Iceland: Learning to Understand Geology

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On our second day in Iceland, as we were driving toward the motel after a full and tiring day and most of the passengers on the bus were asleep, we passed through Reynisdrangar, a jumbled moonscape of strange formations rounded by a greenish fur of lichen and moss. At the moment I was too tired to ask our guide, Sigurdur, or Deedee, as he told us to call him, what they were, so I just stared at them. Earlier that day we climbed on the face of a cliff composed of geometrically shaped shafts of rock. The shapes were pentagons, perhaps hexagons rising like shards of crystals, with cracks separating the outer layers, which further emphasized their exact shapes. The shafts rose to unequal heights, making it easy to climb from one to another. People took turns climbing the shafts and posing on the flat tops. One girl (not in our group), a waifish teen, posed on the rocks like a young Stevie Nicks posing for an album cover, trying to hold a too-thin gown in place in the gusting beach wind. The beach itself was black sand and gravel, and people of all nationalities wandered up and down gazing at the geologic wonders around them. Out in the ocean three rock columns rise out of the ocean, and in the face of the cliff itself the waves have hollowed out shallow caves large enough to host the Mormon Tabernacle Choir.

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Earlier in the day we had stopped at a small museum at the foot of what once had been a glacier covering Eyjafjallajokull volcano, the one that in 2010 erupted and flooded the farm and land beneath it and set off an ash cloud that suspended air traffic in Europe for over a week. Then we had driven out to Dryholaey Peninsula, a massive cliff jutting out into the ocean a hundred meters above the water. The sea has eaten away the softer strata, turning the cliff into an arch, which gives the peninsula its name, doorhole. That night, just before the appearance of the aurora borealis, which brought squeals of excitement from members of our group, we spotted on the horizon the dim orange glow of an active volcano over 60 miles away. Combined with the geothermal power plant and standing between two continents that we experienced the first day, Iceland has been a crash course in geology and physical science.

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Today, Sigurdur, our guide, explains that the surreal landscape is a lava flow, probably 300 years or so old, and that lichen and moss are the first things that will grow on lava, the first step in reclaiming the soil for other plants. The columns rising out of the ocean and the geometric shafts composing the cliff face are basalt, a hard, volcanic mineral that rises from deep inside the earth in shafts. They alone remain as the weaker minerals of the earth around them succumb to the forces of ocean, wind, and cold.

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The problem with thinking about geology and geologic time is that it is hard, for me anyway, to imagine the world looking significantly differently than it does today. Erosion and entropic forces make sense to me. I can observe them. I understand the force of water washing away soil and wearing away rock. Freezing water expands and breaks rocks apart. Water combines with minerals in the soil to create an acid that builds caves. I’ve read enough to understand the theory: John McPhee’s Basin and Range explains in great detail the forces that shaped the Great Basin of Wyoming, Utah, Nevada, and Colorado, Four Corners explains how tectonic plates bumped with enough force to cause the uplift that raised the Colorado Plateau a thousand feet above the surrounding land, and I’ve hiked the Colorado Front Range with a geologist who is good at explaining how similar forces wrinkled the Hogbacks like the pleats of an accordion. While the theory makes sense, it takes an imaginative and curious person to take a landscape not at face value, but instead imagine how it got to be the way it is. For me, looking at a wide valley and imagining it being carved by a river of ice is as difficult as Icelandic pronunciation.

Iceland, where geologic forces are happening on a daily basis, can change all of that. Today we drove east for over an hour along the southern coast of Iceland. The whole time we drove we could see a small arm of Vatnajokull, Iceland’s largest glacier, which looked like a mountain of ice. In truth, what we could see was a tiny portion of the whole, like an explorer finding the tip of the Florida peninsula, then sailing north looking for the end of what he had found. As we approach the object of our drive, a glacial lagoon filled with floating icebergs calved off of the end of the glacier that are slowly floating out the outlet to the sea, we cross miles of flood plain veined with riverbeds draining the glacier into the sea. After a boat trip through the lagoon, we drive to the foot of an outlet glacier and climb the ledges above it to get a look at an active glacier. Bearing in mind that an outlet glacier is a pressure relief valve, a pinprick leak in a pipe, rather than the main line that is the glacier, the outlet is impressive.

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Glaciers are formed from falling snow that remains frozen over thousands of years, slowly compacting under the accumulated weight and pressure, into incredibly dense packs of ice. Once the ice reaches a depth of over 40 meters, or over 120 feet, the weight forces the ice to flow, downhill; like any body of water it wants to reach the sea. Under that incredible weight, despite the fact that it only flows a few feet each year, the ice has the power to chew rock and earth, carving out a swath of land like a backhoe blade scooping out a drainage ditch. As they move the glaciers push up dirt and rock in front of it like a bulldozer pushing up a pile of earth, which it deposits at the end of the mountains, where its bulk is dispersed through a calving process, leaving behind high dunes of rock and gravel and dirt called a moraine.

On the drive back we go once more over the flood plain, where Sigurdur tells us about an earlier volcanic eruption which melted a large chunk of glacier and caused a massive flood that scoured the flood plain we have driven twice clean and flat. We stop at a monument that looks like a piece of abstract art, but in reality is the twisted girders of the steel bridge wiped out by the flood that followed the eruption. The students in the van get out slowly, tired from the earlier hikes, cold with the wind blowing heavy, hungry with supper waiting a few miles ahead. They mill around the educational signs and glance at the girders long enough to satisfy the guide, then head back to the van. Sigurdur explains to me the timeline of the volcano eruption, then points to the horizon to impress on me how wide the flood waters, water that came from thousands of years of snowfall released almost instantaneously, and gets the sought after response. I understand the vast forces at work, and I am impressed.

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