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The good citizens of Iceland have two mega-problems this spring. One is their economic and banking situation, which is still in something close to meltdown mode. I cannot fathom finances and economics, so I’m in no position to really follow that part of the current and dreary Icelandic saga.
But the other is geological, and that’s a piece of the story a rock-head like me can better understand.
Since the days the Norse settled Iceland more than a thousand years ago, they have had to live with the fact that the Atlantic Ocean basin is slowly but steadily growing. And that matters because the growth is taking place due to volcanoes — including the ones creating their island nation. In short, Iceland is a high point of what geologists call the Mid-Atlantic ridge that is leading to the basin’s growth over time, both east and west via spreading at the ridge. Most of the ridge is underwater, but in Iceland it rises above the sea so people can live on it (if they are hardy enough, at least).
The whole Mid-Atlantic ridge is a series of volcanoes. Out of those outlets, molten rock pours on a regular basis. The molten material makes a solid, volcanic rock when it cools, both under the ocean waves and on the isle of Iceland. But, obviously, living with lava just down the block has some real challenges and drawbacks, even for the tough descendents of the Norse.
On the whole, folks in Iceland have coped well with their harsh environment. Naturally, from time immemorial, they have tried to keep their settlements away from obviously recent lava flows and the most active volcanic vents. And in modern times they have captured heat from hot water under the ground that they can to use as geothermal energy systems. That’s a good example, in my book, of making lemonade from lemons.
Currently, as you have seen in the news, they have another challenge besides lava to deal with. Because glaciers are not few and far between in Iceland, from time to time volcanic eruptions occur beside and even under them. And now has been such a time. That creates a special problem.
Lava, naturally enough, rapidly melts glacial ice. Liquefying a lot of ice quickly means that torrents of water flow downhill, so flooding results. Hundreds of Icelandic citizens in rural areas have been evacuated in front of flash flood threats over the past few weeks. Back in geologic time, it’s clear that massive outburst floods have occurred because of this effect.
Another threat from the volcanoes is that the floodwaters mix with soil and “ash” from the volcanic eruption. The ash is tiny bits of volcanic material. The problem is that this mixture flows downhill like a dense debris flow, taking out everything in its path. Geologists use the term “lahar” for the flows — a word you can look for in the news.
Yet another problem is one that makes more than Icelanders suffer. Volcanic ash is launched high into the atmosphere when volcanoes go through major eruptive cycles. In recent weeks Iceland’s ash output into the skies has been enough to affect both the good people of Iceland and their neighbors as far away as Poland. In particular, airplane routes have been diverted away from Iceland and many flights across the northern Atlantic and northern Europe have been cancelled due to volcanic ash in the air.
And the saga isn’t over. The eruptions have been coming from the Eyjafjallajokull volcano in southern Iceland. It is adjacent to the Katla volcano, a much bigger volcanic conduit — and one that could supply more lava all over again. In short, the story could get fiercely worse before it gets better. As I write these words, the situation is quieting down (thankfully) — but as you read this, the saga may have been launched into a new chapter. Geologists can make educated guesses about what will happen tomorrow, but not firm predictions about what will happen next month.
Between the collapse of the banks and assaults of Mother Nature, we can only wish Iceland’s residents the best.
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. E-mail her at rockdoc.wsu.edu, or follow her on the Web at www.rockdoc.wsu.edu and on Twitter @Rock
DocWSU. This column is a service of the College of Sciences at Washington State University.