The Lost Eruption

"...at last the mountain Kapi with a tremendous roar burst into pieces and sank into the deepest of the earth. The water of the sea rose and inundated the land... The water subsided but the land on which Kapi stood became sea, and Java and Sumatra were divided into two parts."

~ Javanese Book of Kings

Historical records can paint a terrifying image, but those of legend can be all the more frightening. But there are instances where the line between myth and fact can become slightly distorted. Take as an example the Native American mythology of the Thunderbird.

"At the time of the Great Flood, Thunderbird fought a long, long battle with Killer Whale. He would catch Killer Whale in his claws and start with him to the cave in the mountains. Killer Whale would escape and return to the water. Thunderbird would catch him again, all the time flashing lightning from his eyes and flapping his wings to create thunder. Mountains were shaken by the noise, and trees were uprooted in their struggle. Again and again Killer Whale escaped."

Under normal circumstances, this would seem to match up in fashion with other flood mythologies from around the world. Except that geological records have shown a correlation between this mythology and a Japanese record from 26 January 1700 showing a tsunami hitting the islands, but with no corresponding earthquake. The earthquake, estimated at 9.0 on the Richter Scale, had in fact been generated across the Pacific Ocean, in the Cascadia Subduction Zone.

While many would never call into question that this event occurred, it would hardly convince skeptics that the Book of Kings could be correct in its assertions. The book tells that the two islands had once been a single mass, split in half by the explosion of a single mountain, around 416 AD. While there is no evidence yet located of such an eruption, an eruption large enough to tear a gaping hole in the island, creating what is now the Sunda Strait should have left some mark behind.

Though nothing is shown from 416, there is a slight curiosity in both Antarctic and Greenlnd ice cores around 535 AD: a large spike in sulfur dioxide content, far larger than any other in recorded history. Such a spike could only be generated from a volcanic eruption, and one of such magnitude, it would cause far-reaching, perhaps global, consequences.

And the records exist, showing a severe series of meteorological events at the same time. In 536, the Byzantine historian Procopous recorded that "during this year a most dread portent took place. For the sun gave forth its light without brightness." Other events have been catalogued worldwide, including crop failures from Ireland to Sweden, snow in August in China, and a severe drought which led to the collapse of the Moche natives in Peru.

While there is no conclusive geological evidence showing where this eruption could have been, there is that passage from the Book of Kings, and its inference to the Sunda Strait. What is does not mention specifically is the monster that resides there to this day.

On 27 August 1883, the volcanic island Krakatau erupted with such a force, the explosion was heard over 3,000 kilometres away in Perth, Australia. Tsunamis and pyroclastic surges slammed nearby shorelines, killing 36,417 people. Devastated by its own destructive force, fully two thirds of the volcano collapsed in on itself, forming a caldera. From such a ferocity, people could easily believe the volcano would never return. But as we all know, history often repeats itself.

In 1927, the Sunda Strait were disturbed once again with a new power rising. Anak Krakatau now rises over a thousand feet above the strait, with no signs of slowing down. But if this new volcano had risen from the ashes of its father, could Krakatau in turn have risen from the grave of something even larger?

The rating scale for volcanic eruptions, the Volcanic Explosivity Index, reserves the top rating of 8 for volcanoes which throw out more than 1,000 km³ of material. It is this class alone which stands uncontested for its capacity to change global weather. The Toba eruption, 74,000 years ago, has been accused of changing the climate so radically, all but two thousand members of the early species of man were wiped out.

47 eruptions of such magnitude are known to have happened, from the Pacana Caldera of Chile, to the famous Yellowstone eruption 640,000 years ago. But through all this, I find myself asking an ominous question: did we have one slip past right under our noses?

UPDATE: 23 August 2012, 13:57

A recent e-mail from a representative of the United States Geological Survey has confirmed privately that there is "substantial, yet still circumstantial evidence" for a VEI 7/8 eruption of Krakatau in 535 AD.