As European airlines begin to recover from their ash-induced grounding, attention is turning to Iceland's history of volcanic activity. The volcano responsible for the current plume of ash, Eyjafjallajokull, historically has erupted in tandem with neighboring Katla — which could produce more devastating effects. In the early 1700s, a major outburst from Katla led to a temporary blockage of sunlight, causing temperatures to plummet and the mouth of the Mississippi River to freeze north of New Orleans, Louisiana. Another volcano, Laki (which is not likely to be awoken by Eyjafjallajokull's rumblings) produced toxic gases and climatological follow-on effects so severe in 1783 that European agriculture and social conditions ultimately were affected.
