Mt. St. Helens

[FSPilot 0]

So if you just break through the crust you can get to the creamy center?

[bmgarcangel 0]

Not really anymore...like the scientist said on the news today, the magma fresh below our surface is too cold to move as smoothly as it might have used to around these parts.

By the way, its going to have its major eruption soon...keep close to the news....

Oh ya, and Mt Hood had a major earthquake last night...almost a magnitude 3....

~Bmg

[Daddl 10]

Mount St. Helens emits cloud of ash(msnbc)

Quote[/b] ]Mount St. Helens released a towering plume of ash Tuesday, its most significant emission in months but one that seismologists did not believe heralded any major eruption.

The volcano has vented ash and steam since last fall, when thousands of small earthquakes marked a seismic reawakening of the 8,364-foot mountain.

Late afternoon television footage showed the plume billowing thousands of feet into the air, then drifting slowly to the northeast.

The ash explosion happened around 5:25 p.m., about an hour after a 2.0 magnitude quake rumbled on the east side of the mountain, said Bill Steele, coordinator of the Pacific Northwest Seismograph Network at the University of Washington.

It might not be the big bang expected last autnum - but that smoke column is pretty impressive I'd say!

[Silent N Deadly 0]

Not really anymore...like the scientist said on the news today, the magma fresh below our surface is too cold to move as smoothly as it might have used to around these parts.

By the way, its going to have its major eruption soon...keep close to the news....

Oh ya, and Mt Hood had a major earthquake last night...almost a magnitude 3....

~Bmg

Mt. Hood had a earthquake? What?

Where did you hear this? I never heard about it.

[Daddl 10]

Mt. Hood had a earthquake? What?

Where did you hear this? I never heard about it.

Uhm, look at the date of the post you quoted... ;)

I just revived the thread to add the latest St Helen eruption that was on the news today.

Btw: as we have (had?) some forum people living in the area: did anyone see the eruption? What has been the situation during the last months?

[Acecombat 0]

I'd hate to be the one living there with the responsiblity of dusting

That ash cloud is enormous , must be like 10 kms high atleast?

[shinRaiden 0]

Actually peaked about 30km I think then dissipated. Basically just a big gas burp that shuffled the pile. I'm about ~110km north, but there's good deal of terrain between here and there. I was curled up with a good book reading up on LDAP systems design so I didn't notice anything until my dad mentioned the report on his way home from work.

This shows the relative postion of Mt. Saint Helens. I'm ~45km SE of Seattle (bottom left corner of picture) and ~110km NNE of St. Mt. Helens. The block to the right of the mountain is Portland, Oregon. The wind currents carried the ash cloud in the same manner as the 2004 and 1980 eruptions mostly due east between Mt. Rainier on the left of the red arrow and Mt. Adams on the right of the arrow, dropping anywhere from Yakima at the edge of the brown area to the state of Montana, as much as ~800km to the east.

Rivers are blue, interstate highways are red. When the I-5 highway was built, the bridge over the Toutle River (drains north side of Mt. Saint Helens) was minimally constructed as the river at that location was historically rather placid. As a result, in 1980 the lahar came quite close to smashing the only transportation corridor route for road and rail between Seattle and Portland. Crews scrambled to keep the log jams from piling up in the steaming and cementing river underneath the bridge. The flow did reach as far as dumping a significant amount of sediment in the Columbia river downstream from the vital freshwater maritime ports in Portland, severely impacting shipping operations on the West Coast for several months in 1980, and dredging operations have had to be escalated since then.

To protect the railroads and highways in the transportation corridor, the US Army Corps of Engineers constructed a massive sedimentation retardation system as seen near the bottom of this third picture. While it likely can't contain a 1980-class lahar, it can block or retard the debris flow to regulate the downstream flow and prevent massive flooding. Additionally, the concrete-like nature of the mudflows makes downstream flood control and cleanup much more difficult.

This picture was taken prior to the 2004 eruptions and development of the 2nd cone. The position and hieght of the new cone is marked in red, while the older cone is in blue. Scientists think that the reason for the locational difference is that as the mass of the old cone had relatively cooled and hardend, the pressure released in 2004 and yesterday is from the same magma vent under the old cone, but squirting to the south side due to the geological inclination to the north. As long as the passage remains hot, magma and gas pressure can continue to periodically vent in this side channel.

[mattxr 9]

i would say a big bang USA extinction will come from yellostones Super Volcano... The Biggest Active Volcano

Quote[/b] ]Not all super volcanoes have been found, but one of the largest is in Yellowstone Park, USA. Scientists searching for the caldera in the park could not see it because it was so huge - only when satellite images were taken did the scale of the caldera become apparent - the whole park, 85km by 45km, is one massive reservoir of magma. The idyll landscape of Yellowstone (below) could soon explode with devastating consequences.

When will it next erupt?

Scientist have discovered that the ground in Yellowstone if 74cm higher than in was in 1923 - indicating a massive swelling underneath the park. The reservoir is filling with magma at an alarming rate. The volcano erupts with a near-clockwork cycle of every 600,000 years. The last eruption was more than 640,000 years ago - we are overdue for annihilation.

Quote[/b] ]What would be the effect of an eruption?

Immediately before the eruption, there would be large earthquakes in the Yellowstone region. The ground would swell further with most of Yellowstone being uplifted. One earthquake would finally break the layer of rock that holds the magma in - and all the pressure the Earth can build up in 640,000 years would be unleashed in a cataclysmic event.

Magma would be flung 50 kilometres into the atmosphere. Within a thousand kilometres virtually all life would be killed by falling ash, lava flows and the sheer explosive force of the eruption. Volcanic ash would coat places as far away as Iowa and the Gulf of Mexico. One thousand cubic kilometres of lava would pour out of the volcano, enough to coat the whole of the USA with a layer 5 inches thick. The explosion would have a force 2,500 times that of Mount St. Helens. It would be the loudest noise heard by man for 75,000 years, the time of the last super volcano eruption. Within minutes of the eruption tens of thousands would be dead.

The long-term effects would be even more devastating. The thousands of cubic kilometres of ash that would shoot into the atmosphere could block out light from the sun, making global temperatures plummet. This is called a nuclear winter. As during the Sumatra eruption a large percentage of the world's plant life would be killed by the ash and drop in temperature. Also, virtually the entire of the grain harvest of the Great Plains would disappear in hours, as it would be coated in ash. Similar effects around the world would cause massive food shortages. If the temperatures plummet by the 21 degrees they did after the Sumatra eruption the Yellowstone super volcano eruption could truly be an extinction level event.

[walker 0]

Hi all

They doing a docu-drama on a Yelowstone eruption on BBC on this coming Sunday and Monday it should be worth a watch.

http://www.bbc.co.uk/sn/tvradio/programmes/supervolcano/index.shtml

It is based on the excelent documentry by the Hozizon science program a few years back

http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml

If it happens in our lifetime Al Qaida and Bin Laden will probably claim it as suicide bombing  

I hope it does not happen before I manage to climb the Nose on El Cap'.

Last year in April reports from yellowstone were of a so called swarm event

Quote[/b] ]In April 2004 there was an increase in earthquake activity, called a swarm

http://volcanoes.usgs.gov/yvo/activity.html

Last month

Quote[/b] ]During the month of February 2005, 61 earthquakes were

located in the Yellowstone region.  The largest of

these shocks was a magnitude 2.8 on February 22, 2005

at 6:49 PM MST, located about 9.1 miles north northwest

of Madison Junction, Wyoming. No earthquakes in this

period were reportedly felt.

Earthquake activity in the Yellowstone region is at

relatively low background levels

ibid

If you want see the US Government fact sheet on Yellowstone.

Quote[/b] ]In the 1970s, a resurvey of benchmarks discovered the unprecedented uplift of the Yellowstone Caldera of more than 28 inches (72 cm) over five decades.

http://pubs.usgs.gov/fs/fs100-03/ Makes for a nice scary bedtime read.

But it is this picture of the big target painted in range changes that gives me the willies:

http://pubs.usgs.gov/fs/fs100-03/images/insar.jpg

Quote[/b] ]A new satellite-based technique known as Interferometric Synthetic Aperture Radar (InSAR) allows direct and precise measurement of the vertical changes in ground level. This InSAR image of the area around the Yellowstone Caldera (dotted line) shows vertical changes during the 4-year period 1996–2000. The ringed pattern centered northwest of Yellowstone Lake is a prominent area of dome-shaped uplift. Each complete cycle of colors in the color bands represents a little more than one inch (28.3 mm) of vertical change. Yellow triangles are continuous GPS stations; white dots are locations of earthquakes in the period 1996–2000.

I reccommend everyone to have a look through the links they are very interesting and there is always a nice simple explanation on Wiki of what a so called supervolcano is suposed to be and where the other supervolcanos are in the world.

http://en.wikipedia.org/wiki/Supervolcano

Of course their position in 3 dimensional space is not near as important as the probable position of their next eruption in the fourth dimension is to us. Yellowstone is the only one that is due to erupt.

http://en.wikipedia.org/wiki/Yellowstone_Caldera

Hope you all have pleasant nightmares    

EDIT1 By the way checkout the neat online disaster Flash game you have to:

Quote[/b] ]Respond to a disaster

As the newly appointed chief of the Emergency Management Agency for Bluebear County, it's your job to handle an eruption of the fictional Mount Spur. Are you up to it?

http://www.bbc.co.uk/sn/tvradio/programmes/supervolcano/game.shtml

Kind Regards Walker

[LP4Life 0]

When it blows I plan on being there to take some pics

[shinRaiden 0]

Quote[/b] ]

I hope it does not happen before I manage to climb the Nose on El Cap'.

I believe you're referring there to Yosemite in California, nowhere close to Yellowstone, but geologically unstable just the same.

http://www.tatsumaki.net/sth/mt_roasty.jpg

This is a panorama of the mess called the 'Pacific' Northwest. Starting from the west, you have the Pacific plate diving under the NA plate off the coast. Incidently, researchers are rushing out atm to a newly erupting underwater seamount ~320km off the coast of Vancouver Island. The pressure buckle causes an immediate uplift mountain range - just out of picture on the left border - called the Olympic Mountains. Although not volcanic, the layers exposed reveal regular tsunamis and landshifts that would make the recent Sumatra tsunami look like pebbles in a bathtub.

Coming off the east slope of the stressed range, the plate fractures in the greater Puget Sound region. To get an idea of what the faults look like under Seattle, just consult a shattered car window for an excellent visualization. I hinted at that with the little red dots. It's so messed up nobody has a clue what might really happen. Underneath that all the edge of the Pacific plate starts breaking off.

Moving east to the orange line of the volcanicly active Cascades range, this is where all the crap that's fallen off the Pacific plate boils up into a stressline at the edge of the plate and pops in any number of hotspots. I've noted the active or semi-active major peaks in Washington and Oregon, Mt. Shasta and Lassen Peak in northern California are also culpable suspects.

Mt. Rainier, which has grown approximately 1~5m during the past 15 years I've lived in it's shadow, last had a significant eruption about 500 years ago, resulting in the mudflow outlined on it's north face. I live near the top end of where that mudflow exited the mountain canyon. The path marked to the left shows the presumed path of the next flow, which is a geologically "imminent threat"

Immediately to the south is Mt. Adams, which has a pleasently warm and active crater on it's summit, and to the SW marked in orange is Mt. Saint Helens with the previous mudflow marked as well.

The area to the east outlined in purple, is the greater Columbia River basin. The base is all volcanic of relatively similar vintage throughout. It is also home to some of the most significant orchard and wheat areas in the US, along with a about a dozen major dams that routinely keep California's lights on.

Surrounding that to the east are the Oregon-Idaho Blue Mountains intersecting with the southern Canadian Rockies. These ranges are an odd mix of non-volcanic material positioned and rearranged by volcanic and tectonic forces.

The long red arc shows the historical track of the Yellowstone Caldera's movements as the NA plate has shifted eastwards. That is the upper Snake River area, and is also a vital farming district.

Beginning in the lower right hand corner you have the US Rocky Mountains. Although commonly regarded as non-volcanic uplift mountains, recent research has discovered dangerous faultlines running along the western edge, that contributed to the sudden and extreme elevation of Utah's Wasatch Range.

-edit-

This one is Lassen Peak in northern California. The peak is the after-cone of a much larger mountain, the crater of which you can see outlined. ~8km in diameter.

This one is an oddball lots of people don't know about. It's in northern New Mexico, due south of Yellowstone. To the best of my knowledge it's long dormant, but the caldera is still 25~30km in diameter, about the same as the Yellowstone core.

-edit-

http://www.tatsumaki.net/sth/or.jpg

This one is another angle, showing the chain from the 10km in diameter Crater Lake north to Mr. Rainer, ~440km to the north.

[Placebo 29]

Walker please don't hotlink images over 100kb