The death toll in Iceland from Laki was just the tip of the iceberg. Iceland remains sparsely populated, so the death of a quarter of its population did not make Laki history’s deadliest eruption. Beyond Iceland, the eruption led to a decline in temperatures in the northern hemisphere – winter temperatures in the US, for example, dropped 10 degrees Fahrenheit in 1783, and remained below normal for several years afterwards. However, Laki’s deadliest impact was not in the US or North America, either. The deadly impact was in Europe and the northern hemisphere, to the southeast of Iceland.
The summer of 1783 had been a particularly hot one. A rare high pressure zone formed over Iceland that year; winds blew to the southeast. When Laki began spewing prodigious amounts of sulfuric dioxide into the sky, they were carried by the winds from Iceland. It created crop failures in Europe, draught in North Africa and India, and Japan’s worst famine. The eruption also caused an historic famine in Egypt, where a sixth of the population starved to death in 1784. It is estimated that the Laki eruption and its aftermath caused the deaths of an estimated six million people worldwide. This eruption making it the deadliest volcanic eruption in human history. It also illustrated low energy, large volume eruptions, can have a greater impact than single massive explosive eruptions. Especially if these eruptions occur over an extended period of time.
Where Did We Find This Stuff? Some Sources and Further Reading