Thursday, July 01, 2010

What Will Happen to All that Oil From the Gulf Oil Spill?

Some of the oil that has gushed into the Gulf of Mexico is being reclaimed by BP. The rule of thumb seems to be that if it has turned red, the oil is too "weathered" to be commercially viable, but if it's still black it may be salvagable with processing.

In a gigantic rescue effort, a small amount of the oil has been brought ashore manually - by boats and by people bending over and picking it up off beaches. The oil in liquid form will be put in injection wells, while contaminated solid waste will go to special landfills.

As part of the cleanup effort, some of the oil on the surface of the water has been set on fire.

The Automated Data Inquiry for Oil Spills predicts that about 35 percent of the remaining oil will evaporate, about 20 percent will find its way to the ocean, and roughly half will remain in the Gulf of Mexico - some on the surface and the rest dispersed throughout the water.

The oil that goes to the ocean will round the tip of Florida and then probably get caught up in the northward-flowing Gulf Stream. Simulations predict that that oil will flow close to the coast of North America.

The Gulf Stream eventually finds its way to the Norwegian Sea, where the cooled water becomes heavy and sinks to the bottom of the ocean. The trip from Florida to the sink will take about 18 months (based on this analysis of how long ashes dumped in Fort Lauderdale will take to get to England). After sinking in the Norwegian Sea, the Gulf Stream waters flow back south and reappear in the Pacific about 1,600 years later.

Some or all of the oil in the Gulf Stream will drop off en route. Tar balls may wash ashore. The oil may foul beaches and fisheries all up the east coast, although the simulations predict it will veer offshore long before Canada. Some of the oil will disperse in the Atlantic or sink to the bottom - which is reputedly already littered with tar balls from other oil spills and from chronic oil leakage from practices like dock degreasing.

A hurricane, tropical storm, or even plain old high winds could cause several problems.

High winds could dislodge or destroy the booms that are containing some of the oil, causing the slick to spread further. They would also likely cause large waves that will drive more oil ashore.

Storm surge could drive contaminated water up canals and rivers. (It was storm surge that caused the flooding of New Orleans in the hours and days after Katrina.) A major concern in New Orleans is that the contaminated water will reach Lake Pontchartrain.

The oil itself is a deadly carcinogen, and the tons of dispersants that have been dropped on the slick make it even more toxic. It might seem insane to add more poisons to the mix, until we get to the next hurricane problem - which requires that we get oil off the surface as quickly as possible, and which is the reason for the dispersants.

The biggest concern about hurricanes is that the toxic mess will be picked up by the wind and carried inland. It could be carried hundreds or even thousands of miles before it's dropped on crops and pastures (from which it will spread throughout the food chain) and it will contaminate lakes, rivers, reservoirs and the rest of the water supply.

Of the oil that remains in the Gulf, some will stay in the water forever. Some of it will seep onshore, especially into the salt water marshes that stretch inland for a hundred miles in places. Hurricanes, storm surges and other forces of nature will continue to carry it further inland, possibly for decades to come.

Many people seem to think that BP can pay the costs of the oil spill's damage, but this is way too big for a single company to cover.

(The comic is from xkcd.)


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TVTT said...
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