|Eyjafjallajökull 17 April 2010.Credit : Iceland Meteo Office|
Iceland is one of the few places in the world where a mid-ocean ridge actually rises above sea level. Many volcanic eruptions along the ocean basin often go undetected because they can't be easily seen.
First settled by Vikings in the 9th century, Iceland is known as the land of fire and ice because of its volcanoes and glaciers. During the Middle Ages, Icelanders called the Hekla volcano, the country's most active, the "Gateway to Hell," believing that souls were dragged into the fire below.
Last year the Eyjafjallajokull eruption stoped almost all flights in Europe, and if i was Katla instead?
Iceland's "Angry Sister" hasn't even awoken yet. The three times in recorded history when Eyjafjallajökull has erupted, its neighbor, the much larger Katla, has followed suit.
Data do not yet suggest that a Katla eruption is imminent. Yet, in some respects, it is the far greater concern, both in Iceland and beyond.
Katla has erupted 16 times since 930, in 1755 exploding so violently that its ash settled on parts of Scotland. In 1918, Katla tore chunks of ice the size of houses from the Myrdalsjökull glacier atop it, sending them careening down its slopes and into the Atlantic on floods of melted glacier water.
Volcano Katla is located about half a kilometer below an Icelandic glacier called Myrdalsjokull. Scientists say that the large amount of ice atop the volcano is a recipe for ash clouds of greater magnitude than seen from the Icelandic volcano eruption that began last week.
Katla has been dormant for decades, but since the eruption of Eyjafjallajokull , it has seen a 200% increase in activity. Katla last erupted in tandem with Eyjafjallajokull in an 1821 blast, a pattern scientists say may recur now.
Katla last erupted on its own in 1921 and experts say that the volcano is presently overdue for another eruption. Katla is a much larger volcano, so any eruption there could be substantially more devastating than that of Eyjafjallajokull.
Many residents near the volcano are convinced that it will erupt soon, although they admittedly do not have scientific evidence to back their suppositions.
"When Katla went off in the 1700s, the USA suffered a very cold winter," says Gary Hufford, a scientist with the Alaska Region of the National Weather Service. "The Mississippi River froze just north of New Orleans, and the East Coast, especially New England, had an extremely cold winter. Depending on a new eruption, Katla could cause some serious weather changes."