Once, around 74,000 years ago, the Earth had a bad day. A very, very bad day.
So bad in fact, that it was one of the worst days in the Earth’s long history. And it was caused by something that happened just over 300 kilometres west of modern-day Kuala Lumpur.
In what is now Lake Toba in North Sumatra, Indonesia, the land had been swelling threateningly by a few metres a day, with searing hot gases seeping through its crackling, venous vents. At the time, Sumatra and Peninsular Malaysia were not distinct land masses separated by the Malacca Strait. Rather, they were both part of a gargantuan, prehistoric, subcontinental peninsula called Sundaland.
After millenia of accruing immense geothermal pressure, the thin layer of crust that entombed the churning, searing subterranean magma started slowly rupturing, resulting in harmonic tremors – a release of seismic energy that acts as the final warning before the Earth rains hellfire on its surface inhabitants.
Suddenly, Toba blew off its dome, exploding with more power than a million Hiroshima atomic bombs. Its volcanic explosivity index (VEI), a scale to measure the relative explosivity of volcanic eruptions, would have recorded a magnitude 8 – the highest rating possible.
In its mephistophelian rage, it belched out over 2,800 cubic kilometres of scalding hot ash and pulverised rock, in addition to asphyxiating dust and poisonous sulphur. Its eruption column reached tens of kilometres into the heavens.
Once it penetrated the stratosphere, it dispersed radially, forming a tenebrous, menacing mushroom cloud of epic proportions. And all around it, the land convulsed violently, emitting an ear-splitting, primal roar.
It was the largest eruption Earth had experienced in two million years.
All the largest volcanic eruptions in recorded history – Krakatoa, Tambora, Pinatubo and Vesuvius – pale in comparison, being at least a hundred times less powerful
than the Toba supervolcanic eruption.
But this was only the beginning. The worst was yet to come.
Just moments after the sky-piercing eruption column formed, a pyroclastic flow followed. An avalanche of gas and volcanic matter, travelling at hurricane speeds of hundreds of kilometres an hour generating heat of over 1,000 degree celsius, descended upon the surroundings, desecrating everything within its expansive reach.
The eruption was of such intensity that its Stygian pyroclastic flow reached the height of modern skyscrapers. Any lakes in its path were boiled out of existence.
Had prehistoric humans found themselves in its treacherous trajectory, they would not have been able to outrun it or hide from it. There was no recourse, no escape. Nothing in its extirpative path could survive.
First, a hail of incendiary volcanic matter would have rained on them, cutting through their skin like butter and puncturing their internal organs. Those who escaped the initial volley by hiding under a boulder or inside a cave would still have ended up inhaling its incandescent gasses and torrid ash. This would have combined with the moisture in the trachea and lungs to form a substance with a concrete-like consistency, clogging up their airways.
Simultaneously, the water in their tissues would have boiled off while the intense pressure exacted by the expanding hot gases would have literally made their heads explode, popping their skulls open.
What a way to die.
The noxious ash cloud blotted out the sun, causing worldwide temperatures to plummet anywhere from three to ten degrees celsius in the next few years, triggering a years to decades-long volcanic winter.
For perspective, more than a century of human-induced pollution and environmental degradation has only managed to cause a less than one degree celsius rise in global
temperatures today.
Some scientists think that the Toba supervolcanic eruption might have exacerbated the ice age – one that the Earth only escaped around 14,000 years ago after what increasingly seems like one or more cataclysmic asteroid impacts, which helped reverse the ice age and set the Earth on the warming trajectory it’s on now.
Even though Toba’s devastating pyroclastic flow probably did not reach prehistoric Malaysia, it was still the unfortunate recipient of tonnes upon tonnes of volcanic ash that enshrouded the sky and enveloped the land. The sulphur dioxide, that volcanic ejectile is abundant in, combined with water vapour to form sulphate aerosols, a
poisonous gas, causing acid rain.
This toxic ash cloud travelled far and wide, descending on and smothering our ancestors, including those at Kota Tampan, in modern-day Lenggong Valley, Perak. Evidence of this was found during an archeological dig in 1987 which revealed the site of a paleolithic stone tool workshop which held a staggering 50,000 stone artefacts right under a thick layer of volcanic ash that the Toba eruption had deposited in the area. This indicates extensive human activity prior to the eruption.
Initially, scientists were unsure of whether the tool workshop was the work of anatomically modern humans or an earlier species of humans, but the similarly designed pebble tools found buried with the 11,000-year-old, anatomically modern Perak Man found in the Lenggong Valley strongly supports the hypothesis that the Kota Tampan prehistoric society was indeed populated by modern humans.
This is remarkable as it suggests that the first modern humans making their way out of Africa had already reached and settled down in prehistoric Malaysia at least 74,000 years ago, making it the oldest-known society in our country.
It also makes the stone tool workshop in Kota Tampan, Lenggong Valley, one of the oldest, if not the oldest precisely dated evidence for the presence of modern humans outside of Africa.
Unfortunately the Toba eruption sounded the death knell for the Kota Tampan prehistoric society, burying them under up to a staggering 10 metres of ash, most likely annihilating their thriving culture.
But according to Oxford genetic anthropologist Stephen Oppenheimer, it wasn’t all gloom and doom – at least not entirely. He says: “Kota Tampan was just at the eastern edge of the great ash fall and there would have been survivors in the rest of the Malay Peninsula re-occupying the Lenggong Valley – bearing the torch of humanity into the modern age.”
This was fortunate, as evidence suggests that the eruption could have been so catastrophic that it might even have reduced the entire global human population at the time to about 1,000 breeding pairs, leaving our budding species teetering on the brink of extinction. This was due to the double whammy of the mega eruption and the subsequent deep freeze it engendered that would have undoubtedly caused a global famine.
This theory is given credence by the fact that there is a genetic bottleneck in both Asia and Africa around 71,000, indicating a large pool of humans rapidly dwindled before their gradual re-expansion. This corresponds near-perfectly with the Toba eruption.
However, this is a hotly contested theory and far from settled.
But one thing’s for sure – the Toba supervolcanic eruption was undoubtedly the biggest known calamity to befall our species in our approximately 200,000-year run.
We should thank our lucky stars that it wasn’t a teeny bit more destructive than it was, for if that had been the case, I might not be here to tell its story and you might not be here to read about it.
The views expressed are those of the author and do not necessarily reflect those of FMT.