The oil-spill response workers in the Gulf of Mexico are poised to conduct a controlled burn of the oil leaking from the Deepwater Horizon well. Offshore burning can prevent oil from reaching shorelines.

In fact, about 90-98 percent of the oil can be removed from the water by burning, leaving behind a waxy residue that can be skimmed from the surface.

The process is time-tested and quite effective. Since oil is lighter than water, it rises to the surface where it is exposed to oxygen. Response vessels surround portions of the spill using fire-retardant booms, and a device called a fire-starter is used to touch off a controlled fire. The flames produce a plume of dark smoke, but the oil is consumed, greatly diminishing the likelihood of shoreline impacts.

Meanwhile, BP's efforts to use ROVs to close the valves in the blowout preventer are continuing.

The graphic below produced by BP shows the situation below the surface of the water, including the position of the bent drill pipe (riser), the blowout preventers (BOPs) both for the existing well and for a proposed relief well, the ROVs, and the location of the Deepwater Horizon drilling rig which sank last week.

More information is expected to be released tomorrow about the outcome of the controlled burn and the efforts to stop the leak.