Updated

The Mount Redoubt volcano in Alaska has had another large eruption after being relatively quiet for nearly a week. This is the 19th major eruption in the last two weeks.

The Alaska Volcano Observatory in Anchorage says the volcano about 100 miles southwest of the city erupted early Saturday.

• Click to view photos of the volcano | Map of Mount Redoubt

The National Weather Service said radar indicated a plume of volcanic ash rose 50,000 feet into the sky, making this one of the largest eruptions since the volcano became active on March 22.

The ash cloud was drifting toward the southeast and there were reports of the fine, gritty ash falling in towns on the Kenai Peninsula.

Meanwhile, a plan is under way to draw down millions of gallons of oil stored in two tanks near Mount Redoubt.

• WEBCAMS: Monitor Alaska's volcanoes live.

The volcano began erupting on March 22. Since then, it has produced numerous large explosions that have sent mud and rock cascading down its flanks. Some of that mud and debris has reached the Drift River Terminal, 22 miles away from the volcano.

That has led to concerns that the terminal, where more than 6 million gallons of oil is stored in two tanks, could be damaged and there could be a catastrophic oil spill that would damage Cook Inlet's valuable fisheries.

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The Coast Guard said again Thursday that a concrete-enhanced dike surrounding the 42-year-old, Chevron-operated terminal is doing a good job of protecting the tanks.

Plans now are under way to draw down some of the oil in the two tanks. The facility's other five tanks are not in use.