Shaky faultline raises the threat of a super-volcano (Sumatra)

Shaky faultline raises the threat of a super-volcano

April 01, 2005
The Australian

AS if earthquake-ravaged Indonesia doesn't have enough to worry about, now scientists warn that a Sumatran super-volcano might blow its top at any time. If it does, the blast will toss hundreds of thousands of cubic kilometres of rock and ash into the atmosphere, dwarfing the eruptions of Krakatoa, Mount St Helens, Pinatubo and any conventional volcanic explosion of the past tens of thousands of years.

"These super-volcanoes are potentially the greatest hazard on Earth, the only greater threat being an asteroid impact from space," said Ray Cas, a vulcanologist with Monash University in Melbourne.

Professor Cas said a "major tectonic event" could be enough to trigger a deadly super-volcanic eruption. The likelihood that the Toba – the largest super-volcano on Earth – will erupt has increased significantly due to geological stresses generated by the recent quakes.

Worse, Toba sits directly atop the faultline running down the spine of Sumatra. That is where seismologists say a third quake might strike.

http://www.theaustralian.news.com.au/common/story_page/0,5744,12717924%5E30417,00.html


Comparison of volumes produced by some of the greatest volcanic eruptions. The Young Toba Tuff has an estimated volume of 2,800 cubic kilometers (km) and was erupted about 74,000 years ago. The Huckleberry Ridge Tuff, erupted at Yellowstone 2.2 million years ago, has a volume of 2,500 cubic km. The Lava Creek Tuff, erupted at Yellowstone 600,000 years ago, has a volume of 1,000 cubic km. The May 1980 eruption of Mount St. Helens produced 1 cubic km of ash. Not shown is the Fish Canyon Tuff of the San Juan Mountains of Colorado. The Fish Canyon Tuff was erupted 27.8 million years ago and has an estimated volume of 3,000 cubic km.



http://volcano.und.nodak.edu/vwdocs/volc_images/southeast_asia/indonesia/toba.html

Landsat image of Toba caldera:

and disaster, maybe we are living in the end- times. Anybody else think about the Mayan calendar and how it stopped at 2012? I keep thinking I should become a buddhist nun or something and spend the rest of my days zenning out!

Yep, it stops just two shopping days before Xmas in 2012.

I wouldn't worry too much about it, though. Our own calendar stops on December 31st. Every year.

--p!

is kind of a bummer.

Most people don't realize that the Mayan Long Count is just a counting system. No significance was given to the starting or ending dates. 12/23/2012 in the LC will be like your odometer hitting 999,999.9 and then flipping over to 000,000.0

--p!

:hi: :party: Just in case.

New top ten disaster scenario!!!!!!

Right in there with Yellowstone erupting, the Gulf Stream shutting down resulting in a new ice age, basalt flows reactivating, a megathrust event followed by a Pacific-basin-wide tsunami, and Antarctica breaking in half and two giant ice floes roaming the ocean smashing into things!

Thanks for posting this!

We're gonna die!!!!!!!!!!!!!! :nuke:

and bird flu are manmade, or at least human influenced.

I'm ranking the top geological catastrophes, but including global warming scenarios, because the climate is dynamic.

But we could come up with a top ten manmade catastrophes, with nuclear warfare and the collapse of the dollar somewhere on the list.

We'll only have 17 years to survive in the punk-rocker-and-goth-infested lawless, gritty future before the Big Rock smashes into the Earth, setting the entire globe ablaze in a shower of flaming gravel.

Just in case, I'm laying in an extra supply of fuel for my jet pack.

--p!

n/t

the FICA tax stops being able to fund the billionaire tax cuts at the same time. Then the BIG ASS ROCK hits, killing lots of boomers. SS goes back in the black and the billionaires all get to keep their stupid tax cuts. What a rock of shit that is. I knew bush was behind it. The BASTARDS!

it's not going to "break in half" and result in "two giant ice floes roaming the ocean smashing into things"...

it's not even in the realm of possibility.

and I learned this in climatology at college, it's a solid land mass covered in a very thick sheet of ice. The fear is global warming will cause the ice mass to break in half (or other VERY large chunks) and slide into the ocean.

So I should have said "the Antarctic ice sheet breaking in half" etc etc.

the ice shelves that sit over water can and do and have been breaking off...but the ones on land may melt, but they aren't going to slide off the continent like an ice cube off a table- before that happened, it'd fracture into lots of pieces. if it did break in two and start moving to the sea, it would be more of a glacial pace.

I think I'll just stay home and read a book.

Two things come to mind here.

One thing is that these events are extremely rare; they happen on a tens or hundreds of thousands of year time frame. It would be very unlikely that this sort of thing will happen in our lifetimes. If they happen in a completely random sort of way, and happen every 50,000 years (say), the odds of it happening this century are 1 in 500.

But the other thing that comes to mind is that since this sort of event has never happened in recorded history, we simply have no idea what the warning signs or precursers -- if any -- would be. Even a relatively mundane eruption such as Mt. St. Helens in 1980 caught the geologists by surprise: almost all of the 57 people who perished in that eruption were outside of the zones declared to be hazardous. So I'm not sure if we would know it was about to happen if it were imminent.

A popular conspiracy theory these days seems to be that the Yellowstone supervolcano is fixing to erupt, and that the authorities are covering this up. There's said to be a huge bulge under Yellowstone Lake, certain geyser fields have been closed to tourists because the ground is too hot to walk on, trees are dying from volcanic gas emissions, etc. There's a lurid web site or two devoted to this. I'm a bit skeptical, but if anyone has better information about this, I would be interested to hear more.

...and don't worry about tomorrow, hey.

The Grassroots were Prophets.


I'm not being sarcastic.

Love it, brings back a lot of good memories!

...they specifically mentioned that the song was written from the perspective of a young man that had been recently drafted to go to Nam. Very poignant.

Yes, the underlying magma has become more active, and the chances are greater that it will erupt. The lake in the center of the caldera has been lifted over a meter and several spots nearby periodically become extremely hot. Then, there are the geysers. Let's not forget the dramatic increase in earthquake activity since 1995. That's all volcanic activity.

On the other hand, the changes are microscopic in comparison to what would happen right before a blow-out. I suspect we would get at least a month's lead time before it erupts. There would be tens of thousands of earthquakes and a series of near-blow-outs or small eruption before The Big One.

It's posssible that Yellowstone is going to erupt soon, and that the Rockefellers, Halliburton, and the Queen are keeping mum about it. But I doubt it. The earthquakes alone can be traced from anywhere in the world.

--p!

like Yellowstone's once every 6-700,000 years.... but it's been almost 660,000 years since the last eruption.

If Yellowstone erupted, the US would be about done for, and the rest of the world would be having some serious issues. Yellowstone is on a hot spot, much like Hawaii, but unlike Hawaii, instead of a gentle eruption, Yellowstone's eruptions could be very violent. The last major eruption was about 2,500 times the size of the mount saint helens eruption, so we're looking at thousands of cubic miles of material blasted into the atmosphere.

We're talking half of the US covered in over a foot of ash, killing all the plants, and we're talking major, major, major climate changes worldwide.

We'd be completely hosed.

of those who are not in the vicinity of the blast and the resulting pyroclastic flow

being blocked out, resulting in years of decreased sunlight, giving us something akin to nuclear winter.

We'd be completely hosed.

that, since such an eruption hasn't occured in recorded history, we may not know what to look for in order to anticipate it. Because of that, I don't believe there's a cover-up, because the authorities won't know, either.

Since eruptions cannot be prevented, and supervolcanos are both rare and catastrophic on a scale we've never seen, authorities are probably just playing the odds.

Just no coverage. Don't want to panic the Sheeple.

Actually, the Discovery Channel had a piece about Supervolcanos a few years ago. They talked about the Yellowstone volcano, and the lake rising (because of the bulge growing). The trees were dying because the lake was rising and they were being drowned.

Video rental places might have it.

If you want to freak yourself out... go here.

http://www.cuttingedge.org/news/n1852.cfm
and
http://www.earthmountainview.com/yellowstone/yellowstone.htm
and
http://armageddononline.tripod.com/volcano.htm

for science, go here

http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml
and
http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml
and
http://www.greaterthings.com/News/Earth_Changes/YellowstoneVolcano/

enjoy!

One thing is that these events are extremely rare; they happen on a tens or hundreds of thousands of year time frame. It would be very unlikely that this sort of thing will happen in our lifetimes. If they happen in a completely random sort of way, and happen every 50,000 years (say), the odds of it happening this century are 1 in 500.

According to the scientists watching Yellowstone very closely, we are overdue for an eruption in that area. One of the three Yellowstone calderas apparently has a history of erupting every 600,000-650,000 years, and we're about 40,000 years overdue for the next one. Is an eruption imminent? No, according to the same scientists, an eruption is not imminent. But, the last eruption to produce lava flows in the Yellowstone area took place about 70,000 years ago.

Two very good websites follow:

Yellowstone National Park.com
<http://www.yellowstonenationalpark.com/calderas.htm>

Super Volcano In Yellowstone National Park
<http://www.solcomhouse.com/yellowstone.htm>
===========================
But the other thing that comes to mind is that since this sort of event has never happened in recorded history, we simply have no idea what the warning signs or precursers -- if any -- would be. Even a relatively mundane eruption such as Mt. St. Helens in 1980 caught the geologists by surprise: almost all of the 57 people who perished in that eruption were outside of the zones declared to be hazardous. So I'm not sure if we would know it was about to happen if it were imminent.

No, the eruption at Mt. St. Helens didn't catch scientists by surprise. I was living on the west coast at the time, and the daily news was filled with talk about a possible imminent eruption. People living in and around Mt. St. Helens were told repeatedly to leave the area...most of the people who died failed to heed the warnings. A few of the dead were actually working for scientific groups monitoring the volcanoe. Meanwhile, 20,000 people had been evacuated from the immediate area prior to the eruption...and that probably saved their lives.

And yes, scientists have gotten much better at predicting eruptions:

Can We Predict Eruptions?
<http://www.pbs.org/wgbh/nova/vesuvius/predict.html>
===============================

A popular conspiracy theory these days seems to be that the Yellowstone supervolcano is fixing to erupt, and that the authorities are covering this up. There's said to be a huge bulge under Yellowstone Lake, certain geyser fields have been closed to tourists because the ground is too hot to walk on, trees are dying from volcanic gas emissions, etc. There's a lurid web site or two devoted to this. I'm a bit skeptical, but if anyone has better information about this, I would be interested to hear more.

Now why did you use the phrase "conspiracy theory"? Are you trying to ridicule the scientists studying Yellowstone? There's no conspiracy theory involved in the study of Yellowstone's calderas and their potential for erupting at some point in time.

As to your comments about "a huge bulge under Yellowstone Lake, certain geyser fields have been closed to tourists because the ground is too hot to walk on", please refer to the following website:

Yellowstone Lake
<http://en.wikipedia.org/wiki/Yellowstone_Lake>

QUOTE:

"In recent years (as of 2004), the ground under the lake has started to rise significantly, indicating increased geological activity, and parts of the national park have been closed to the public.

There is a 'bulge' about 2000 feet long and 100 feet high under a section of Yellowstone Lake, where there are a variety of faults, hot springs and small craters. Seismic imaging has recently shown that sediment layers are tilted, but how old this feature is has not yet been established."

....snip....

"In the 1990s, geological research has determined that the two volcanic vents, now known as "resurgent domes", are rising again. From year to year, they either rise or fall, with an average net uplift of about one inch per year. During the period between 1923 and 1985, the Sour Creek Dome was rising. In the years since 1986, it has either declined or remained the same. The resurgence of the Sour Creek dome, just north of Fishing Bridge is causing Yellowstone Lake to "tilt" southward. Larger sandy beaches can now be found on the north shore of the lake, and flooded areas can be found in the southern arms."

For more information in regards to the seismicity of Yellowstone, please refer to the following site:

Yellowstone National Park Region Seismicity Maps
<http://www.seis.utah.edu/HTML/YPSeismicityMaps.html>

==================================

I was in Portland at the time (I was a student at Reed College). It was very clear that a large eruption was imminent; the minor activity that began in March was described as "throat-clearing". But the size of the landslide and eruption was much bigger than anticipated: most of the fatalities were from people who were in zones deemed safe by the geologists. Basically, a 15-mile radius towards the north of the volcano was completely destroyed; the red zone was only 3-7 miles from the volcano.

When I used the phrase "conspiracy theory" I wasn't referring to the scientists. I am well aware of what the scientists say about Yellowstone: it is geologically active and someday there will be another supervolcano eruption there, but these events happen on a hundreds-of-thousands of years scale. Eruptions of this kind do not happen like clockwork every 600,000 years. We might be 40,000 years over due, but this means it might be more likely to happen in the next 10,000 years, but it doesn't necessarily mean in our lifetimes. The conspiracy-theory types I was referring to are those people who claim the eruption is imminent and that the government is not being forthcoming about the danger. The scientists are saying there is no reason to believe that a supervolcano eruption is imminent (that is, on a decades-long time scale). Some of the conspiracy theorists seem to be survivalists; there's an unsavory whiff of far-right politics on certain sites.

For current information about Yellowstone, please go to http://volcanoes.usgs.gov/yvo/. I've noticed that some of the Yellowstone information on the web (amateur websites) are a bit out of date; geyser fields have been closed and re-opened. (See http://www.nps.gov/yell/press/0453.htm.)

Oddly enough, one of the cable channels is preparing to do a story on the Yellowstone volcano. I can't remember if it's The Learning Channel or Discovery, but one of the ones that does the occassional science program. If memory serves (and please understand that it might not because I'm trapped at home with a 2 year old with stomach flu) it's due to air on the 10th or so of April.

While I'm not entirely convinced that Yellowstone is going to blow soon, it is an old volcanic area which has erupted massively in the past and there have been some things observed, like the dead trees, the bulge under Yellowstone Lake and an increase in geothermal activity in certain geyser fields that indicate it is not as geologically inert as the Park Service might hope.

Toba was one of the most influential factors in human evolution, and is the sole reason why the Earth doesn't have more subspecies of humans. The last time this thing went off, about 75,000 years ago, it only left a few thousand humans alive on the entire planet, a fact that can still be seen in our DNA today and which explains why humans look so much alike.

If it goes off again with anywhere near the force of the last one, you can write modern civilization off. There's more of us today so more will likely survive, but the resulting nuclear winter will probably pare us down to just a few million people...population levels not seen since before the last Ice Age.

but that is probably the best analogy, at best, we won't see the Sun for about 6-9 months at the earliest, and possibly years afterwards.

The actual effects are predictable and describable.

The America's, from San Francisco to Santiago Chile, will be buried in ash...several feet on the west coast, probably a foot on the east. Europe, the Middle east, and Africa will see many inches as well.

Once that settles out, the entire planet will be covered by a layer of thick, dark haze...think LA on a bad day in the 70's, only extending upwards high enough so that the sun is nothing more than a vaguely brighter portion of the sky.

For the people on the equator lucky enough to escape burial, the temps will rapidly drop to freezing. For those further north or south, the temps will get even lower. Plants will die. The animals that depend on them for food will die. Crops will fail around the globe. The entire world will grind to a dim, cold halt.

Gradually, over several months, the sun will grow brighter in the sky. Temps will start climbing above freezing again, first in the Equator, then further north and south. Once the air temperature is back above freezing, rain showers will clear the rest of the dust relatively quickly.

But the world will be dead for a while yet. The trees, the forests, and most of the animals will be dead. Slowly the seeds will sprout, new trees will grow, and the plants will come back, but it will take centuries for the world to become "normal" again. And the animals? Whatever animals survive will become the new dominant species, and their descendants will spread across the planet.

Will we survive? One current theory says that we're only here because our ancestors scavenged the frozen bodies of the animals that had died from the cold. There's no reason to think that at least some of us couldn't do it again, but there's no way that even 10% of our 7+ billion population could survive something like that. We don't have the food reserves, there aren't enough animals to eat, and quite frankly most of us are too out of touch with nature to survive something like this.

OMG..... :crazy:

These authors are trying to suggest that a quake on the fault will set off another supereruption from volcano...thereby demonstrating their ignorance about how supervolcanoes actually work.

Could an earthquake make Toba erupt again? Sure, but it wouldn't be a supervolcano eruption, just a regular one.

See, here's how supervolcanoes work: Lava (magma) builds up in a massive chamber underground without any eruptions. The chamber gets larger and larger, fuller and fuller, until it becomes so incredibly huge that is actually undermines the ground on top of it. In the case of Toba this lake of lava was something like 50 miles long and 15 miles wide when the plains, hills, and mountains above it simply gave way and fell into this gigantic magma filled sinkhole. The result of 750 square miles of Indonesian countryside collapsing into this sinkhole was the largest volcanic eruption in two million years.

The good news is that the magma chamber under Lake Toba isn't nearly as large OR as unstable as the one that detonated 75000 years ago, and the odds of it collapsing into a supereruption are almost nil. There isn't enough magma, there isn't enough rock, and the ground isn't weak enough. An earthquake MIGHT set off an eruption, but it will be more Pinatubo like.

Now Yellowstone is a different story...THERE'S a magma chamber just waiting to collapse. But at least it's not big enough to take out all of humanity (just North America and Europe).

...eruption. That event would almost assuredly threaten humans with extinction.

Yellowstone was much smaller than Toba, and wouldn't cause the global damage that Toba did. It's detonation would be horrific for the northern hemisphere, but those down south would be relatively unscathed (perhaps a slight reduction of sunlight...nothing too dramatic). It would cause a huge population reduction, but there'd still be billions of us left so extinction isn't really a concern.

We do NOT want that dome to collapse.

might not be seismic or other natural disaster, may not be world war, may not be an asteroid hitting, but something rather dramatic, affecting for the most part all the people of the planet is scheduled for August 13, 2010:

Aug. 13, 2010
http://www.gaiamind.org/aug13-2010.html

The accompanying copy:
This is probably the most difficult configuration of our time. Not since the Great Depression of the 1930's have Saturn, Uranus and Pluto been configured in such a challenging array. It will almost certainly coincide with a global crisis of previously unimagined proportions, most likely involving ecological upheaval bringing about economic collapse. However, the most skillful way to regard such an eventuality may be to see it as a necessary and inevitable consequence of our current trajectory, and quite possibly as the opportunity for a collective, global psycho-spiritual death-rebirth process, which we as a species must undergo in order that we might fulfill all of the prophesies in a way nobody could have foreseen, and be reborn as one. May we all prepare ourselves to act as midwives to that process. It will take great clarity to hold focus when all about us are in despair.

----------------
Plenty of people will dismiss this. How 'bout we meet up in the weeks afterwards and discuss it all again?

suggested potential solutions: channelling rivers and lakes into nuclear crevasse; using non-radioactive nuclear blasts to eliminate pressure little by little--only killing a few million people each time; getting Terri Schiavo's parents to hold a vigil, etc.

But, seriously, have any of these been proposed?

Channeling water into the magma chamber would simply cause a steam explosion and set it off early. Eliminating pressure really isn't technologically feasible.

The formation of supervolcanoes are a natural part of the planet, and we can no more stop them than we can stop the wind from blowing.

possible means of avoidance?

Worst case: Sending off DNA samples into space in 16 directions?

How bout SF writers? (Not for ways that might work except in the realm of fiction.)

Vulcanologists have been trying to find ways to predict and control volcano eruptions for more than a century, but so far haven't even mastered prediction (much less controlling) smaller, normal volcanoes. Controlling a supervolcano is so far beyond us it's mind boggling.

The biggest problem is really that we can't tell if they're dangerous until the ground starts swelling, and at that point the chamber is charged. Once there's magma in the chamber, ANYTHING we do to breach it has a larger chance of causing an eruption than preventing one.

Seriously, I've enjoyed the clarity and directness of your prose. (Maybe because I was grading freshman papers all day.)

I have a stack of student papers that I need to grade myself, but DU keeps distracting me today :)

...and of course, this will be accompanied by social breakdown, in which humans will be killing each other over limited resources.

After such an eruption, you probably won't want to do much SCUBA diving, and there will be too few people around for the kung fu to be of much use.

If you live through it, though, you might be able to trade that SCUBA knife for some antibiotics. Or food.

--p!

You're probably not going to be too distracted by sex, even if you do find a willing woman.

On the other hand, if you find an abandoned bakery, you could possibly open a cancer clinic. So keep that knife clean and sharp!

:)

--p!

I posted a little about this in another thread today, but there are people who feel that the Mitochondrial DNA studies he used to reach his theory regarding the Toba event and the DNA bottleneck hypothesis are flawed – After reviewing his evidence I have to say I find it compelling, but he’s going to need to answer to his critics with some more research before I buy into it completely, myself.

Fascinating stuff, however!

RTP

according to Science, is about a million to one. So it couldn't happen... could it???

Ever wonder why our ancestors feared the Sky gods, with their thunder and lightning? Of course, it's a scary phenomenon, all the more frightening to children. But there may be more to it than just that. So I present an outlandish, wild-haired, blue-sky, un-peer-reviewed, crazed-as-a-weasel theory about the eruption of Toba, circa 75 kYa.

When a volcano erupts, a huge amount of ash and pulverized rock is ejected into the atmosphere. Vulcanologists estimate that the plume caused by the explosions of Toba, Yellowstone, or Mono-Inyo (East California) topped off at over 50 miles, with a significant amount of ejecta reaching orbit.

One of the things that the people who witnessed the eruption of Mount Saint Helens remarked on was how much lightning there was. It is caused by the action of sextillions of dust, rock, and ash particles rubbing against each other at hypersonic velocity.

I submit that during the eruption of Toba, which occurred at a critical point in the development of Humankind, there was so much lightning that it left a deep mark on the cultural consciousness of the survivors -- a mark made by terror. You don't have to ascribe it to "racial cellular consciousness" -- thousands of years of folklore will do fine.

After a supervolcano eruption, the sky would be filled with lightning, and thunderclaps would come every few seconds. For months. Such an electrical overload would probably affect the human brain, if recent studies with the cognitive effects of electromagnetic fields are any indication. For our less-scientifically-sophisticated ancestors, that could have meant months, maybe years of panic, terror, anxiety, and unexplainable epileptiform episodes.

The lightning, by the way, wouldn't appear to be just individual bolts. There would be immense displays of aurorae and St. Elmo's Fire, colorful glows in strange geometric shapes, and phenomena we can't even begin to imagine.

The legends alone would be horrifying. No one who survived it would be able to forget it -- and many would be driven mad by permanent brain damage.

In our society, it means that our electronic infrastructure would be fried within an hour or two, even the hardened units. Staying in a small free-standing structure, like a residential house, would be suicidal. Metal body parts, like fillings, pins and screws and plates to hold bones together after an accident, even jewelry and piercings could become unexpected attractors of death in the days after a super-eruption.

And if the explosion was energetic enough, and the Moon was overhead the eruption, the possibility of an arc of lightning jumping some 250,000 miles between the volcano and the Moon can not be ruled out. That might actually not be so bad -- it would discharge some of the energy in the atmosphere.

No, it won't be an exciting sci-fi apocalypse with goths and punk rockers and mobsters. It will be more like universal panic.

How about you? How do you feel about thunder and lightning? When you were a little kid? Were you fascinated or fearful? When a thunderstorm blew by on a midsummer's night, did you think it was cool, or did you hide under the covers with eyes screwed tight shut and fingers in your ears, or maybe run into your parents' room in panic?

Those summer storms lasted about 20 minutes to an hour. The post-eruption storm will last days ... weeks.

Sweet dreams.

--p!

Sorry about the language, but.....

I don't know that there's any other word.....

It'd be alright, you'd get used to the lightning fairly quickly and settle down for some light reading I imagine. even a picnic lunch.
Although i'd be doing all that under my bed while holding a teddy bear admittedly.

The metal in the bedframe and the springs, you know ...

Get rid of your watch, jewelry (even the wedding ring, if applicable), and if you have amalgam dental fillings, for godsakes don't open your mouth if you can avoid it!

The lightning would fuse into a universal glow for some time, so it might be good for reading.

I'd try to find a limestone cave -- not a metal mine.

In Southern Africa, a small group of people survived in some deep-cut caves near the seacoast. Scientists think that there may have been as few as 1000 human survivors of the Toba Event out of a world population of several millions.

--p!

1000 survivors world wide is not enough to form a viable population base.
Also there is no archaeological evidence for a mass die-off of the human population 75000 years ago.
Besides, there were several species of human in existence up until 35,000 years ago at least.

Toba catastrophe theory
http://en.wikipedia.org/wiki/Toba_catastrophe_theory

Toba bottleneck
http://www.andaman.org/book/app-r/ch5_bottleneck/textr5.htm

"Estimating how low the number of members of the species Homo sapiens could have been to account for today's uniformity involves a number of variables that are anything but clear-cut. It has been estimated that only 40-600 females (which translates into a total population of less than 3,000 persons; Harpending H.C. et al. 1993) came through the bottleneck. Another estimate arrived at 500-3,000 females (ref. Rogers A.R. 1993) and yet another at 1,000 to 4,300 individuals (Ayala F.J. 1996; Takahata N. at al. 1995). The highest estimate so far has 10,000 females of reproductive age as the minimum (ref. Ambrose S.H.. 1998). Even if the highest estimate is accepted, we are talking about the entire human race numbering no more than the population of a small country town today."

But this kind of genetic science is still not conclusive.
And there needs to be coroberating evidence as well.
In this case a total absence of archaeological evidence makes me more than a little skeptical.
Are you saying that the Toba die-off effected the Sapiens population at a proportionally greater rate than other Homo genuses that existed during this time whose populations were far lower?

"According to Ambrose, this led to a decrease in the average global temperatures by as much as 15°C. This massive environmental change is believed to have created population bottlenecks in the various human species that existed at the time; this in turn accelerated differentiation of the isolated human populations, eventually leading to the end of all the other human species except for the branch that became modern humans."
http://en.wikipedia.org/wiki/Toba_catastrophe_theory

"In the Levant, Homo neanderthalensis re-occupied caves that they had occupied during colder early periods until around 130,000 years ago (OIS6) and then abandoned during the warm and humid OIS5 period to advancing Homo sapiens. Volcanic winter and the following bitterly cold OIS4 after 73,000 years ago saw Neanderthal returning to the Levant and re-occupy his ancient caves. When climatic conditions improved yet again with the onset of OIS3 around 60,000 years ago, Homo neanderthalensis once more retreated to the north - for the last time. Homo neanderthalensis is thought to have become extinct around 30,000 years ago. His last traces fade away on the Iberian peninsula in western Europe. This climatic and population see-saw is reflected in the finds of a number of caves in the Israeli Levant (e.g. Tabun, Skhul , Qafzeh, Amud, Kebara, and others)."

http://www.andaman.org/book/app-r/ch5_bottleneck/textr5.htm#5-1



white dot: Site of the oldest known Homo sapiens (Homo sapiens idaltu, Ethiopia, 154.000 to 160,000 years old.

white X1: the Levant (site of Homo sapiens/Homo neanderthalensis interactions ca. 100,000, 73,000 and 63,000 years ago).

white X2: Toba survivor Homo erectus on Java, Indonesia

white X3: Toba survivor Homo floresiensis on Flores, Indonesia

white-bordered area without hatching: area into which Homo sapiens had expanded from around 100,000 years ago (ref. Stringer C. et al., 1988) until the Toba eruption (...).

red dot: Toba volcano.

red line: The Toba "kill zone" where ash fall was likely to have a lethal and almost instant impact.

essentially quote the same article to support your point.

This theory seems to fit facts that fit and ignore the ones that don't.

Was there a corresponding die-off of large numbers of species world wide at the same time?
How were other primates effected? large mammals? birds? Fish?
The point I'm trying to make is that an 8 year old article without vigorous peer review amounts to speculation.
That said, it does open some intriguing avenues of study,
I just think the theory needs to be better developed.

First of all, nearly all these ideas about prehistoric humanity are fairly new and subject to debate and revision.

I'll address your three points -- all well-made and appreciated -- but the study of human ancestry is still in the midst of a revolution, and will require several more decades to play out.

1. 1000 humans could, indeed, form a viable population base, if they were distributed in a couple of pockets of a few hundred. And while it's possible the die-off took the human population down to 1000, it could have just as easily been 100,000. It was a sharp bottleneck, but very few models have been studied to explain it. I am also aware that a pandemic model could also explain it -- in fact, that was my own "objection" (as a somewhat informed lay person) to the supervolcano idea.

2. There is very little archeological evidence of anything in that time period. An example of this would be studies of pre-Clovis artifacts in the New World. We know that someone was here before the Clovis culture, but the artifacts are still so disorganized that no conclusions can be drawn other than that people made them. (Swanscombe-culture people have been suggested, but there are major problems with that idea, including chronological ones.) It would be more difficult to find evidence of a die-off, too, because such a fast-hitting event would put a crimp in the funeral rites practiced by our ancestors. The corpses would be left to decay and be scattered on the surface, which would make preservation much less likely.

3. The idea that there were "several" human species at that point (and up until 35 kYa) is likewise in doubt. The consensus assignment of Neanderthal people to their own species (Homo neanderthalensis) is fairly new, and has been under contention for decades, anyway. The recent find of "Hobbits" (Homo floresiensis) in Indonesia is also facing well-argued opposition, although the recent damage to the recovered remains and artifacts may slow down that process for years. In addition, Reiner Protsch von Zieten, one of the principal scientists who established many of the commonly-agreed-upon facts about (Homo neanderthalensis) has recently lost his job due to massive academic fraud, theft of artifacts, and plagiarism. (http://skepdic.com/protsch.html)

I enjoy these kinds of discussions, but unfortunately this isn't a forum for academic debate. Besides, I'm an American. We don't study for the sake of Art, Science, or Enlightenment -- we study to prepare for a career, damn it!

But keep 'em coming anyway. One of these days, mass sanity might break out. (An infected little bird told me so. :) )

--p!

I never heard that bit before.

You know, it's been so long since humanity has seen a TRULY destructive natural event that we've forgotten how destructive nature can actually be. Tsunamis, earthquakes, and hurricanes are parlor tricks when compared to supervolcanoes, glacial floods, and asteroid strikes. Our ancestors have watched them all, but we treat them like they're some kind of theoretical occurrence that never really happens.

One of these days Mother Nature's going to call our bluff.

> And if the explosion was energetic enough, and the Moon was overhead
> the eruption, the possibility of an arc of lightning jumping some
> 250,000 miles between the volcano and the Moon can not be ruled out.

:rofl:

The rest sounds quite entertaining though.

Generating the interplanetary thunderbolt would depend on how much charge the column of ejecta could develop. With sufficient charge, I'd say it was a certainty. However, I don't know the math behind electrical discharge across an air, micropressure gas, or vacuum gap dialectric.

On the Earth, this phenomenon would be invisible when it happened, because of the enormous amount of airborne tuff. I also don't think that any satellites could survive such an "energetic" disturbance. And the International Space Station would either be completely disabled or "zapped" itself.

AFAIK, there is some evidence of such discharges between planets, moons, and possibly in star-creating nebulae, though it's obviously tentative and controversial.

Having just thought up this wildly implausible scenario, I'll keep my eyes open for super-thunderbolt references in the future.

--p!

Possibly the finest science fiction short story ever written.

but I have to ask to see either a source, or some calculations. The 250,000 mile insulator of a vacuum between Earth and moon--well, let's just say I am gonna need a LOT of convincing on that front...it's been a decade and a half since I took physics, and currently don't have the ohm value of vacuum and distance memorized I'm gonna go back to the ol' standby V=IR (Voltage = current (I) (in amperes) * Resisatnce (in Ohms)) from this little bit here you can see that you effectively would need an almost infintie voltage due to the almost infinite resistance of a quarter million miles of nothing.

YOu might want to do a little digging about the Io-Jupiter "flux-tube" to find out about planet/moon electrical interactions; although I think even there there is a connection made by ions (most of which come from Io's own volcanic eruptions) trapped in Jupiter's monstrous magnetic field.

In short, I must say I feel privileged to have witnessed the birth of the latest internet theory of doom. (The moon shot lightning bit--not the supervolcano bit!)

But to get back to the original response, your planetary scale lightning storm-theory is interesting--can we see some numbers?

I proposed the idea tongue-in-cheek, realizing, of course, that volcanic eruptions do produce huge amounts of lightning. So a supervolcano could produce that much more lightning, presumably to the point of making the atmosphere (at least the ionosphere) glow.

The flux-tube observation -- yes, that was one of the things I was half-remembering.

Disasters are chaotic events, and I have enough trouble with the math behind even first-degree equations as it is. It might make for an interesting project for a planetary physics or math scholar, but for me, it's been an exercise in imagination. Not quite a gedankenexperiment ...

... maybe more like a verstunkenexperiment. :)

--p!

Certainly nothing like the "Sumatran super-volcano might blow its top at any time"...
:crazy:

There have been 70,000 years of earthquakes in that area and none has triggered an eruption. I guess we simply don't know enough about how super-volcanoes work.

On edit.
More evidence that the journalist didn't understand what the geologist was talking about:

"Professor Cas said super-volcanoes tended to erupt in 2000-year cycles."
http://www.theaustralian.news.com.au/common/story_page/0,5744,12717924%5E30417,00.html

:rofl:

Super-volcanoes greatest hazard on earth

--p!

Toba was the last super-volcano eruption and it happened 74,000 years ago.

I forgot what #1 was, but it happened 25 million years ago.

The "typical" supervolcano eruption in Dr. Cas' schema is much smaller than the Yellowstone blow-outs; the eruptions of Tambora and Krakatau were probably right on a conceptual dividing line between stratovolcano and supervolcano. Mount Saint Helens ejected "only" about two cubic km of tuff. Re-check the graphic in the first message for the details.

The Toba eruption was truly enormous, and the three recent eruptions of Yellowstone were nearly as big; but the biggest blow-out of all probably happened 251 million years ago in what is now Siberia. It nearly ended all life on Earth. Exactly how much bigger it was (or, maybe, "they were") than Toba is still a matter of debate, but two or three orders of magnitude sounds about right.

But even a "little" supervolcano would do a lot of damage.

--p!

Thank God...

Your #1 probably was the La Garita caldera in Colorado which created the Fish Canyon Tuff 27.8 million years ago.

I think that the Siberian and Deccan Traps were created by yet another type of eruption.

It seems that Dr. Cas uses the term "super-volcano" rather loosely, including smaller caldera volcanoes like the Campi Flegrei near Naples (diameter of only 13 km).

It completely disturbed the natural order of the universe!;-)

(I'm STILL NOT OVER IT dammit!)

It's worth whatever price we have to pay!

Avoidance? (Channelling rivers and lakes into nuclear blasted crevasse? Diverting pressure in separate events designed to eliminated catastrophopic eruption?)

After? (Burrow beneath ground with artifical greenhouses?)


Obviously someone's considered this, at least as a science fiction story. Any serious suggestions?

It would take a lot of science fiction to deal with it.

"Batten down the hatches" seems like the more appropriate response.

--p!

Headline for the New Millennium: Natural Selection in Action

It's not just for idiots. Kids who get cancer and die before they can grow up and make babies themselves are just as naturally-selected as fools who die from the results of their stupidity.

In reference to a supervolcano eruption? I don't think it would be possible at all to stop one with the technology we have now. They're huge, and the energy they release is enormous. But given time for evacuating the area and planning for dealing with the tuff, the loss of a growing season, and other difficulties, it would still be calamitous but not put us in peril of extinction.

--p!

Take Yellowstone as an example. If the chamber is 50KM across, you'll have to dump in a LOT of water to cool it off. That much water dumped onto that much lava would cause an explosion so loud it would knock out windows in L.A.!

Diverting pressure doesn't help much either because uneven lessening could actually weaken the integrity of the rock above the magma chamber and precipitate a collapse itself.

After is simple, on paper. Store enough food to last you for six months, and enough seed to plant a farm when the sun comes back out. Pack enough weapons and ammunition to fight off the hungry people who are going to try to take it from you. A good off-road vehicle and a lot of fuel might be useful too. Beyond that, you shouldn't need much. Just about anything else you need, or the parts to build it, should be readily scavengable from the wreckage of the cities.

Don't move near any rivers...the unmaintained dams upstream will eventually collapse. Don't move downwind of any nuke plants...the reactors will run on auto pilot until something goes wrong, but one by one they'll all melt down. Don't move near any petro or chemical plants...they'll eventually all spring leaks.

I mean it.

If it's this in fact (and I don't doubt it for a minute), I wonder what we've done with the event imaginatively--there have to be trashy science fiction stories where, ofr instance, Captain Hunkster diverts a comet to break the magma shell and disperse the destructive agencies of the dire event.