Sunday, May 2, 2010
The Gulf oil spill is much worse than originally believed.
As the Christian Science Monitor writes:
It's now likely that the actual amount of the oil spill dwarfs the Coast Guard's figure of 5,000 barrels, or 210,000 gallons, a day.
Independent scientists estimate that the renegade wellhead at the bottom of the Gulf could be spewing up to 25,000 barrels a day. If chokeholds on the riser pipe break down further, up to 50,000 barrels a day could be released, according to a National Oceanic and Atmospheric Administration memo obtained by the Mobile, Ala., Press-Register.
CNN quotes the lead government official responding to the spill - the commandant of the Coast Guard, Admiral Thad Allen - as stating:
If we lost a total well head, it could be 100,000 barrels or more a day.Indeed, an environmental document filed by the company running the oil drilling rig - BP - estimates the maximum as 162,000 barrels a day:
In an exploration plan and environmental impact analysis filed with the federal government in February 2009, BP said it had the capability to handle a “worst-case scenario” at the Deepwater Horizon site, which the document described as a leak of 162,000 barrels per day from an uncontrolled blowout — 6.8 million gallons each day.Best-Case Scenario
BP is trying to perform a difficult task of capping the leak by using robotic submarines to trigger a "blowout preventer" 5,000 feet below the surface of the ocean. Here's a photo of the robot trying to activate the switch on April 22nd:
If successful, the leak could be stopped any day. Everyone is rooting for the engineers, so that they may successfully cap the leak.
Already, however, the spill is worse than the Exxon Valdez, and will cause enormous and very costly destruction to the shrimping, fishing and tourism industries along the Gulf Coast of Louisiana and Florida. It will be years before good estimates on the number of dead fish, turtles, birds and other animals can be made.
The Backup Plan
If the blowout preventer can't be triggered, the backup plan is to drill another well to relieve pressure from the leaking well.
Here's a drawing prepared by BP showing the plan (the drilling rig on the left will take months to drill down and relieve pressure from the leaking rig):
Here's a graphic from the Times-Picayune showing the same thing (and accurately showing that there are currently 3 leaking oil plumes):
BP will also attempt to drop concrete and metal "cages" over the leak sites, to try to buy time by collecting oil in the cages, and then draining oil away in a safer manner. As AP writes:
BP PLC was preparing a system never tried before at such depths to siphon away the geyser of crude from a blown-out well a mile under Gulf of Mexico waters. However, the plan to lower 74-ton, concrete-and-metal boxes being built to capture the oil and siphon it to a barge waiting at the surface will need at least another six to eight days to get it in place.In addition, BP is using chemical disperents to try to break up the oil plumes as they arise (the dispersants are highly toxic).
Worst-Case ScenarioAs the Associated Press notes:
Experts warned that an uncontrolled gusher could create a nightmare scenario if the Gulf Stream carries it toward the Atlantic.This would, in fact, be very bad, as it would carry oil far up the Eastern seaboard.
Specifically, as the red arrows at the left of the following drawing show, the Gulf Stream runs from Florida up the Eastern Coast of the United States:
[Click here for full image.]
How could the oil get all the way from Louisiana to Florida, where the Gulf Stream flows?
As Discovery explains:
Many ocean scientists are now raising concerns that a powerful current could spread the still-bubbling slick from the Florida Keys all the way to Cape Hatteras off North Carolina.A graphic from the Discovery article shows what the Gulf loop current looks like:
These oceanographers are carefully watching the Gulf Loop Current, a clockwise swirl of warm water that sets up in the Gulf of Mexico each spring and summer. If the spill meets the loop -- the disaster becomes a runaway.
"It could make it from Louisiana all the way to Miami in a week, maybe less." said Eric Chassignet, director of the Center for Ocean Atmospheric Prediction Studies at Florida State University. "It is pretty fast."
Right now, some computer models show the spill 30 to 50 miles north of the loop current. If the onshore winds turn around and push the oil further south: "That would be a nightmare," said Yonggang
Liu, research associate at the University of South Florida who models the current. "Hopefully we are lucky, but who knows. The winds are changing and difficult to predict."
Imagine the loop current as an ocean-going highway, transporting tiny plankton, fish and other marine life along a watery conveyor belt. Sometimes it even picks up a slug of freshwater from the Mississippi River -- sending it on a wandering journey up to North Carolina.
The Gulf Loop Current acts like a jet of warm water that squirts in from the Caribbean basin and sloshes around the Gulf of Mexico before being squeezed out the Florida Strait, where it joins the larger and more powerful Gulf Stream current.
Oceanographer George Maul worries that the current could push the oil slick right through the Florida Keys and its 6,000 coral reefs.
"I looked at some recent satellite imagery and it looks like some of the oil may be shifted to the south," said Maul, a professor at Florida Institute of Technology in Melbourne, Fla. "If it gets entrained in the loop, it could spread throughout much of the Atlantic."
In fact, new animation from a consortium of Florida institutions and the National Oceanic and Atmospheric Administration, predicts a slight southward shift in the oil over the next few days.
Naval Oceanographic Office
According to ROFFS, the oil spill is getting close to the loop current:
In a worst-case scenario - if the oil leak continued for a very long period of time - the oil could conceivably be carried from the Gulf Stream into world-wide ocean currents (see drawing above).
I do not believe this will happen. Even with the staggering quantity of oil being released, I don't think it's enough to make its way into other ocean currents. I think that either engineers will figure out how to cap the leak, or the oil deposits will simply run out. It might get into the Gulf loop current, and some might get into the Gulf Stream. But I don't believe the apocalyptic scenarios where oil is carried world-wide by teh Gulf Stream or other ocean currents.
Changing the Climate
There is an even more dramatic - but even less likely - scenario.
Specifically, global warming activists have warned for years that warming could cause the "great conveyor belt" of warm ocean water to shut down. They say that such a shut down could - in turn - cause the climate to abruptly change, and a new ice age to begin. (This essay neither tries to endorse or refute global warming or global cooling in general: I am focusing solely on the oil spill.)
The drawing above shows the worldwide "great conveyer belt" of ocean currents, which are largely driven by the interaction of normal ocean water with colder and saltier ocean currents.
Conceivably - if the oil spill continued for years - the greater thickness or "viscosity" of the oil in comparison to ocean water, or the different ability of oil and seawater to hold warmth (called "specific heat"), could interfere with the normal temperature and salinity processes which drive the ocean currents, and thus shut down the ocean currents and change the world's climate.
However, while this is an interesting theory (and could make for a good novel or movie), it simply will not happen.
Because there simply is not enough oil in the leaking oil pocket to interfere with global ocean currents. And even if this turns out to be a much bigger oil pocket than geologists predict, some smart engineer will figure out how to cap the leak well before any doomsday scenario could possibly happen.