Super Volcanoes

[C1ay]

The latest eruption of Mt. Etna in Sicily, which has destroyed a few buildings, shut down the airport and crept into a ski area, produces dramatic nighttime video of hot rolling lava and explosive fireworks. But compared to the known history of volcanoes and even its own past, Etna's 2001 pyrotechnic show is so far geologically pathetic.

 

Likewise, the eruption of Mt. St. Helens in 1980 was a volcanic sneeze compared to what scientists say America will experience one day. And a mysterious four-inch-high bulge in the ground of central Oregon is, so far, little more than a conversation piece.

 

Sooner or later, geologists warn, a "super volcano" will strike.

 

The eruption of pent-up energy will cover half the United States in ash, in some places up to 3 feet (1 meter) deep. Earth will be plunged into a perpetual winter that would last years. Some plant and animal species will disappear forever.

 

More...

 

Yellowstone is one of these super volcanoes. It erupted 2 million years ago, 1.2 million years ago and 600,000 years ago. This frequency indicates it could be due again at any time. Is there anything mankind should do to prepare for this inevitable, cataclysmic event?

[bumab]

Yellowstone is one of these super volcanoes. It erupted 2 million years ago, 1.2 million years ago and 600,000 years ago. This frequency indicates it could be due again at any time. Is there anything mankind should do to prepare for this inevitable, cataclysmic event?

 

My understanding of the forces behind such a big eruption was the amount of dissolved gasses in the magma chamber below Yellowstone. When the caldera collapses (hence the name), all those gases are no longer under pressure, thus violently turning to the gasseous phase in a planet sized attack of the bends.

 

I wonder if it would be possible to inject either chemicals to dissolve out the gasses peacefully (recombine them to more benevolent molocules), or just let off the pressure slowly (I doubt that's possible, but hey).

[Fishteacher73]

For a massive explosion you need to have the pressusres trapped and build up. Granted Yellowstone is enormously active (the site has more geothermal phenomenon than the rest of the world combined), this activity is just the thing to help keep these massive pressures from accumulating. This does not mean that Yellowstone is quiet, but at its current state, it is believed that a truly catastophic eruption is unlikely.

 

But all of this is somewhat relative. There are enormously powerful events in terms of human perception, but inconsequential on the massive scope of the "super volcano". I don't have the book with me currently, so the exact details may be a bit off, but a good example occured in the early 20th century. (I do not recall the exact date or placement in the park but here's a basic synopsis with the relative power shown). A minor tremor caused about a 1/4 of the side of a moutain to slide off. Luckly Yellowstone was not the huge tourist attraction it is today, but about 30 people died as it took out a campsite. The rubble continued up the other side of the valley to about 400 feet up the face of the opposite moutain.

 

The sheer unpredictablility of such events is amazing. For many active sites have a basic cycle of activity it is quite erratic. A volcano that has a patern of erupting evry 900 years or so may suddenly have a dormant period of 25,000 years...We truly do not understand these processes. (We know more about the interior of the sun than we know about the interior of the Earth).

[C1ay]

For a massive explosion you need to have the pressusres trapped and build up.

 

The resevoir of magma and gas beneath Yellowstone is now 31 miles long, 19 miles wide, and six miles deep. The pressure must be immense. It doesn't need pressure to erupt though, it is a drop in pressure that causes these volcanoes to erupt. Imagine the super heated water in the raditor of your car. Trapped pressure keeps it from boiling. Vent the cap and it explodes. Pressure venting from Yellowstone's resevoir will cause the same effect. At some critical point as the pressure falls the superheated water in the magma chamber will explode. This is the trigger that sets off super volcanoes.

[Fishteacher73]

A sudden drop may also trigger such events, as I said they are still poorly understood. According to the staff geologist at Yellowstone (As I said in my last post, my book is at home and some of thefinite detail I do not recall. So I do not recall his name) that the all the "small" geothermal activity currently is disapating pressure and energy and a "super volcano" is unliklely under the current circumstances.

[Turtle]

---Yeah, don't want to scare away any touristos now do we? In fact the geothermal activity is not venting all the pressure as one end of Yellowstone Lake has lifted so much that the water is flowing out the other end & killing stands of Aspen. Yes, it's taken years, but this rise is continuous & increasing in rate of growth.

___Yes maybe later, maybe now, but the original question of what can you do is germaine. You can get prepared for any natural disaster with water, food, medkit, fuel, clothing, etc. ' Common sense is not common', my friend Mark Clemens said. Prepare or suffer the consequences. :hihi:

[C1ay]

Yes maybe later, maybe now, but the original question of what can you do is germaine. You can get prepared for any natural disaster with water, food, medkit, fuel, clothing, etc. ' Common sense is not common', my friend Mark Clemens said. Prepare or suffer the consequences. :hihi:

 

But, can we narrow down the timing of the event with current technology? Can we probe it or do we risk accelerating the event? We know it is an inevitable event. Will it wipe out the world's supply of grain. There are 100's of questions to consider but, is there anything the world should do to prepare as a whole if for no other reason than to preserve the human race? We may have a 1000 years to prepare or it may happen tomorrow. I know there's nothing we can do to stop it or prevent it.

[Turtle]

___Many of the suggestions you give for preparing have validity; no one wants to pay for something so expensive on such low probability of needing it. Nonetheless, we are talking about it because people/scientists have brought it to our attention. Considerable new instrumentation is in place in Yellowstone because of the new activity.

___Now do you also know that Long Valley in California is Long Valley Caldera & also a SuperVolcanoe? The government made the town build an escape road out the back of the dead end valley; they call it a scenic route so as not to scare anyone. :hihi:

___

[nemo]

The government made the town build an escape road out the back of the dead end valley; they call it a scenic route so as not to scare anyone.

Kind of like making lemmings wear lifejackets, isn't it?

[C1ay]

Now do you also know that Long Valley in California is Long Valley Caldera & also a SuperVolcanoe?

 

Yeah, there's really quite a few of them. Crater Lake in Oregon is another in the U.S..

[Turtle]

___A Lemming afloat, is a Lemming with a chance. Chance favors the prepared Lemming mind. :( :(

[C1ay]

 

Geologists have called for a taskforce to be set up to consider emergency management in the event of a massive volcanic eruption, or super-eruption...

 

The recommendation comes in a report timed to coincide with a BBC TV drama that depicts a fictional super-eruption at Yellowstone Park in Wyoming, US.

 

A super-eruption is also five to 10 times more likely to happen than an asteroid impact, the report claims...

 

It would have a similar effect to a 1.5km-diameter space rock striking Earth, they claim.

 

But while impacts of this type are estimated to occur once every 400-500,000 years, the frequency of equivalent super-eruptions is about once every 100,000 years...

 

One past super-eruption struck at Toba in Sumatra 74,000 years ago and is thought by some to have driven the human race to the edge of extinction. Signs from DNA suggest human numbers could have dropped to about 10,000, probably as a result of the effects of climate change...

 

More at the BBC.....

 

Two things strike me statistically. Yellowstone has erupted approximately every 600,000 years and it has been 600,000 years since the last eruption. Super eruptions occur somewhere about every 100,000 years and it has been 74,000 years since the last eruption. Statistically it would seem an event at Yellowstone could be approaching. :)

[Buffy]

Two things strike me statistically. Yellowstone has erupted approximately every 600,000 years and it has been 600,000 years since the last eruption. ...Statistically it would seem an event at Yellowstone could be approaching.

Lies, Dam lies, and statistics. Yeah, those are the averages, but its no more likely to happen now than in 100,000 years just because the last one was "the average number of years ago." Statistics aren't very intuitive sometimes....

 

Stochastically,

Buffy

[Fishteacher73]

They have continually shown that statistical analysis of geologic events is basicaly useless. While there are average timeperiods between eruptions there are huge descrepencies that throw off the calculatuions...

 

If one were to average 5, 50, and 100 you would get about 52. If this were the various intervals between eruptions you would average an eruption aprox. every 52 years, but the data shows that this interval has only occured once. You had out lying data that skews the the average to give a number that is reasonably irrelevant.

[Turtle]

___For this very reason, ie. inapropriate use of stastistics, it is all the more important to monitor & study the super volcanoes. By this we at least have a potential for warning & consequently some time to prepare.

___Rather than a probablistic (statistical) model, I believe further study will reveal that a chaotic (fractal) model descibes many aspects of the geology of super volcanoes. :)

[Fishteacher73]

I think geologic activity runs in the same vein as climate. We can see predict short term activity usually, but all the factors are not as well understood as they are for weather patterns. One could viably even model geological activity with the same basic premises that are used in climate forecasting once all the contributing factors are discovered/understood, IMO. The same basic principles are being used (pressure, covection currents, etc.)

[Turtle]

Does IMO mean In My Opinion? Sorry for the newbiesk question.

___Regardless, I completely agree. We are after all ultimately talking about fluid dynamics. Moreover, since the recursive equations of chaos theory well model weather as in clouds & geology as in the surface terrain, it stands to reason the same is true of say magma chambers.

___The standard graphic of the magma chamber is this sort of generalized obloid form, & this may stem from lack of resolution in the data used to establish the boundries of a chamber. Since the surface boundry exhibits a fractal nature, it stands to reason the boundry of the magma chamber does as well.

___Until the inner boundry of magma chambers is better understood, the resultant effects cannot reliably derive. :cup: