There have been a few new developments regarding the oil spill. Unfortunately, a stop to the spill is not one of them, at least not yet. The latest proposal to reduce the spill is to position a "top hat" over the leaking riser pipe. The "top hat" is smaller than the containment chamber that failed last week. As with the containment chamber, no one can be sure that this will work until the "top hat" is actually in place. An image of the device is below. Another possible solution is an insertion tube.
The "top hat" on the deck of the motor vessel Gulf Protector / Photo courtesy Deepwater Horizon ResponseMore dead marine animals have washed up on beaches. As the BBC link mentions, six dead dolphins have appeared on shore. Tissue samples have been sent to a laboratory for testing; pending the results, the National Marine Fisheries Service is treating them as likely victims of the spill. In addition, hundreds of dead fish showed up on a beach in Alabama. As with the dolphins, the cause of death is so far unknown, but the mass fish kill is unusual enough that it may be connected with the spill. Some of the dead fish are very large.
The House Subcommittee on Oversight and Investigations has been holding hearings this week to investigate the cause of the explosion and the attempts to stop the leak. The various companies involved have each tried to blame the others, so it may be some time before we have an accurate idea of what happened. For now, the House panel is blaming the blowout preventer, a device that regulates the flow of oil to the riser pipe. In case of an accident, the blowout preventer is supposed to cut through the pipe and stop the flow of oil. The company that placed the device provided BP with incorrect diagrams of the blowout preventer; this may explain why the undersea robots were unable to activate it. The well had also failed a pressure test on the day of the explosion:
It passed one set of so-called positive pressure tests in which fluids were injected into the well to increase pressure to monitor whether the well remains stable.There is some possibility that the explosion and spill will result in criminal charges for one or more of the companies involved. Criminal charges, if they result in a conviction, would help the government recoup more of the cost of the damage and cleanup from the companies involved. Currently civil liability is capped at $75 million, but criminal charges have no such penalty cap. Laws that could have been violated include the Clean Air and Water Acts and the Migratory Bird Treaty Act. Various other laws could also apply.
It failed, however, a negative pressure test, in which fluid inside the well is reduced to see whether gas leaks into the well through the cement or casing....
Another test showed high pressure in the main well pipe but zero pressure in two other connecting lines, a sign, Waxman said, that gas was leaking into pipe.
What happened next, Waxman said, is "murky." BP attorneys say the well passed subsequent tests and at 8 p.m. the company resumed removing heavy and costly drilling lubricants known as mud from the well.
The well blew about an hour and a half later when a huge mass of methane gas burst up the pipe, engulfed the rig and exploded into flames.
BP finally released a portion of its video of the oil leak after much pressure from the government and media. Here is a short snippet, which I found via Treehugger.
Finally, The Boston Globe has a gallery of large images from the spill and its aftermath. You can keep up with news about oiled birds at the International Bird Rescue Research Center's blog.