The Year Without A Summer

In 1815 Mount Tambora, located in Indonesia, exploded in history’s most calamitous volcanic eruption.  More than 70,000 people were killed.  The summit of the mountain was reduced from 4,300 meters to less than 2,900 meters.  The explosive yield of this eruption has been estimated at about 800 megatons.  This was a nasty neighbor.  The larger effects would not be felt for a while, though.

Tambora was to have a lasting impact on the global climate, but it did have some help.  In 1812 La Soufriere in the Caribbean erupted, as did Mayon in the Philippines in 1814; those two volcanoes had already put a significant amount of ash into the atmosphere.  Additionally, the Sun was in a period of lower activity, so the stage was set for Tambora’s dramatic entrance.  When Tambora’s 800 megaton blast occurred, more than ninety cubic miles of volcanic ash was blasted into the atmosphere.  That tremendous load of ash coupled with the ash already present in the atmosphere from the two previous eruptions, as well as the sun’s lower activity resulted in 1816 being called the Year Without a Summer.

Unusually late frost hit New England and Eastern Canada in the spring of 1816 virtually wiping out the crops that were already in the ground, and the following month two huge snowstorms killed many people.  This snow also killed the crops that had survived the earlier frost, leading to famine; people, their vitality sapped by hunger and malnutrition, began to die from disease.  So little rain fell in July and August, drought damage stunted the crops that had managed to hold on.  Reduced sunlight prevented crops from growing and maturing, even if they could survive the cold and drought.

Other parts of the world fared no better.  England experienced greatly increased rain, and reduced temperatures; this resulted in crop failures.  Many parts of mainland Europe experienced crop failures.  Because of the Napoleonic wars, Europe was already having problems with shortages of food; the crop failures exacerbated this problem.  Riots and looting ensued, as did famine.  There was extensive flooding of numerous rivers because of increased rainfall.  About 200,000 people died as the result of famine and disease.  Asia had unusually low temperatures (including frost), and heavy monsoons.  Rice production was drastically reduced, and famine and disease were widespread.

That was quite a party Tabora threw.  It is just a good thing it doesn’t go to that much trouble very often.  There have been worse eruptions, though.  I will talk about just one more next time.