The disaster that nearly wiped out humanity

A Spanish-language blog has picked up the story of the earliest disaster featured in my book A Disastrous History of the World (Historia Mundial de los desastres).  A disaster that may have come close to wiping out the human race.   http://www.taringa.net/posts/info/15902116/La-erupcion-que-estuvo-a-punto-de-aniquilar-a-la-Humanidad.html

It was a huge volcanic eruption more than 70,000 years ago at what is now Lake Toba (pictured above) on the Indonesian island of Sumatra.   It is thought to have been one of the most powerful ever, at about 28 times the strength of the Tambora eruption of 1815, the biggest of modern times.

The eruption itself must have been deadly enough, but much worse was the volcanic winter that followed.   The ancient volcano spewed out an estimated 670 cubic miles of debris that dimmed the sun’s rays for six years.

As catastrophic global cooling resulted, the world’s estimated human population at that time of a million was reduced to perhaps just 10,000.   The eruption gouged out a vast crater which filled with water to produce picturesque Lake Toba, now a noted tourist destination.

Volcanic ash

Iceland’s second major volcanic explosion in less than a month (see also my blog of March 21) has led to the cancellation of all flights across the UK for the second day running. Ireland, the Scandinavian countries, Belgium and the Netherlands also closed their airspace yesterday, while France and Germany suffered severe disruption.

It is a reminder of how the ash flung out from a volcano can be even more devastating than the eruption itself. The eruption of Laki on Iceland in June, 1783 produced a cloud that spread as far as Moscow and Baghdad. In England, it turned the weather bleak and foggy while in Alaska, the Kauwerak tribe dubbed 1783 “the year summer did not come.” There followed one of the worst winters in 250 years in Europe and America. According to some estimates, the eruption indirectly caused up to 200,000 deaths.

The effects of Laki were probably exacerbated by the eruption of another volcano two months later – Mount Asama in Japan. It lowered temperatures, causing crop failure and famine, with harvests not recovering for a decade.

Indonesia’s Tambora went up in smoke in 1815, producing another year without a summer. Snow fell in Canada and New England in June, and in England in July. The famine and disease of the aftermath were deadly enough to kill perhaps 80,000 in Indonesia and 200,000 in Europe. Alarming, but not as deadly as the prehistoric eruption at Toba (also in Indonesia). The volcanic winter that followed is reckoned to have wiped out 99% of the humans then walking the earth.

Coincidental quake

The earthquake that has just devastated the Indonesian island of Sumatra was a separate event from the earlier Pacific tsunami that hit Samoa (see yesterday’s blog) though some experts believe the Samoan event may have brought the Sumatran quake forward by a few days.

At least 464 people have been killed on Sumatra, though an official at Indonesia’s disaster centre predicted the death toll could eventually run into thousands. The initial shock came beneath the sea, 50 miles north-west of the city of Padang. An eye-witness said many concrete buildings had collapsed and that fires were burning in the ruins.

Indonesia is in the Pacific’s “Ring of Fire”, the most seismically active region on earth, which suffers up to 7,000 earthquakes a year. Five thousand people were killed by a quake in Yogyakarta in 2006, while 170,000 Indonesians perished in the Boxing Day tsunami of 2004.

The country has also suffered some of the world’s most notorious volcanic eruptions such as Tambora in 1815, and Krakatoa in 1883. The most powerful of all, though, struck Sumatra about 74,000 years ago, when the Toba eruption and the volcanic winter that followed wiped out 99 per cent of the human race. See A Disastrous History of the World.