HOW THE SHIP SANK
1 When the oil was loaded, two tanks on each side of the ship were left empty for stability. On Nov. 13, the two starboard tanks became flooded. It is unclear how that happened, but some crew members claimed the vessel struck a submerged object
2 Because of the flooding, the ship began listing 25° to starboard, increasing the stress on the hull
3 To correct the list, the crew flooded the portside tanks, but the increased load was too much for the hull, which began to crack open in heavy seas
ENDANGERED ECOSYSTEM Currents and winds have carried the slick through coastal fishing grounds and across nearly 200 miles of shoreline. The sludge has coated hundreds of seabirds and closed local fisheries. Now other areas are threatened: shellfish beds and a nature preserve for marine birds, including the near extinct Iberian guillemot
... sending nearly 3 million gallons of oil toward the coast ... The choppy waters of the Atlantic quickly spread the oil, making containment impossible. Preventing further damage and restoring the gunk-coated coast are now Spain's biggest challenges. Here are some cleanup methods:
CONTAINMENT Floating barriers are placed around the oil out at sea or along a shoreline to contain the mess. In rough seas, however, these barriers are useless. Chemical gelling agents could be used to help thicken the slick and make it more manageable
SKIMMING Vessels equipped with skimmers recover the oil from the surface of the water. Onshore, workers with shovels take up the tedious work of scooping up the sludge, along with any oily sand and debris from the beach
SOLVENTS On gravel beaches, where oil sinks and rises with the tide, aggressive microorganisms can be used to help break down the oil and disperse it. Biodegradable chemicals such as water-soluble soap are even more effective. Long term, a combination of enzymes, organisms and nutrients can accelerate the oil's degradation
BURNING On-site burning can be done only in open water, where it would pose little danger to the shoreline. The oil is first corralled with booms and then ignited--though getting oil in water to burn is difficult. A big downside: air pollution
... and trapping still more oil on the ocean floor
TWO MILES DOWN
Oil has never been salvaged at this depth before. Some experts believe that trying to recover the oil would be more dangerous than just leaving it. Since the frigid water will thicken the already highly viscous fuel oil to the consistency of tar, it is unlikely to move anywhere soon. No plans have thus been announced--at least not yet--to try to recover the tanker's 18 million gallons of oil. If the contents leak to the surface, the spill will be twice the size of the 1989 Exxon Valdez disaster