Skip to comments.Mystery Bulge in Oregon Still Growing (100 square miles near Mt St. Hellens)
Posted on 09/07/2005 10:35:31 AM PDT by LesbianThespianGymnasticMidget
BEND, Ore. (AP) -- A recent survey of a bulge that covers about 100 square miles near the South Sister indicates the area is still growing, suggesting it could be another volcano in the making or a major shift of molten rock under the center of the Cascade Range.
Recent eruptions at nearby Mount St. Helens in Washington state have rekindled interest in the annual Sisters survey and its findings.
Oregon has four of the 18 most active volcanoes in the nation -- Mount Hood, Crater Lake, Newberry and South Sister. A recent U.S. Geological Survey report said monitoring is inadequate at all of them, with only basic monitoring at about half of the active volcanoes.
The Fury of Volcanoes
Mount St. Helens in 2004
Unlike the volcanoes, the bulge gets an extensive annual survey to track its growth. Spread out across an area nearly as big as the city of Portland, It's centered about three miles southwest of the South Sister, about 25 miles from Bend.
The results of the late August survey won't be ready for weeks, but scientists have reached some conclusions about the bulge from past monitoring.
They say it probably began growing in 1997 and has been rising ever since at a rate of about 1.4 inches a year. It was first observed from space using a relatively new imaging technology known as radar interferometry that can measure changes in the Earth's surface.
The likely cause of the bulge is a pool of magma that, according to Deschutes National Forest geologist Larry Chitwood, is equal in size to a lake 1 mile across and 65 feet deep.
The magma lake is rising 10 feet each year, under tremendous pressure, and it deforms the Earth's surface as it expands, causing the bulge.
Other causes could be anything from the birth of a new volcano -- a fourth Sister in the making -- to a routine and anticlimactic pooling of liquid rock, researchers say.
"The honest and shortest answer is, we don't know,'' said Dan Dzurisin, a USGS geologist.
Dzurisin recently led a three-person leveling crew on a slow walk across the top of the bulge. They were hoping to detect any change in its surface using survey equipment accurate to one-sixteenth of an inch for every mile measured.
Dzurisin's survey data, in concert with space imaging and satellite positioning measurements from two dozen fixed points on the bulge, give scientists an idea of the bulge's depth and size.
Additional information from seismographs and chemical monitoring of area springs reveal movement of the magma underground. A swarm of 350 small earthquakes in March 2004 indicated magma was on the move, but the bulge has been quiet ever since.
Whether the magma will move again or ever reach the surface is a mystery. But if it did, geological history suggests it would result only in small cinder cones that spew ash and lava.
The good news is that such an eruption likely would not seriously affect any population centers, Chitwood said.
Such cones are the most common volcanic features on Earth, he added. Central Oregon has about 600. Basalt flows have occurred in the area of the bulge every 1,000 to 1,500 years for the past 4,000 years, he said. And the area is due for another.
"The bulge is on time,'' Chitwood said. "The bus has arrived.''
He can't beat Dick Cheney.
Cadaver dogs can scent bodies that are under water, and search sites are not often clean and free of other smells. It's just something they'd learn to deal with. Dogs are susceptible to many of the same bacteria we are. I don't know if they are using them now or not. I haven't seen any articles on search dogs in this disaster.
No, it's the weather control devices! (wingnut thinking) /sarcsm
They don't call Oregon "the Big O" for nuthin'.
OMG, I think I tinked.
Your title is wrong; this isn't near Mt. St. Helens, (Which is in Washington State) it's near the Three Sisters in Oregon, a good distance to the South.
The area is 150 miles from Mt. St. Helens, on the opposite side of the Cascade Range. Is that near? Well, in terms of probable simultaneous activity, no.
For heaven's sake! Call FEMA NOW!!!!
Do you know where the buses are?????
Thanks for the ping!
Please notify me via FReepmail if you would like to be added to or taken off the Oregon Ping List.
Ummm.... your subtitle is not very accurate. It's something like a couple hundred miles away.
ya, ya, ya, already been roasted for that, but read the second line of the article.
Could all you marvelous freepers tone it down a bit on this one, please? My ex-wife "earth momma" lives in Bend and I certainly wouldn't want her to be missing out this natual "orgasm". Heheheheh!!!!
Karl Rove is doing this to divert attention from the mess in New Orleans.
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