Deepwater Horizon: overview of a catastrophe
The Deepwater Horizon oil rig exploded on 20th April, killing eleven workers and injuring seventeen more. The well which it had been drilling was in water over 1.5km deep and descended another few kilometres into the sea floor into an oil field estimated to contain about 50 million barrels of oil (enough to supply the world's needs for less than a day, by the way). After the explosion, oil started gushing from the well into the deep waters of the Gulf and has continued to do so until today, over one month later.
After initially claiming that the oil slick on the surface was just from the sunken rig and not from the well, BP then offered an first estimate that about 1,000 barrels a day were leaking. This was revised up to 5,000 barrels a few days later by NOAA (National Ocean and Atmospheric Administration) and has remained the official government estimate. Scientists analysing the size of the visible spill on the surface put the figure at around 20-25,000 barrels a day, though this ignored the significant amounts of dispersant that BP was pumping into the oil as it exited the well (causing much of the oil to never make it to the surface) and the enormous oil slicks, some 10 km long, floating well below the surface.
Critics of BP started to point out numerous problems in their response, including their use of inferior and more toxic dispersants purchased from a company linked to BP (they have recently been ordered to find a less toxic alternative, having already employed 3 million litres of the stuff) and perhaps of greater concern, a pattern of trying to hide or minimise the extent of the problem. Under pressure, BP finally released some video footage of the underwater oil eruption, from which independent scientists estimated the flow rate at up to 70,000 barrels per day. More pressure from Senators lead to BP posting more videos, from which it has been estimated that it may be closer to 100,000 barrels per day, of which BP have now managed to siphon off up to about 5,000 barrels per day via a pipe they have managed to thread down the gushing hole. That is, it appears that the disaster is one hundred times greater than they first admitted. It is already the largest oil contamination in US waters and is moving up the charts towards the largest in the world. About one fifth of the waters in the Gulf are now off-limits to fishing and some of the oil has been caught in the Loop Current, pulling it towards Florida and the lower eastern states.
Tony Hayward, CEO of BP has been quoted calling the 38,000 square kilometres of visible surface spill "a drop in the ocean" when compared to the enormous volume of water in the Gulf. Despite numerous apparent serious breaches of safety protocol and a history of pollution infractions from the rig, he has called the disaster "unforseeable" and "inconceivable" and assured people that the environmental damage is likely to be "very, very modest".
This is not an oil leak, which sounds slow, nor an oil spill, which implies that the oil is pouring from a tank of a given size. This is an ongoing underwater oil gusher, filling an olympic swimming pool every four hours or so. Although efforts to stem the flow are ongoing, ultimately, it may not be stopped until a relief well is drilled, which is likely take a few months. Many commentators are beginning to suggest this may turn out to be the largest environmental catastrophe in US history.
Our dying oceans
However, this is just one of a number of deeply troubling problems facing the world's oceans, and despite potentially affecting the Gulf of Mexico for years to come, its effects are dwarfed in both scale and long term impact by a range of other threats to ocean life: acidification (from carbon dioxide), plastic pollution - including a floating garbage patch possibly larger than Australia, dead zones from agricultural run-off (the oil pollution is likely to exacerbate this problem in the Gulf of Mexico), warming causing coral bleaching, thermal stratification and other changes in marine life, indiscriminately destructive fishing techniques (trawling and dredging) and overfishing, global fish catch peaked in the 1980's and on current trends all commercial fish stocks will likely be depleted (unprofitable or extinct) in the next few decades.
For the authors of holy scripture, the ocean was a terrifying chaos, filled with monsters and a symbol of destruction. The vision of the new heavens and new earth in Revelation 21 includes the telling phrase "and the sea was no more", indicating an end to chaos and destruction.
But today, the picture is reversed. Our oceans are threatened and dying. It is we who are the chaotic (or perhaps all too systematic) destroyer.
Friday, May 21, 2010
Deepwater Horizon: overview of a catastrophe