[Vision2020] Mystery Bulge in Oregon Still Growing

[Warren Hayman]

I agree-- wow! an intrusive lake of caustic material is upwelling from 
underground, thus disturbing the once-placid surroundings. Thank 
goodness such magmatic zealotry seeking to disfigure (no doubt with a 
rebuttal of "not disfigure, redefine") is as we speak being carefully 
monitored by professionals. I'm sure glad it's happening in Oregon, and 
not the Palouse.

Warren Hayman

On Thursday, September 8, 2005, at 10:32  AM, Pat Kraut wrote:

> Thanks for this new info. Wow! My college professor had move out here 
> to
> teach geology because we had some of the newest activity in geologic 
> time.
> Three day after he got here Mt St Helens blew, he said he felt somewhat
> responsible! He is now at the U of Oregon. I bet he is involved in 
> following
> this or wishes he were.
>
> ----- Original Message -----
> From: "Burt Sid" <sid.burt at gmail.com>
> To: "Vision2020" <vision2020 at moscow.com>
> Sent: Wednesday, September 07, 2005 10:39 PM
> Subject: [Vision2020] Mystery Bulge in Oregon Still Growing
>
>
> http://livescience.com/forcesofnature/ap_050906_sisters_bulge.html
>
>
> Mystery Bulge in Oregon Still Growing
> By The Associated Press
>
> posted: 06 September 2005
> 09:02 am ET
>
>
> 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.
>
> 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.''
>
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> _____________________________________________________
>  List services made available by First Step Internet,
>  serving the communities of the Palouse since 1994.
>                http://www.fsr.net
>           mailto:Vision2020 at moscow.com
> ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
>