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OT Mount St Helens Getting ready To Blow

Posted: Wed Sep 29, 2004 1:31 pm
by canegrl04
The lava dome continues to build,and the quakes have begun to get larger (mag.3s),according to someone's report on an earthquake board

http://www.drudgereport.com

Posted: Wed Sep 29, 2004 1:37 pm
by Brent
Yes... it's been in the news for 3 days now. It's not going to be an explosion like 1980, just a small one.

Posted: Wed Sep 29, 2004 4:43 pm
by Anonymous
This could cause a really cold winter like the early 80s when Tallahassee dropped to -1F and there were Icicles in South Ga-As the ash cloud blocks the sun IMHO Correct?

Posted: Wed Sep 29, 2004 6:13 pm
by PurdueWx80
Not correct - Mt. St. Helen's did not cause any noticeable change in climate after the eruption in 1980. It takes a VERY large explosion on a very large mountain to do such a thing, and Helen's isn't capable of this.

Posted: Wed Sep 29, 2004 7:04 pm
by Stormsfury
PurdueWx80 wrote:Not correct - Mt. St. Helen's did not cause any noticeable change in climate after the eruption in 1980. It takes a VERY large explosion on a very large mountain to do such a thing, and Helen's isn't capable of this.


Actually, I'm not so sure about that ... the ash cloud reached 80,000 ft in less than 15 minutes, spread across the U.S. less than 3 days, and circled the Earth in 15 days ... of course, 1980 Summer was exceptionally HOT AND DRY, but how about the cold winters of 81, 82, and 83 ... many, many times even in the Southeast where temperatures fell to the low TEENS (Charleston, SC) ... that's a feat ...

the whole north face bulged and expanded 5 FEET per day until that fateful May 28th, 1980 at 8:32 am ... the north slope collapsed, and actually there were TWO explosions ... the first one was the collapse of the north flank, but the second was from the expanding gases, and steam from the molten rock and set off a chain reaction of explosions.

Image

The ash plume and cloud reached a height of 80,000 ft. in less than 15 minutes, spread across the US in 3 days, and circled the Earth in 15 days...

http://vulcan.wr.usgs.gov/Volcanoes/MSH/May18/summary_may18_eruption.html

Image

Image

Downloadable AVI file of Mt. St. Helens eruption in 1980 (satellite imagery)
http://www1.ncdc.noaa.gov/pub/data/images/mt-sthelens.avi

Posted: Wed Sep 29, 2004 7:12 pm
by PurdueWx80
From another post I made a few days ago:

More than likely, there would be few effects from the type of blast expected - less solar radiation can get to the surface because of all the ash/gas/particles in the air, but it takes a really big explosion to do this. The amount of CO2 and other greenhouse gases released shouldn't be enough to cause a warmup. Here is an article from NASA concerning the effects of the 1980 eruption on climate. I think the NOLA NWS went a little overboard in their statement.

http://www.gsfc.nasa.gov/gsfc/educ/scie ... 050696.htm

Posted: Wed Sep 29, 2004 7:47 pm
by Stormsfury
I stand corrected ...

PurdueWx80 wrote:From another post I made a few days ago:

More than likely, there would be few effects from the type of blast expected - less solar radiation can get to the surface because of all the ash/gas/particles in the air, but it takes a really big explosion to do this. The amount of CO2 and other greenhouse gases released shouldn't be enough to cause a warmup. Here is an article from NASA concerning the effects of the 1980 eruption on climate. I think the NOLA NWS went a little overboard in their statement.

http://www.gsfc.nasa.gov/gsfc/educ/scie ... 050696.htm

Posted: Wed Sep 29, 2004 8:05 pm
by michaelwmoss
If she goes, could this be the beginning of an abnormally active period of "small" eruptions for this volcano?

Posted: Wed Sep 29, 2004 11:54 pm
by Aslkahuna
Actually, it's not the ash that results in cooling but the aerosols blasted into the stratosphere-usually SO2 which forms Sulphuric acid aerosol which works two ways. First it blocks incoming solar radiation and secondly, it plays holy heck with the Ozone layer the combination results in warming at high levels which the atmosphere compensates for by cooling below. Lest one forget, there was a modest (about 5X or so stronger than St. Helens) eruption at El Chicón in Mexico in 1982. As luck would have it, like Pinatubo the Mexican eruption coincided with an El Niño though the 1982-83 El Niño was The Mother of all Niños.

Steve

Posted: Thu Sep 30, 2004 7:34 am
by Miss Mary
I thought Mt St Helens erupted May 18, 1980? I remember that date b/c it's my brother's birthday.....was there then activity for 10 days following the first major eruption, from the 18th until the 28th?

Mary

PS - self edit....it was 5.18.1980. Found several sites for Mt St Helens, such as this one:
http://www.fs.fed.us/gpnf/mshnvm/

Posted: Thu Sep 30, 2004 7:35 am
by Brent
Jekyhe32210 wrote:This could cause a really cold winter like the early 80s when Tallahassee dropped to -1F and there were Icicles in South Ga-As the ash cloud blocks the sun IMHO Correct?


January 1982 produced record cold down here... single digits. Summer of 1980 was record heat though.

Posted: Thu Sep 30, 2004 3:19 pm
by michaelwmoss
It was the day before my 5th birthday when she blew

Posted: Thu Sep 30, 2004 5:00 pm
by Stormsfury
Miss Mary wrote:I thought Mt St Helens erupted May 18, 1980? I remember that date b/c it's my brother's birthday.....was there then activity for 10 days following the first major eruption, from the 18th until the 28th?

Mary

PS - self edit....it was 5.18.1980. Found several sites for Mt St Helens, such as this one:
http://www.fs.fed.us/gpnf/mshnvm/


Nice catch, and a major typo on my part ...