I was intrigued by several articles that were just published this month in the journal Quaternary International . The entire May issue is devoted to research devoted to understanding history and implications of the Toba volcano super-eruption. The Toba volcano is found near the center of Sumatra, Indonesia. It is not much of a volcano anymore because in the past it completely blew its top and then collapsed into what is called a caldera which then filled with water to form a huge (100km x 30km) lake. It has been estimated that at least 2800 cubic kilometers of material was thrown into the air during the explosion or series of explosions. To put that in perspective the Krakatoa volcano threw just over 2o cubic kilometers of material into the air some of which circled the globe causing dazzling sunsets in Europe. Mt. St. Helens in Washing State only threw 1 cubic kilometer or less into the air so this Toba volcano was some 2800 times as large! In fact, the Toba super-eruption may be the single largest volcanic explosion in earth’s history.
——Also see follow-up article to this one – The Toba Super Eruption and Polar Ice Cores —-
The extent of this eruption is difficult to comprehend and can hardly be overstated! It was MASSIVE but how do we know? The size of this explosion is estimated from both the vast hole it left where the volcanic peak must have once stood (see the picture above of the lake that now resides in what is left of the volcano) but also from measurements of the ash layer, called tuff, it left over all of southeast Asia and even most of the Indian subcontinent. This ash layer can be over 1000 feet thick near the volcano to several inches as much as 2000 miles away. Signs of this volcanic eruption are even recorded in the Greenland Ice cores. A thick layer of ash several inches to a foot thick is found in cores pulled from the floor of the Indian and South China Sea. This ash layer can be assigned with little doubt to this particular volcano based on the ratio of a number of chemicals that make up the magma of the Toba volcano.
Studies (see references below) of the most recent Toba super-eruption tuffs called the YTT (youngest Toba tuff) suggest, not surprisingly, that this event effected the climate of the earth by blocking the sun resulting in lower temperatures and less rainfall, causing wide scale changes in vegetation beyond even where the ash fell. Where the ash did fall, dramatic changes in vegetation structure can be inferred. Vegetation analysis of pollen and plant parts found in sediments below the ash layers in India and Indonesia have been performed and in sediment cores from the Indian ocean where fine scales pollen analysis can be performed to see what pollen was drifting in the air over the ocean from the continent and settling to the ocean floor. What these data strongly suggest is that there were widespread tropical forests and dense deciduous forests with little grass in most of India prior to this volcanic eruption. Above the ash layers much dryer conditions prevailed with grasslands contributing to the fossils in the sediments immediately above the ash layers.
When did the Toba Super-Eruption Happen?
You might be wondering, wow, very interesting, but why haven’t I heard of such a HUGE event in Earth’s history? Well, I haven’t said when this occurred. Dating of the Toba tuff layer and sediments above and below the tuffs from many locations have all yielded a date of around 74,000 years ago. This corresponds with small global climate changes recorded at the same dated age on the Greenland and Antarctic ice cores.
With respect to young earth creationism this date is a problem but irrespective of radioactive dating, I think it is clear that this layer of volcanic tuff is not particularly young because it is found many tens to hundreds of feet under other sediments in many places in Asia and under 10 to 50 feet of sediments in sea floor cores. Ok, you might be thinking this is just another example of a dating problem and some apparently old features of the sedimentary record and so not really that profound. Most YECs acknowledge the existence of super volcanoes in the past but they always propose they happened during or right at the end of a global flood (see refs for some examples).
So is this just a case of another volcano that caused devastation during a time that was catastrophic anyway? Not at all! There is another aspect of some very recent research on the Toba ash that suddenly has made this particular volcanic event of much greater significance to the creation debate.
Toba Super-Eruption and Human Migration
The YTT (youngest Toba tuff) ash layer is particular relevant to any discussion of human origins and migration and is why this ash layer has been studied so intensively the last 5 years.
Why, because in a valley in southern India (see picture to right) where this ash layer has been preserved very well, more than 200 stone artifacts have been found in layers of sediments just BELOW the ash layer. 500 miles to the north there is another site where this ash has been investigated and evidence of human occupation below the ash has been found there as well. The inescapable implication of these stone tools is that people were living in India when the volcano blew its top. For the past three years anthropologist have hotly debated who these people were that left these stone tools at this location and whether they were all killed by the volcano and had to repopulate southeast Asia from Africa/Middle East again or if they survived in small numbers and repopulated the region but that debate is not my primary interest here.
Implications for Young Earth Creationism
This massive and apparently world-altering volcanic explosion cannot be explained away as having happened during the global flood as are many other super volcanic events, such as those of the Yellowstone caldera, by YECs. Here we have an example of a volcano that must have obliterated nearly all life on Sumatra when it blew and likely completely deforested most of Indonesia, the Philippines, Thailand and even parts of India. Massive layers of air-borne ash would have killed the majority of animals in this entire region. But rather than try to explain this as happening while Noah and his family where safe inside the Ark the evidence of humans occupying a site before this massive volcanic eruption means that this volcano has to have blown its top in the very recent past according to the YEC time line. This is because most Creationists argue that all humanity was gathered together at Babel and it is expected that Babel didn’t occur until several hundred years after the Flood. Logically, then these stone tools could not have been dropped at this location in India until well after that point. Hence, for young earth creationists, the volcano didn’t destroy Sumatra until well after the dispersal of peoples from Babel. So far I have been unable to find a single comment by young earth creationists about the significance of these artifacts apart from a reference (see below) by Brian Thomas at ICR who uses the presence of artifacts as evidence that these people were fully human and not some other species but seemed to be quite unaware of the implications of the position of these artifacts for the creationists’ time-line.
There is so much more that could be said about this site and its implications but I don’t want to distract from the main point: Within a young earth worldview, this is almost as close as you can get to proof that people had already migrated long distances and had to deal with a major catastrophe that could not have been part of a global flood event. So, when did these people live? How did they get there? How could much of this ash be covered by many dozens to hundreds of feet of sediments including many other “ancient” sites of human occupation that predate any written record? Why did the people who lived here only have very crude rock flaking technology if they had just dispersed (probably in less than one lifetime) from building a sophisticated tower of Babel? How could this massive eruption not have been noticed by people all over the world and been recorded in human history? When it comes to the human origins, there are no simple answers to these questions for anyone who wishes to compress these events into a short time window.
References, Sources and Interesting Links
This is a link to the Article index for the May issue of Quaternary International. If you have access to the articles there is a wealth of information here.
Middle Paleolithic assemblages from the Indian subcontinent before and after the Toba super-eruption. M Petraglia, R Korisettar, N Boivin, C Clarkson… Science 6 July 2007: Vol. 317 no. 5834 pp. 114-116
A science direct highlight of research on the human occupation of this region at this time.
Michael D. Petraglia, Ravi Korisettar, J.N. Pal. The Toba Volcanic Super-eruption of 74,000 Years Ago: Climate Change, Environments, and Evolving Humans. Quaternary International, Volume 258, 1 May 2012, Pages 1–4
http://www.icr.org/article/supervolcanoes-mount-st-helens-eruption/ – Supervolcanoes and the Mount St. Helens Eruption, By Steven Austin. Here Austin presents an argument for supervolcanoes during the flood with gradual reduction of force after the flood to the present.
http://www.icr.org/article/early-advanced-human/ – Brian Thomas of ICR makes comment on the Toba eruption but doesn’t say when and doesn’t mention the volcano’s power. He just uses it as an example of humans in India being advanced (advanced apparently means only capable of making stone tools?!).