Redoubt volcano exploded Saturday morning with its biggest eruption yet, spewing ash 50,000 feet high and unleashing a flash flood through the Drift River to the oil terminal, where 11 workers were forced to hole up in a "safe haven."
Flood waters lapped over a power generator, forcing at least a two-day delay in plans to offload millions of gallons of oil from the terminal, the U.S. Coast Guard said.
The latest eruption came just before 6 a.m. The Weather Service issued an ashfall alert for the western Kenai Peninsula and residents reported that significant amounts of ash fell in Homer, Nikiski, Clam Gulch, Seldovia and elsewhere in that area of the Peninsula.
"It kind of looks like snow, only it sucks a lot more," said Becky Brewer, a line cook at Fat Olives restaurant in Homer. "I think I had about a quarter inch of ash on my truck this morning."
It's Homer's second ash fall in as many weeks and business quadruples every time this happens, said Jeff Grant, who manages a local car wash.
Increasing northerly winds continued to stir up the ash Saturday afternoon after the volcanic cloud passed, especially around Kachemak Bay. The Weather Service suggested people limit their outdoor activity while the ash is blowing.
The explosive eruption lasted about 30 minutes, "making it a bit longer and perhaps larger than any of the explosions we've seen thus far in the 2009 eruption," said Margaret Mangan, a geologist with the U.S. Geological Survey. It may be nearly as large as the biggest explosions seen during Redoubt's 1989 and 1990 eruptions, she said.
The eruption delayed at least until Monday efforts to unload some of the oil at Drift River and from Trading Bay and Granite Point, where oil storage is reaching capacity and threatens to shut down production from offshore platforms on the west side of Cook Inlet.
At a news conference Saturday afternoon, Rod Ficken, vice president of Cook Inlet Pipeline Co., the owner of the Drift River facility, said none of the workers at the terminal was injured, no oil was spilled and no water entered the tank farm area. He said there were several ways the company could communicate with workers on scene, but wouldn't describe them.
He said workers were not allowed to talk to the news media.
Speaking for the Alaska Volcano Observatory, Mangan said a slurry of hot ash, rocks and other debris came down the Drift River after the eruption. The terminal, built in the floodplain of the Drift River 42 years ago, was protected once again by a concrete-clad dike designed to hold back the waters from the tank farm.
But late Saturday, Coast Guard officials said they learned the water got into an industrial building at the terminal, damaging a generator necessary to transfer the oil. The repairs will push the project back until Monday at the earliest, said spokeswoman Sara Francis.
Ficken said the emergency shelter was near the flooded airstrip, which is outside the dike. The shelter was built at the same time as the dike, in 1990, to withstand severe flooding. He described the haven as a tall gravel pad -- almost like a tower -- with hardened shields that extend below the surface to prevent erosion in a flood. At the top of the pad are emergency living quarters with an independent supply of water, power and food.
The shelter has a bathroom with several stalls, a kitchen and entertainment room, a pool table, exercise equipment and DVDs, wrote Santana Gonzalez, a Cook Inlet Pipeline Co. spokesman.
Workers over-nighting at the site since the eruption began two weeks ago are required to sleep in the shelter, Ficken said.
The oil terminal is about 22 air miles from the volcano -- a journey that can be covered in two to three hours by a flash flood.
Gary Folley of the Alaska Department of Environmental Conservation, the state's on-scene coordinator, said the flood waters were already receding.
A tanker had moved into the area to offload millions of gallons of oil from the Drift River tanks today, Folley said, but fled the area when the eruption occurred. He said the vessel is now to the south, near Mount Augustine, another active -- though quiet -- Cook Inlet volcano.
Capt. Mark Hamilton of the Coast Guard said the ship, which he identified as the Seabulk Arctic, passed through the ash cloud but was not damaged.
Meantime, two spill response barges were heading as a precaution from Seldovia to the Nikiski area, where they'd be closer to the oil terminal, according to the Coast Guard.
Air traffic in and out of Anchorage has been operating normally.
Saturday morning's blast came a day after the AVO lowered the threat level from "warning" to "watch," because Redoubt activity had quieted.Video: Geologist describes Redoubt's biggest eruption this year
More volcano coverage
By RICHARD MAUER and KYLE HOPKINS
Anchorage Daily News