1 p.m. Friday update: The Alaska Volcano Observatory lowered its Redoubt volcano alert level to orange and "watch" from red and "warning" late this morning after three days passed without a major explosion.
In its most recent advisory, issued at 11:44 a.m., the observatory said the intensity of Redoubt's activity has declined over the last few days even as it remains in an active eruption phase "characterized by continuous emission of steam, volcanic gas and variable amounts of ash."
5 a.m. Friday update: There have been no significant changes at Mount Redoubt overnight. Small earthquakes continue on the mountain at the rate of three to four per minute, according to the Alaska Volcano Observatory. No ash advisories are in effect. The alert status of the volcano remains "red/warning."
With storage space for Cook Inlet oil running critically low and Redoubt volcano continuing to rumble upstream from an active tank farm, officials said they have given a tentative OK for a ship to take on 6.3 million gallons from the Drift River oil terminal. At a news conference Thursday, Coast Guard Capt. Mark Hamilton said the Seabulk Alaska will dock Saturday at the Christy Lee platform, the offshore loading facility for the Drift River terminal. The oil will come from the 6 million gallons already stored there and from oil piped from facilities at Trading Bay and Granite Point.
When it's finished loading two days later, about 840,000 gallons of crude will be left in each of two active tanks at Drift River, a facility built 42 years ago downriver from Redoubt volcano. That's the minimum that can be safely and economically left there, Hamilton and other officials said.
The terminal, an essential component of the Cook Inlet oil-production system, has been the single most affected industrial site in the current eruption cycle of Redoubt, now nearing the end of its second week. Gary Folley of the Alaska Department of Environmental Conservation said officials remain concerned about the risk of a massive oil spill into Cook Inlet, but reducing the amount stored there to about a fourth of the current amount is a big improvement, he said.
The tank farm was built in the floodplain of the Drift River, which is fed by glaciers and icefields flanking the volcano 22 miles away. Eruptions and flows of hot gases, mud and rock can quickly melt massive amounts of ice, sending flash floods down the river. A dike has so far sheltered the tank farm, but officials don't fully trust it even though it has weathered several flash floods in recent days without damage.
The volcano continues to simmer, said Chris Waythomas, a scientist with the observatory. The last major explosion was Tuesday, but it continues to eject a steady if small stream of ash and dust into the atmosphere, creating a light haze over the Cook Inlet region.
Rhythmic seismic tracks confirmed by visual sightings show the volcano is building a dome from lava hardening at the surface of its crater, Waythomas said. The dome is hot, more than 900 degrees Fahrenheit, he said.
Domes are typical of an eruption cycle at Redoubt and other volcanoes like it, he said.
What's also typical is that domes become unstable and break apart, sometimes accompanied by an explosive release of ash into the atmosphere, Waythomas said. The debris falls rapidly down the flanks of the volcano, sucking hot gases and ash with it. When the material hits an icefield or glacier, the melting is immediate and dramatic -- hence the concern at the Drift River terminal, about a two- to three-hour journey for a wall of floodwater.
After it collapses, the dome can be expected to build again. The situation can go on for months, Waythomas warned. In the mid-1960s, it went on for years at Redoubt.
OIL TRANSFERS HALTED
The Drift River terminal was evacuated after the current eruption cycle began March 22. That put a halt to oil transfers to Drift River from intermediate facilities at Trading Bay and Granite Point. Those facilities are near capacity, Hamilton said, and some platforms have already been forced to shut down.
Hamilton, the federal on-scene coordinator for the region and one of three representatives in the unified command dealing with the oil-spill threat from Drift River, said officials are taking into consideration the impact of a shutdown on the economy of the region. But he said the transfer will only begin Saturday if it can be done safely.
Oil in the Drift River tanks will have to fall and rise during the loading operation to accommodate the pumping equipment and pipelines, but will never be allowed to rise above the current level of 3.1 million gallons in each tank, he said.
Crews will have to be on hand at the terminal and platform to perform the operations. Pumps and the terminal's power plant appear to be operating normally, and the pipelines connecting it with the other facilities and the offshore shipping dock will be tested before loading operations begin, said Hamilton and Rod Ficken, vice president of Cook Inlet Pipeline Co., which owns the facility.
Among the extraordinary safety precautions that will be put in place Saturday: a National Weather Service official will be assigned to closely monitor conditions in the immediate vicinity of the loading dock, a mile off shore.
Ficken said his first concern is for the safety of crews who will run the pumping operation. In the event of a sudden eruption or dome collapse, the crew can shut down operations in an hour or less. If they can't make an escape in a helicopter, there's an emergency shelter at the site capable of withstanding flood and ash, he said.
Hamilton and Folley said enough oil spill containment and clean-up equipment is on hand or nearby to deal with a likely spill.
Once the tanker leaves with its load, officials will then go to work to figure out what to do next. Normally, a tanker calls on Drift River about every 30 days to take oil to the Tesoro refinery in Nikiski, Ficken said.
Representatives of the Coast Guard, the DEC and Cook Inlet Pipeline Co., operating as a unified command for Drift River, announced a community meeting for Kenai Peninsula residents on April 7 to discuss the oil terminal. The meeting will start at 6 p.m. at the Challenger Learning Center in Kenai and will be hosted by the Cook Inlet Regional Citizens Advisory Council.
Find Richard Mauer online at adn.com/contact/rmauer or call 257-4345.More volcano coverage
By RICHARD MAUER