91av

OIL pipelines in southern Alaska could be ruptured by a massive earthquake in
previously unrecorded geological faults, an Alaskan geologist warned this week.
A quake here could trigger an environmental catastrophe worse than the oil spill
from the Exxon Valdez tanker in 1989, he says.

“There is the potential for a major disaster because of the oil pipelines and
stores in the area,” Peter Haeussler of the US Geological Survey in Anchorage
told 91av. His warning follows the release of secret
geological surveys carried out by oil company ARCO Alaska over the past 40
years. The company let Haeussler and his colleagues use the survey data to
construct the first complete maps of faults beneath the Cook Inlet, south-west
of Anchorage.

Cook Inlet is the oldest oil producing area in Alaska. There are 17 oil
platforms dotting its waters, tapping oil trapped in geological folds below the
inlet. When Haeussler examined the seismic data he found that the folds
contained fields of faults that have not been noticed before. “They are probably
still active. Quakes could occur right in the oil area,” he says.

Haeussler found 22 shallow faults, each capable of producing a quake every
few hundred years. He says the folds in which the faults occur look very like
those that caused the destructive 1994 earthquake in southern California and
those that killed 5000 people in Kobe, Japan, in 1995.

The inlet’s oil platforms are probably safe, says Haeussler. They are
securely anchored to withstand collisions with huge chunks of ice that float
into the inlet in winter. But the pipelines, constructed along the bed of the
inlet to carry oil to onshore refineries, are not nearly so well anchored, he
warns. “The pipelines are the weak link in the chain. Some of them might rupture
in a quake.”

Alaska has a history of major earthquakes. Its largest city, Anchorage, was
levelled by a quake of magnitude 9.2 when tectonic plates shifted some 40
kilometres beneath the city on Good Friday, 1964. These new folds could produce
quakes of 6.9 or more, says Haeussler. Though unlikely to be as strong as the
Anchorage quake, they could be just as destructive, being nearer the
surface.

Cook Inlet is less than 100 kilometres from Prince William Sound, where the
Exxon Valdez ran aground, causing lasting ecological damage and a billion-dollar
clean-up bill. Despite the activities of the oil industry, the inlet remains
“one of the richest and most biologically diverse estuaries on the planet”,
according to the EcoJustice Network, which represents native communities opposed
to the oil industry there.