Alaska: Oil spill after quake unsettles sunken ship

"Our main goal is to ensure we don't have some type of catastrophic release," said a state official. Photo / AP

A ship that sank off Kodiak Island four decades ago has started to leak diesel fuel, and a state official suspects ground shaking from last month's massive magnitude 8.2 earthquake might be the reason.

The vessel sank in 1989 in Womens Bay, "and it's been resting there since", Jade Gamble, the state's on-scene spill coordinator, told CoastAlaska.

The first reports of an oil sheen came in a week after the July 28 earthquake, the largest in the US in the past half-century. It's not clear how much diesel fuel or other contaminants remain on the Saint Patrick.

The 42-meter former scallop boat was hit by a rogue wave in November 1981 near Marmot Island. The crew of 12 abandoned ship and only two survived. The vessel eventually was towed to Womens Bay, where it later sank.

"They've been able to minimise the leak," Gamble said. "Our main goal is to ensure we don't have some type of catastrophic release."

An official at the Alaska Earthquake Center said it's not clear if the quake is responsible for the ship's leak, however. The epicenter was about 420km southwest of Womens Bay.

Despite its size, the quake didn't cause serious damage or produce a major tsunami.

"Kodiak didn't experience anything significant," seismologist Natalia Ruppert said. "And this shipwreck being even farther away from the earthquake source, I guess it's possible."

The ship sunk of Kodiak Island in 1981 after being hit by a rogue wave. Photo / AP

There have been other major earthquakes that were much closer to Womens Bay that would have produced stronger ground shaking, Ruppert said.

"Maybe it was a cumulative effect of these multiple earthquakes that over the years kind of reached a critical stage — it's just hard to tell."

The Coast Guard confirmed the sheen in an August 6 flyover, and it said a contractor is on the scene assisting with the containment.

The Oil Spill Liability Trust Fund has been activated because the Saint Patrick doesn't appear to have an owner, the Coast Guard said.