Oil Spill in Gulf of Mexico: in Maps and Graphics

massive oil leak in the Gulf of Mexico is slowly starting to reach the shore, according to reports.

Up to five thousand barrels a day are thought to be leaking from the site of the Deepwater Horizon rig which sank on 22 April after an explosion in which 11 workers lost their lives.

The delicate eco-system of the gulf coastline is rich in wildlife including the brown pelican, many species of duck, turtles, and whales.

There are fears that the disaster could reach the scale of the 11m gallon Exxon Valdez spill off Alaska in 1989.

TACKLING THE OIL SLICK

Emergency oil response teams are using several methods in attempts to deal with the oil at the surface.

More than 41 miles of floating boom is being used to contain the oil, with 58 miles on standby.

Skimmers, which skate over the water, brushing up the oil are also being employed and more than 20,300 barrels of oil-water mix have been removed.

Dispersant chemicals, rather like soap, are being sprayed from ships and aircraft in an effort to help break down the oil - which is also degraded by wind and waves.

Burning is another method sometimes used to tackle oil spills although it can be tricky to carry out and has associated environmental risks such as toxic smoke.

On Wednesday, response teams carried out a test burn of a patch of oil, close to where the rig sank.

A spokesman said the test was successful but that the team were "evaluating conducting additional burns".

UNDERWATER EFFORTS

Five thousand feet (1,500m) below the surface, four robotic submersibles have been in almost constant operation, trying to activate the blow-out preventer, a set of huge valves designed to seal the well.

Experts believe the blow-out preventer (BOP) must have partially triggered otherwise the flow of oil to the surface would be more extreme than it is.

However, the remotely operated vehicles (ROVs), as they are known, have not yet been successful in further activating the BOP and it is unclear whether this is now possible.

The next course of action is to lower a giant "dome" over the site to funnel the oil to the surface and dispose of it there.

BP, which owns the well, is already building the structure but it will take several weeks to construct and has not been tried at such depths before.

A long-term solution is also in progress - drilling a relief well which can tap into the leaking well and take the oil.

However, BP warn that it could be up to three months before this is operational.