The Clash had one of their most famous songs in 1981, “Should I Stay or Should I Go.” If you were of the right age (and I was), you couldn’t escape it. It’s been covered by everybody from Tom Petty and the Heartbreakers to British Prime Minister Tony Blair (it was a digital mix; he didn’t actually sing it). It’s been used in commercials for Levi’s and Pontiac. For me, it’s come to represent the tough do/don’t, stop/go, up/down, yes/no, black/white, now/later, here/there decisions I make (almost) daily. For Iceland’s Katla volcano, it seems to represent the classic geological conundrum: Should I rumble and sizzle a bit, or should I unleash a fury that hasn’t been seen in almost 100 years.
Presently, “Should I Blow?” might be answered with a resounding “Yes!” in the near future. Although volcanologists and seismologists can trace the current period of Katla unrest to 1999 and even a couple of times over the past year tremors and earthquakes have spurred concern of an imminent eruption, the current level of unrest is quite high. In fact, after a long period of magnitude-three tremors, a magnitude-four quake was detected last week. “It is definitely showing signs of restlessness,” said Mr. Pall Einarsson, a professor of geophysics at the University of Iceland.
The fear, of course, is that when Katla blows, experts suspect it will be catastrophic. Its last major eruption lasted for weeks, darkened the skies for months, killed off crops and livestock and icebergs the size of houses were seen floating out to sea. And because Katla sits under a layer of glacial ice, the meltwater of that eruption took on the appearance of the Amazon River and flooded surrounding farmlands. In the big picture geologically, Katla makes Eyjafjallajökull look like a “small” volcano — and the April, 2010 Eyjafjallajökull eruption is responsible for shutting down North Atlantic and European air traffic for weeks.
This sub-glacial volcano is the largest volcano in Iceland and sits upon a magma chamber much larger than Eyjafjallajökull’s. It’s located on the northern tip of the Mid-Atlantic Ridge near the southern coast of Iceland. The eruption, when it occurs, will be explosive — critically enhanced by the expanding steam resulting from magma contacting the glacial icecap.
Historically, Eyjafjallajökull eruptions have preceded Katla eruptions and though geologists expected last year’s Eyjafjallajökull eruption to trigger a larger and more powerful Katla eruption, it never occurred. Additionally, records show that Katla has a major eruption approximately every 100 years — the last major, icecap-breaking eruption occurred 93 years ago. At the most, it’s overdue for a major eruption. At the least, it’s plain due.
Presently, civil defense officials have been holding regular meetings with geologists and other scientists. Disaster officials have also drafted an evacuation plan and have allocated temporary housing for several nearby towns, including the village of Vik, just 12 miles to the south. Experts fear residents will have less than an hour to evacuate once the volcano erupts.
YourWeatherBlog has written pieces about Katla before. You can check them out here and here. We’ve also written quite a bit on a few of Katla’s neighbors including Hekla, Bárðarbunga, Grímsvötn and of course Eyjafjallajökull on several occasions.