Yellowstone Volcano Observatory scientists answer questions about Supervolcanoes

USGS Yellowstone Volcano Observatory ^ | March 2005

[Strategerist]

The director of the YVO has recommended watching it so it can't be that terrible; on the Discovery Channel tonight at 8PM and 11PM EST.

[canalabamian]

Thanks for posting the times. Kiddos will enjoy it...and have bad dreams about volcanoes destroying the world. ;)

[cripplecreek]

Cool I love this stuff.

[Sundog]

Remember your Science Project?

[Sundog]

1/730,000 for any particular year?

The probability goes way up when it has been 760,000 years since the last one.

Who knows that math?

[Strategerist]

The probability goes way up when it has been 760,000 years since the last one.

It's been 640,000 years since the last one.

There have only been three supervolcanic eruptions at the present location of the Caldera; that's what's known as a dataset that's far too small.

In any event, the time between the eruptions is longer than the time since the last one, so Yellowstone certainly isn't "overdue" in any sense you look at it.

And it may never have another supervolcanic eruption. Hotspots tend to gradually go dead over time.

[muffaletaman]

Yellowstone's volcanism is only the most recent in a 17 million-year history of volcanic activity that has occurred progressively from southwestern Idaho to Yellowstone National Park.

http://volcanoes.usgs.gov/yvo/figures/fig1.html

At least six other large volcanic centers along this path generated caldera-forming eruptions; the calderas are no longer visible because they are buried beneath younger basaltic lava flows and sediments that blanket the Snake River Plain.

The Huckleberry eruption - 2.1M years ago - 530 cubic miles

Mesa Falls - 1.3M years ago (800,000yrs) - 60 cubic miles

Lava Creek - 640K years ago (660,000yrs) - 216 cubic miles

From the site above, there are seven different "hot spots" areas, and each probably had 2 or 3 eruptions over the last 17 million years. The hot spots trend northeast, over a trail about 350 miles long.

There is no sign they have ended.

[Polybius]

Cool I love this stuff.

Well, I'm too close.

I'd rather have something that eats Michigan instead. ;-)

[stevem]

Do we have a clue how many calderas there are in the world? This article cited Yellowstone and Sumatra. I believe the Bay of Naples in Italy is one. How many are there?

[blam]

I'm watching.

[P.O.E.]

So far, some well-done graphics, and the expected cliche characters. Looks worth watching.

[cripplecreek]

Don't worry, It would kill most of us in this country anyway. Michigans downwind.

[cripplecreek]

Nature has all kinds of nasty little suprises. Check out this link about lake Nyos in Africa. It will make you wonder about what lies at the bottom of our volcanic lakes in America.

http://www.geology.sdsu.edu/how_volcanoes_work/Nyos.html

[blam]

"Do we have a clue how many calderas there are in the world? This article cited Yellowstone and Sumatra. I believe the Bay of Naples in Italy is one. How many are there?"

I read somewhere the other day that most known supervolcano locations are in the United States.

[blam]

Here's a list of the supervolcanos.

[blam]

"Nature has all kinds of nasty little suprises. Check out this link about lake Nyos in Africa. It will make you wonder about what lies at the bottom of our volcanic lakes in America."

The Fremch have installed 'exhaust pipes' all the way to the bottom of these lakes and are now slowly exhausting off any accumulated gasses.

[cripplecreek]

I was checking the system out that pumps water from the bottom of the lake. I remember reading about the lake Nyos disaster when I was a teenager.

[Jim Noble]

The probability goes way up when it has been 760,000 years since the last one. Who knows that math?

I do, and you're wrong.

If you flip a coin 1000 times and it comes up heads every time, the probability of heads on the 1001st flip is 0.5.

[AaronInCarolina]

I do, and you're wrong.

If you flip a coin 1000 times and it comes up heads every time, the probability of heads on the 1001st flip is 0.5.

Jim, you are correct, theoretically. In an unchanging system for which a probability has been established (such as a coin that has not been weighted to favor one outcome versus the other) probability on any given event is always the same without regard to previous outcomes. However, in the scenario which you cited where a coin flip yielded heads every time for 1000 times, it is highly likely that the coin is not a "legal" coin (one which has a 1-in-2 chance of heads), and therefore the 1001st flip will highly likely yield another head. However, I know you were talking hypothetically about 1000 heads in a row with a legitimate coin (as unlikely as it is), and you are therefore quite correct about the 1001st flip chance of heads being 50% chance.

That being said, applying this analogy to a volcano, which presumably is an ever-changing system, in my opinion is incorrect. The article pointed out that the 1-in-740000 chance was a quite crude approximation based only upon the lapse of time since the last eruption. It is probably incorrect to apply such rigid standards (as one does to a legitimate coin) to a crude probability concerning a volcano. A volcano eruption is typically cyclic, and is therefore a constantly changing system whereby passage of time almost certainly increases the real probability of eruption, crude estimates not withstanding.

[Strategerist]

Glancing at the list it seems pretty flawed; Crater Lake's cataclysmic eruption was a VEI 7, not 8...I've never seen it classified as a supervolcano. The Australian volcano is very old and really can't be considered as potentially active. Some of the others listed were not VEI=8 eruptions either.