03/18/2010 05:12 am ET Updated May 25, 2011

North Slope Oil Spill: Leak In Alaska Among Worst Ever (PHOTOS)

AP reports on a massive oil spill on the North Slope -- among the worst ever in the region:

A North Slope spill of an estimated 46,000 gallons was caused when a pipeline ruptured lengthwise along the bottom, creating a 2-foot-long opening.

A unified command of officials handling the spill say the rupture along the bottom of the 18-inch pipeline was caused by too much pressure in the line, likely caused by ice plugs.

The spill of crude oil, mixed with natural gas and water, occurred more than a week ago in the Lisburne field just north of the Prudhoe Bay oil field. The pipeline was not in operation at the time. When it ruptured, residual material spilled on to the tundra.

A visual inspection of the BP-operated line was delayed until it was completely depressurized. Inspectors got a look at it Monday. It is no longer leaking.


Spill Is Among Worst Ever On North Slope
Spill Is Among Worst Ever On North Slope

"The Anchorage Daily News" has more details of the spill, including this tidbit about the criminal charges BP faced after the biggest North Slope spill ever.

The biggest oil spill ever on the North Slope occurred in 2006 when more than 200,000 gallons of crude leaked from a corroded transit line at the Prudhoe Bay field. That led to a criminal misdemeanor conviction for BP, $20 million in fines and restitution, and three years of probation, which the company is still on.

Get HuffPost Green On Facebook and Twitter!