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.