Lake Toba today
In North Sumatra, Indonesia, Lake Toba is 100 km long, 30 km wide and contains 240 cubic kilometres of water. It’s the residue of the biggest bang in the past 2 million years, the Mt Toba supervolcano eruption of 73,000 years ago.
That little bunger put 2800 cubic kilometres of rock, ash, and pumice into the air. That’s 112 times the 25 cubic kilometres produced by Mt Pinatubo in 1991 and Krakatoa in 1883.
An interesting question is, how much of the human race did Mt Toba wipe out?
Wikipedia says that “the Lake Toba eruption plunged the Earth into a volcanic winter, eradicating an estimated 60% of the human population (although humans managed to survive, even in the vicinity of the volcano.)”
Professor Martin Williams from Cambridge and now emeritus professor at the University of Adelaide on The Science Program last year seemed to be taking the view that the human race was all but wiped out apart from a population of a few thousand in Africa. I thought that seemed pretty straight forward until I started googling. One of the main pieces of evidence for a contrary view seems to be the discovery by Michael Petraglia, one of Williams’ colleagues Cambridge, of stone tools at a site called Jwalapuram, in Andhra Pradesh, southern India, above and below a thick layer of ash from the eruption of Toba.
The merits of this claim get a good workout at Anthropology.net.
As a bloke without any science qualifications who just wandered into this territory I’m probably not entitled to a view. Nevertheless it seems to me that Williams is probably right, though he doesn’t claim the case has been conclusively proven yet. The artifacts in India before and after the layer of ash need not have been left by the same people. In fact the earlier ones may not have been left by homo sapiens at all.
In any event it does seem clear that Toba caused a population bottleneck and that the human race is remarkably homogeneous genetically. Nevertheless populations of homo neanderthalensis survived, presumably in Europe. So too did homo floresiensis, presumably right there nearby.
There’s more on the subject at Wikipedia’s entry on the Toba catastrophe theory.
The Toba eruption lowered the world temperature by as much as 5C, a huge abrupt change when compared to the 0.5C or so by Mt Pinatubo. More particularly it caused a prolonged drought lasting about 1200 – 1500 years, I gather at least in the Bay of Bengal.
The question now is the likelihood of a repeat performance by Toba or another supervolcano. Williams in an extended version of the interview says that such an event could happen, but it seems we should be OK for some thousands of years. It’s a case of millennia rather than centuries, says Williams. Alert but not alarmed is the go.
Other cases of volcanic winters include the extreme weather events of 535-536 the cause of which is unknown and the eruption of Mount Tambora in 1815 (100 cubic kilometres) which caused the Year Without a Summer which destroyed crops in Northern Europe, the American Northeast and eastern Canada in 1816.
It’s interesting that Gwynne Dyer in his book Climate Wars can’t resist the temptation to include a supervolcano eruption, indeed of Toba, in one of the future scenarios he pens.
The time is 2039. The Philippines and Indonesia have become impatient with the attitude of other countries, especially Western governments, which rejected the notion of geoengineering, not because of fear of the environmental consequences, they feared a fresh outbreak of green terrorist bombings. Bankrolled by China, the Philippines and Indonesia began releasing high-altitude balloons to place one megatonne of sulphur into the stratosphere successfully dropping global temperature by 1C in 2040.
At that time Toba decided to clear its throat burping a mere 550 cubic kilometres into the atmosphere. It was enough to reduce the temperature another 3C or 2C lower than it was in 1990. Crops specially bred to cope with the heat failed everywhere. World grain production fell by 35%.
While no more than three or four hundred million people died directly from starvation, most were from the poorer countries in the tropics and subtropics. The political violence and social breakdown that ensued plunged a third of the world’s population into failed state status. While the temperature returned to ‘normal’ by the following year another 3-400 million died over the next five years from civil war, mass migration and genocide.
Dyer does not claim that his scenarios will be accurate, just that a lot of bad stuff is bound to happen.
What we need to finish with is a nice big picture of Mount Pinatubo going off:
Mt Pinatubo erupting
Imagine an eruption 112 times as big as that!
Clearly, the only sensible risk mitigation strategy here is to establish human settlements somewhere other than this little rock.
Interesting post Brian, but wouldn’t Yellowstone National Park (if it blew its lid) be an equivalent “big bang” to lake Toba.
(Quick quiz: The big bang theory was first postulated by:
(1) James Bond
(2) Madonna
(3) The mayor of Hiroshima when he said “WTF was that?”)
Great post Brian.
Peter mentions Yellowstone which was the star in a BBC docudrama on supervolcanoes. Some info on Yellowstone and the likelihood of an eruption here.
Either of the volcanoes having a major eruption would be pretty nasty for us.
Brian,
There’s a history book came out a few years ago called Catastrophe which I think deals with the 353 AD event. (I think it was also a TV doco) I bought it for a friend of mine whose right into End of the World scenarios but read it before I handed it over. Intriguing.
As a side point – I remember going on holiday to Toba in the mid 1970s. Beautiful area if you ever get a chance to go there.
Brian, how does the more recent NZ supervolcano (wiki: Lake Taupo, North Island, New Zealand – Oruanui eruption ~26,500 years ago (~1,170 km3)) rate? It is less than half the size of Toba but should have had a measurable effect.
In the last million years two of the four supervolcano events have been in NZ. Perhaps we have more to fear from the Shaky Isles than Indonesia?
aidan,
if Lake Taupo was ~26,500 years ago… by the time the ash had circled the Earth once and reached Australia, was there a major impact on our indigenous inhabitants? Or forests, kangaroos, birds, etc??
Stephen Oppenheimer is the author of “Out of Eden” which traces, via DNA analysis, the migration of humans around the planet since the original ‘out of Afica’ event.
He has quite a discussion on the Toba event and its impact on humans in the area as suggested by archeological evidence in Malaya and elsewhere and DNA analysis in the region.
He also discusses the probable time of arrival of humans in Australia related to the Toba event, migration here seems a little later than the time of the explosion, by a few thousand years, and from people who originated in Africa itself much earlier and travelled to here in stages along the ‘beach trail’ taking thousands of years to do so.
I think I read elsewhere that the impact on Aussie flora/fauna would have been minimal because the effect was concentrated more to the west of Toba rather than in our direction. Local impact of these events seem to be greater than global. Don’t quote me on that.
One of the problems for the relevance of all this sort of stuff to Australia is the relative paucity of research here.
I spent a couple of weeks at Lake Toba, on the island mainly, about 15 years ago [geez I didn't realize it was so llong ago] its a really nice place.
Aidan – perhaps we better tow NZ away from us? Maybe next to France?
I get the impression that Brian would really get into Stephen Baxter’s novels which entail various sticky ends for the Earth and/or Homo Sapiens. Baxter explores the theme of this post in this book
Thannks for the post Brian. It does indeed seem that there is a range of things that could completely fuck things up for all humanity, rendering inconsequential my worrying about superannuation and whether or not to install a swimming pool to cope with the Alice Springs eternal summer (35 today and projected to be so for the next week- it will be April then!). This is good as I could worry about the merits of filling a hole in the backyard with water from an aquifer that I have heard only has 300 years of water left in it at present usage rates (disclosure if we get a pool we will also be installing tanks- yes I know madness not to have them already but you can only do one thing at a time).
It is amazing how you can jump around inside wikipedia finding more and more devastating events. Is it designed to be the biggest and best of kinda site? My random hopping left me at the Chicxulub crater. Does anyone know of anything more devastating than a 10km rock slamming into the earth (apart from the big bang- but I don’t actually believe in that)?
Roger, this will cheer you up greatly.
Super volcanos? In Jellystone? Quick Boo Boo, grab the pick-a-nick baskets!
Robert, for the cost of establishing self-sustaining human settlements elsewhere we could not only resolve the damage we’re doing to the planet’s life support systems, but have plenty of change left over to bunkers safe enough to survive events like these.
In virtually all cases the danger from these events is not that they would wipe out humans as a species, but that they would kill billions and endanger the structure of society for everyone else. Settlements in space won’t fix that.
Stephen L: I’m not suggesting it as a short-term strategy.
Give it another century or two, and the cost won’t be an issue – assuming we don’t kill ourselves in the meantime.
You’re such a Cassandra, Brian!
Don’t recall where I saw it, but the events of 535-6AD were volcanic in origin,and have been tentatively linked to the caldera forming eruption of Rabaul volcano about 1400 years BP.
Can anyone date the huge caldera in northern NSW centred around Dorrigo. It is a significant sight seen from the air.
A check of Dorrigo national park reveals Mt Ebor in a volcanic erruption some 18 million years ago.
youse outdid yourself Brian.
Now you got me worried.
Pablo, a lot of Australia’s volcanic activity was tens of millions of years ago. So Ebor, Mt Warning etc a pretty much safe for a now (even though they were huge volcanoes in their day).
Mt Napier in Victoria is the most recent volcano to blow its top. I believe that was about 5,000 years ago.
Yep, that’s me all over. I don’t have another act to follow up, so I’ll have to go back to global warming.
Sorry I haven’t been here all day. I went out and bought a new secondhand ute, I did, and besides it’s my birfday.
pablo, I remember being very impressed with the Warrumbungles which I think were active as a volcano 13-17 Million years ago.
Mercurious, I do like the odd bit of gloom. I think it is the stupendous scale and power of nature, in which we seem so vulnerable. As a species we’ve been around only the blink of an eye and are very likely nearer the end than the beginning if you start from, say, Lucy, the hominid Australopithecus afarensis which lived between 3.9 to 3 million years ago. Compared with where the universe has come from and where it’s going to it’s fireflies in the night really.
Actually I was thinking about doing a post on holes that open up and swallow your car as you drive along. It happened in Ipswich the other day, but it’s quite common around the world.
Something else to worry about
There’s more! A cane toad in Melbourne! Don’t miss the picture gallery.
there is a range of things that could completely fuck things up for all humanity
Not least of which is humanity itself, of course
I remember Mt Pinatubo well. Some of the volcanic fallout (is that the right term?) actually wound up in the suburbs of Sydney. I have a photo of the family dog from 1991 lying out in the back yard surrounded by this red stuff, which was apparently blown all the way from Mt Pinatubo.