The summer of the year 1783 was an amazing and portentous one, and full of horrible phaenomena; for besides the alarming meteors and tremendous thunder-storms that affrighted and distressed the different counties of this kingdom, the peculiar haze, or smokey fog, that prevailed for many weeks in this island, and in every part of Europe, and even beyond its limits, was a most extraordinary appearance, unlike anything known within the memory of man. By my journal I find that I had noticed this strange occurrence from June 23 to July 20 inclusive, during which period the wind varied to every quarter without making any alteration in the air. The sun, at noon, looked as blank as a clouded moon, and shed a rust- coloured ferruginous light on the ground, and floors of rooms; but was particularly lurid and blood-coloured at rising and setting. All the time the heat was so intense that butchers' meat could hardly be eaten on the day after it was killed; and the flies swarmed so in the lanes and hedges that they rendered the horses half frantic, and riding irksome. The country people began to look with a superstitious awe, at the red, louring aspect of the sun...While we're all fascinated by the current eruption of Eyjafjallajökull (great pictures!), spare a moment to contemplate Laki in 1783. 20% or more of Iceland's population died of famine, a cloud of poison gas hung about Iceland and Europe over a brutally hot summer, and the following winter was frigid across Europe and America. Puts all those delayed flights in perspective, doesn't it? If Eyjafjallajökull keeps belching, it'll be interesting to see if there are climatic effects, or at least good sunsets.
--Gilbert White, recalling the effects of the 1783 eruption of Laki on England
Of course, it might trigger Katla. Interesting Katla fact:
At the peak of the 1755 eruption the flood discharge has been estimated at 200,000–400,000 m³/s [that's cubic meters! --ed.]; for comparison, the combined average discharge of the Amazon, Mississippi, Nile, and Yangtze rivers is about 266,000 m³/s.Hat tip: Sailer.