About 73,000 years ago (74,000 by some estimates) a massive volcano on the Indonesia island of Sumatra erupted with a volcanic explosivity index (VEI) of 8. Such an eruption is so severe in its effects it basically would cause the deaths of billions of people today. New evidence finds that Toba's eruption caused deforestation in what is now central India.
CHAMPAIGN, Ill. — A new study provides "incontrovertible evidence" that the volcanic super-eruption of Toba on the island of Sumatra about 73,000 years ago deforested much of central India, some 3,000 miles from the epicenter, researchers report.
The 800 cubic kilometers of ash ejected by Toba compares with the mere 160 cubic kilometers ejected by the 1815 Tambora eruption. The larger Toba eruption caused an ice age that lasted 1,800 years.
The volcano ejected an estimated 800 cubic kilometers of ash into the atmosphere, leaving a crater (now the world's largest volcanic lake) that is 100 kilometers long and 35 kilometers wide. Ash from the event has been found in India, the Indian Ocean, the Bay of Bengal and the South China Sea.
The bright ash reflected sunlight off the landscape, and volcanic sulfur aerosols impeded solar radiation for six years, initiating an "Instant Ice Age" that – according to evidence in ice cores taken in Greenland – lasted about 1,800 years.
During this instant ice age, temperatures dropped by as much as 16 degrees centigrade (28 degrees Fahrenheit), said University of Illinois anthropology professor Stanley Ambrose, a principal investigator on the new study with professor Martin A.J. Williams, of the University of Adelaide. Williams, who discovered a layer of Toba ash in central India in 1980, led the research.
We are not prepared for such an event today. Even 5 or 10 years to prepare could at most save a small fraction of the human race.
The 1815 Tambora VEI 7 eruption caused crop failures for 2 years. Imagine that happening today with nearly 7 billion humans using a much larger fraction of total planetary biomass. If a VEI 7 eruption could somehow be predicted several years in advance then industrialized nations could stockpile enough food to make it thru the crop failures. But poorer nations would face starvation on a scale not seen in the last 100 years.
Since geologists can't predict VEI 7 and up eruptions years in advance I do not expect we'll possess the ability to handle such an eruption until nanotechnology enables such huge increases in living standards that it becomes possible to very cheaply produce huge amounts of excess food and very cheap ways to store it for years.
By Randall Parker at 2009 November 23 08:58 PM Dangers Natural GeologicalOne word ... Yellowstone.
"The volume of volcanic rock produced by the first Yellowstone caldera eruption was about 600 cubic miles-about 17 times more than Tambora"
http://www.yellowstonenationalpark.com/calderas.htm
It erupts every 600,000 years or so and last one was 640,000 years ago.
Bruce,
Yellowstone's last eruption was 1000 cubic kilometers versus 800 for Toba. So, yes, really big.
I figure if I live until Actuarial Escape Velocity is achieved and then I survive the Singularity then I'm going to construct a place that can allow my cybernetic self to survive the next VEI 8 eruption.
Another possible use for nanotechnology would be collection of the ash particles from the atmosphere after an event such as this.
I saw the following claim:
" Newer evidence indicates that after populating much of Europe and Asia there was a dieoff (likely climatic) and all modern humans can trace their genetic ancestry to a fairly small group of early humans who survived at the southern tip of Africa around 70'000 years ago. Supervolcano Toba in Indonesia exploded around 73,000 thousand years ago. It killed almost all humans. Less than 10,000 survived in Africa.
No references...
Nick, A die-off caused by Toba has been much debated by anthropologists. I'm not surprised there isn't a cite. I could ask an anthropologist for a sense of where the debate is if you are interested.
Randall,
I would be curious too - regarding that claim - as I have heard much the same and thought it was generally accepted now as a major incident in our ancestry.
Of all the natural disaster scenarios - I must admit - Volcano's scare the crap outta me - it certainly seems like we should be putting more resources into how to prevent (or at least predict) such a large scale calamity...
Maybe we should force all banking instutions to have their headquarters within potentially active volcanic zones - if they want to maintain their tax breaks - and before long the govt. will be pouring taxpayer money into investigating the problem.
What a rediculous, short sighted, species we still are...
Lono,
Banks obviously do not believe that reckless policies are anything to worry about. Why would you expect them to worry about volcanoes? I'm sure the top execs would think they'll be long retired by the time of the next eruption.
Heh Heh - Touche'!
Seriously though - not being a geologist - is their any force or action of man that can potentially dampen or reroute the erruption of a volcano - yet alone a super volcano?
Don't they usually (and paradoxically) use nukes in the movies to prevent these disasters?
Lono,
I've yet to read about a serious way to stop or reduce a volcanic eruption. Nukes? I have no idea. Haven't seen geophysicists propose this. Only saw it in Hollywood movies.
I'm curious to know what could be done.
I'm also curious to know what happens when a VEI 8 happens in the ocean. Better or worse than on land?