Skip to comments.Signs Of An Eruption
Posted on 08/29/2003 5:37:16 PM PDT by blam
Signs of an eruption
For days before the eruption the volcano had been screaming 'I'm about to explode'
A scientist has found a way to use earthquakes to predict when volcanoes will erupt. Swiss scientist Bernard Chouet fell in love with volcanoes when he witnessed spectacular fountains of lava spewing from Sicily's Mount Etna in 1969.
Now at the US Geological Survey, Chouet has devoted his career to finding a way to predict deadly volcanic eruptions. He is haunted by a disaster in South America that killed 25,000 people.
When Colombia's Nevado del Ruiz volcano erupted in 1985, it melted a glacier capping the mountain. Water and volcanic ash combined to produce devastating mudflows that wiped the entire town of Armero off the map.
By then Chouet had developed a theory that volcanic eruptions should be preceded by a type of earthquake he called a long period event.
Chouet believed that long period events were a sign that pressure was building up inside a volcano.
When he finally saw the earthquake records from Nevado del Ruiz, a year on from the disaster, he was horrified.
Chouet saw long-period events all over charts. For days before the eruption the volcano had been screaming "I'm about to explode" but no one had heard the warning.
In the early 1990s another Colombian volcano, Galeras, became restless. Long period events had again appeared on the charts - a clear sign of an impending eruption, according to Chouet.
But US volcanologist Stanley Williams was sceptical about Chouet's approach. Apart from the long period events the volcano was completely quiet.
So on 14th January 1993 Williams led a group of scientists into the crater of Galeras to measure gas emissions.
It was a tragic misjudgement. As they were preparing to leave the crater the volcano erupted, killing six of his colleagues and three tourists. Williams himself was severely injured.
In December 2000 Chouet was vindicated in dramatic fashion. For several years the mighty Popocatépetl on the outskirts of Mexico City had been gently steaming.
Fumarole volcano But then the long period events started - so many that they merged into a continuous tremor that could be felt in nearby villages.
Using Chouet's methods scientists at the National Centre for Prevention of Disasters in Mexico City predicted that there would be a large eruption in two days. The government evacuated tens of thousands of people.
Forty eight hours later, bang on time, the volcano erupted spectacularly. It was Popocatépetl's largest eruption for a thousand years and yet no one was hurt.
Genetic detectives figure the human gene pool was very tiny 75000 thousand years ago. Something horrible nearly made mankind extinct. A supervolcano like the one at Yellowstone erupted at about that time period. Thanks to a handful of people, both private and government, that have special places set aside for nuclear war I don't think extinction will happen this time, but the next eruption event at Yellowstone is already due by noting it past history of eruptions. The last time it went off Kansas was covered by ash at least 10 feet thick.
The Toba 'super volcano' blew 75,000 years ago and only 2-5,000 humans worldwide survived. This 'bottleneck' is detectable in human DNA.
This is hugh
True. And women and minorities will be hurt the most.
We now have both. It will be a little tough for a year or two. But we'll be okay.
By the way, the last time Yellowstone blew, the ash only cover everything west of the Mississippi in the U.S. If your east of the Smokey Mountain, you'll probably be okay.
It will not be the end of the world, it will just be a very bad day for anyone caught in the blast.
That was TOBA (click the link and read, they say less than 1,000 humans survived.)
So...what are you gonna eat for the 2-4 years it will take for the dust veil to clear?
His analogy of a magma tube being like a plugged pipe in a pipe organ was spot on. These long period events are the mountain pressuring up to blow. A lot of his colleagues at Galeras bet their lives on Stanley Williams' theory that low gas emissions meant low eruption probability. Six of them lost.
I'd love to see his long period event model plugged into a supervolcano system, not that it would matter a hell of a lot if Yellowstone lets go. There won't be anyone left to say "I TOLD YOU SO!" to.
Toba > 700 Cubic Miles of stuff.
By the way, after this is over, the ash itself will actually enrich the soil that it cover, allowing for better farming in the future.
Err, well, if the entire Caldera went up, it would kill every human being in Wyoming, Idaho, and Montana, and end all agriculture in the midwest for years, likely leading to mass starvation in the US, which is more than a few bison :-)
However, it's extremely unlikely that happens in our lifetimes.
The recent spate of articles about the lake are about the possibility of a small localyzed eruption, NOT the caldera going up. It's possible to have small eruptions at Yellowstone without a full caldera blast.
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