Could Iceland eruption trigger climate scale blast?

Scientists are watching to see if a second much larger eruption may be triggered by the current eruption near Iceland's Eyjafjallajokull glacier.

Climate scientists' eyes perk up every time there's a volcanic eruption. This one has some eyes wide open.

An eruption last weekend near Iceland's Eyjafjallajokull glacier does not appear to be big enough to create cause for concern. But history has shown that eruption in this area have triggered larger climate scale eruptions in the past.

The eruption at Eyjafjallajokull has raised concerns that the nearby Katla volcano may blow.

You can read the entire AP story here. Below are a few choice excerpts from the AP account.

"Scientists say history has proven that when the Eyjafjallajokull volcano erupts, Katla follows - the only question is how soon. And Katla, located under the massive Myrdalsjokull icecap, threatens disastrous flooding and explosive blasts when it blows.

Like earthquakes, predicting the timing of volcanic eruptions is an imprecise science. An eruption at the Katla volcano could be disastrous, however - both for Iceland and other nations.

Iceland's Laki volcano erupted in 1783, freeing gases that turned into smog. The smog floated across the Jet Stream, changing weather patterns. Many died from gas poisoning in the British Isles. Crop production fell in western Europe. Famine spread. Some even linked the eruption, which helped fuel famine, to the French Revolution. Painters in the 18th century illustrated fiery sunsets in their works.

The winter of 1784 was also one of the longest and coldest on record in North America. New England reported a record stretch of below-zero temperatures and New Jersey reported record snow accumulation. The Mississippi River also reportedly froze in New Orleans.

"These are Hollywood-sort of scenarios but possible," said Colin Macpherson, a geologist with the University of Durham. "As the melt rises, it's a little like taking a cork out of a champagne bottle.""

The fear is that a major eruption could send volcanic gasses like sulfer dioxide high into the atmosphere. These tiny particles can spread around the globe and stay elevated for years. They are extremely efficient at reflecting incoming sunlight before it can reach the earth's surface to warm the planet. The result is net cooling of the earth's surface. Though the cooling is usually temporary, it can last several years if the eruption is large enough.

Major climatic scale volcanic eruptions are rare, but they do occur. In 1815 a massive eruption of Indonesia's Mt. Tambora put so much debris into the stratosphere that it is believed to have created the "Year without a summer" in New England in 1816. There was frost in every month of summer that year causing massive crop failures in New England.

Mt. Pinatubo's eruption in 1992 also triggered large scale cooling in the following years.

Mt. Pinatubo erupts in the Philippines in 1992. (USGS photo)

Volcanologists and climate scientists will be keeping a close eye on Iceland in the coming weeks.

PH