IRISH HISTORICAL ANNALS TELL OF A PREVIOUSLY UNKNOWN LINK BETWEEN COLD WEATHER AND VOLCANIC ERUPTIONS

 

The survey of historical Irish annals has revealed an important clue on climate change and its link to volcanic activity. 

1500 years ago the weather in Ireland was bitterly cold.  Such historical record was confirmed by looking at ice cores that go back 40,000 years in time.  When compared the two give a mirror image of what happened in lower latitudes.

Volcano activity produced extremely cold weather spikes over a period of 1200 years, from AD 431 to 1649.  

During this period, 48 volcanic eruptions occurred that were visible from Greenland Ice cores collected by the Ice Sheet Project research in Greenland, as layers of ash, or volcanic sulfate, which mar the cores as darker deposits or bands.  

Of the 48 volcanic eruptions, 38 of them were directly correlated with extremely cold winters.  These events match with recorded historical events in Irish annals.  The winters were said to have been much more snowy and frosty, with ice covers on lakes and streams lasting much longer than usual.  

Since Ireland is considered a mild maritime weather country, these events would have caused a significant shift in the ability for the Irish to work and to grow crops.  

Such volcanic eruptions however, do not always bring colder seasons.  If the eruptions occurred in the summer, the trend would be toward colder weather, but if it occured in the winter at lower latitudes, or in the tropics, they would have caused warmer weather, since they push westerly winds that bring warmer ocean air toward Europe.  However, looking at the historical record, it also appears that low latitude eruptions may have caused extermely cold winters in Ireland. 

An example of this is the eruption of Peruvian giant Huaynaputina, which exploded forcefully in 1600, and which led to a very cold winter in Ireland for several years. 

Such anomaly then, renews calls for better understanding of the more subtle interplay between volcanic activity and climate, so that future events can be withstood with better preparations and planning. 

Source : Science Daily   6.6.13