Mount St. Helens could erupt within 24 hours

[GioFX]

Da Cnn.com:

USGS: Mount St. Helens could erupt within 24 hours

Observatory 3 miles from volcano's base evacuated

Saturday, October 2, 2004 Posted: 6:58 PM EDT (2258 GMT)

VANCOUVER, Washington (CNN) -- Scientists warn that Mount St. Helens could erupt within 24 hours, and with more force than previously expected.

Saturday afternoon, the U.S. Geological Survey issued a Level 3 Volcano Alert, indicating an eruption could occur in the next 24 hours, said Tom Pierson with the USGS. That level alert is the third of four -- with the fourth being eruption.

"There is a 50 percent chance or greater that there is going to be an eruption and a good chance that it will involve magma," Pierson said. "We're watching it very closely."

An observatory three miles from the base of the mountain was evacuated Saturday. Bumper-to-bumper traffic snaked down the road from the observatory after the order.

Scientists have been closely watching Mount St. Helens since a small eruption spewed a harmless plume of steam and ash thousands of feet into the air Friday. It was the end of a week in which the number of earthquakes near the volcano grew significantly.

One scientist described the eruption, the biggest in 18 years, as a "hiccup."

Seismic activity decreased shortly after the noon (3 p.m. ET) eruption, but picked up again within hours. Peter Frenzen, a scientist with the Mount St. Helens National Volcanic Monument, said a 2.0 magnitude earthquake was detected.

A small explosion was detected on the south side of the volcano's lava dome, where cracks had been detected in a glacier, said John Major of the U.S. Geological Survey.

Scientists said the presence of magma could indicate the potential for a more serious eruption.

Molten rock is called magma before reaching the surface, where it is called lava.

Scientists had been predicting a minor eruption after swarms of small earthquakes were detected, and the mountain's volcanic dome shifted three inches since Monday.

In anticipation of an eruption, the mountain was closed to hikers, and the media and sightseers gathered at a visitors center 5 miles away.

Friday's eruption was a mere sideshow in comparison to the cataclysmic eruption May 18, 1980, which blew off more than 1,000 feet from the top of the mountain. That eruption killed 57 people, left deep piles of ash hundreds of miles away and caused $3 billion in damage.

After that disaster, small eruptions continued at Mount St. Helens until 1986, when the volcano finally went quiet. Major said Friday's eruption was comparable to the minor eruptions seen during that period.

Mount St. Helens is about 50 miles northeast of Portland, Oregon.

[GioFX]

Da Nytimes.com:

Bigger Eruption Predicted at Mount St. Helens

By SARAH KERSHAW

Published: October 3, 2004

CASTLE ROCK, Wash., Oct. 2 - Scientists monitoring Mount St. Helens, which erupted Friday for the first time in 18 years with a minor explosion, said on Saturday that they were expecting a more powerful eruption within a day or so.

The government raised the advisory for volcanic activity to Level 3, the equivalent of a "code red" and the highest stage in a system used to indicate the likelihood of a volcanic eruption that could endanger life or property.

The government scientists had earlier said they expected to see more small to moderate explosions after a series of earthquakes culminated in a plume of steam and ash on Friday, rising 10,000 feet into the air but posing no threat to health or safety.

But on Saturday, the earthquakes intensified, and shortly after noon, the volcano emitted a brief burst of steam, which was followed by a continuous, low-frequency tremor that lasted 50 minutes, believed to be caused by the movement of magma, or molten rock, underground.

That suddenly created a more serious situation at Mount St. Helens, the most active volcano in the lower 48 states. But scientists said they did not expect an eruption on the magnitude of the May 1980 explosion that killed 57 people and caused widespread destruction.

Officials on Saturday evacuated an observatory five miles from the crater and warned that people with respiratory diseases could be affected if large amounts of ash became airborne.

Hundreds of excited tourists who had flocked to Mount St. Helens in recent days were forced to move to a lookout point several miles below the observatory, causing a deep traffic jam on the one winding road that leads from this small town in southwestern Washington up to the mountain.

The 2,100 residents of this town and others near the mountain, however, were not evacuated. Officials, including Interior Secretary Gale A. Norton, who held a news conference Saturday afternoon in nearby Vancouver, Wash., said their houses were far enough away - 30 miles to the west - to be safe.

"This is red alert," Ms. Norton said, adding, "Overall, we are very fortunate that no one lives directly in the area that would be most impacted."

C. Daniel Miller, a scientist at the United States Geological Survey, said he expected an eruption "larger than what we saw on Friday, probably by quite a bit."

The 50-minute tremor "is the kind of seismic signal that occurs not when rock is breaking, but when magma is actually moving up in the throat of the volcano," Dr. Miller said at a news conference Saturday evening.

"That's the sort of thing that frankly sends a chill up the back of a volcanologist," he said.

Scientists said yesterday that they saw more signs of deformation at the south side of the lava dome, a half-mile wide, 925-foot high bulge at the center of the volcano's crater that was created by eruptions between 1980 and 1986.

The crew aboard a helicopter taking measurements Saturday reported the smell of rotten eggs, probably hydrogen sulfide emanating from magma. Until then, scientists had not detected significant amounts of volcanic gases. Gas-rich magma is more likely to erupt explosively.

The greatest danger was expected to be potentially large ash plumes, which could shoot tens of thousands of feet up. The ash could be accompanied by lava flow and possibly blow much farther northwest, depending on the weather, and cause health problems for anyone with asthma or other respiratory diseases, said Dr. Thomas Pierson, a geologist with the geological survey.

And if the mountain glacier melted as a result of an eruption, it could create a "debris flow" cascading down the mountain, officials said.

The earthquakes recorded over the past week, subsiding briefly after the Friday explosion, were the most intense seismic activity on the mountain since before the massive May 1980 eruption.

Before Friday, the mountain had been dormant for 18 years. Scientists said they had initially expected any eruption to be fairly minor, but were now saying it could be more serious.

Castle Rock residents, many of whom witnessed the 1980 explosion, which dumped truckloads of ash on this town, seemed to be taking the new development in stride and expressed little worry on Saturday, saying nothing could compare to the 1980 event.

"I know it might sound like the strangest thing in the world," said Laura Dodd, the owner of Lady Bug Antiques in downtown Castle Rock, who observed scores of tourists passing through town Saturday on their way to or from the mountain. "But the locals are not taking it very seriously. "We're just watching," she said. "It's exciting, but we're not really frightened or anxious."

Bobbie Stout, the cashier at North Fork Survivors, a novelty shop on Route 504 about 25 miles west of the mountain, said she had seen cars "rushing up the mountain" before they were evacuated Saturday afternoon, and that there was an excitement in the air.

"I lived through the first one," Ms. Stout said, adding that she was slightly concerned about the glacier melting but otherwise calm. "I'm not all that nervous."

[gunno]

[GioFX]

Originariamente inviato da gunno

[LittleLux]

Originariamente inviato da gunno

Che vui dire? Su, non fare il timido

[kaioh]

GioFx...va a quel paese !! Perché ti ostini a mettere articoli in inglese?non sai leggere l'italiano?
mi fai scervellare per leggerli .

[*sasha ITALIA*]

si almeno un riassunto in ita...ma il monte St Helens è quello che esplose negli anni '80 vero?!

Ci sono foto dell'eruzione??!

[LittleLux]

Originariamente inviato da *sasha ITALIA*
si almeno un riassunto in ita...ma il monte St Helens è quello che esplose negli anni '80 vero?!

Ci sono foto dell'eruzione??!

Si, proprio lui. All'interno del cratere formatosi a seguito della prima eruzione esplosiva, negli anni si è formato un nuovo cono vulcanico, cresciuto ad un ritmo notevole, segno evidente della notevole attività e pericolosità della montagna.

P.S.: QUI puoi trovare informazioni in italiano.

[kaioh]

conoscete il super vulcano sotto il parco di yelowstone?

[*sasha ITALIA*]

[LittleLux]

Originariamente inviato da kaioh
conoscete il super vulcano sotto il parco di yelowstone?

Si, è una enorme caldera risalente a qualche miliaio di anni fa. I gaiser ed i fenomeni termali che si possono osservare al giorno d'oggi stanno ad indicare l'attività che ancora contraddistingue quell'antico vulcano.

[kaioh]

Originariamente inviato da LittleLux
Si, è una enorme caldera risalente a qualche miliaio di anni fa. I gaiser ed i fenomeni termali che si possono osservare al giorno d'oggi stanno ad indicare l'attività che ancora contraddistingue quell'antico vulcano.

risulta che non è solo un residuo, è in fase crescente visto che il terreno si sta alzando in vari punti , di poco ogni anno ma si alza.

[LittleLux]

Originariamente inviato da kaioh
risulta che non è solo un residuo, è in fase crescente visto che il terreno si sta alzando in vari punti , di poco ogni anno ma si alza.

Infatti, e alcuni preconizzano una eruzione che potrebbe essere devastante...ma credo esagerino, almeno nel breve periodo.

[GioFX]

ma che c'è da capire? usate internet e non sapete una parola di inglese?

[osky10]

l'eruzione del 1980 fu devastante anche xkè sciolse tutto il ghiaccio e la neve che ricopriva la cima, ora è completamente brullo.

[majin mixxi]

Originariamente inviato da GioFX
ma che c'è da capire? usate internet e non sapete una parola di inglese?

ma almeno tu lo sai?

[GioFX]

Originariamente inviato da majin mixxi
ma almeno tu lo sai?

direi di si, o mi credi così idiota da postare articoli alla cazzo?

[LittleLux]

Originariamente inviato da GioFX
direi di si, o mi credi così idiota da postare articoli alla cazzo?

[majin mixxi]

Originariamente inviato da GioFX
direi di si, o mi credi così idiota da postare articoli alla cazzo?

[GioFX]

Originariamente inviato da majin mixxi
è quello che penso!