Will South Sister Erupt? USGS Says Not Soon But They're Watching

SOUTH SISTER VOLCANO, OR — When people in Oregon think about volcanos and threats, their minds tend to wander across the Columbia to Mount St. Helens. Or they stay a little closer to home and think about Mt. Hood and its regular earthquake swarms.

The United States Geologic Survey is now saying it wouldn't hurt to also pay attention to South sister Volcano, one of the Three Sisters.

Scientists from the USGS have been set up GPS monitors just west of south Sister to measure what they call "uplift." That's the term for when there's a rise in the ground.

"We think it's important to monitor this one as carefully and thoroughly as we can for as long as it goes on," USGS Geologist Dan Dzurisin said.

Dzurisin cautions that while the the land is rising and it could very well be magma pushing its way to the surface, and the bulge is 10 miles across, there's nothing to worry about right now.

He says that the uplift has "been going on for 25 years and still goes on today."

That the uplift is likely being caused by magma rising is what has them paying close attention.

The last eruption in Oregon was around 2,000 years ago and was in the area by South Sister.