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Percussion in Greenland

Posted August 12th, 2009 by
Julia working on a core

Julia working on a core

For the first time since we arrived, there is a steady bank of clouds advancing from the southeast. The low fog creates the intriguing illusion of topography on the horizon, as if we were out at sea but approaching land or on the salty plains of a wide basin and range playa. It is still clear and sunny here, with just a few high clouds drifting here and there, but we shall see what the weather has in store!

Even if conditions do go south, it won’t affect our daily operations much. The geodesic dome in which we spend most of our leisure time is built of steel and wood, with ample insulation and heat. The science trench is so deep in the snow—which is an excellent insulator—that its temperature remains relatively constant. Despite daily surface temperature swings of over 30 degrees, the trench is only about 3 degrees cooler when we arrive in the morning than it was the afternoon before. The worst part about bad weather would indisputably be the walk to the toilets, which are plywood seats set in small white tents on the outskirts of camp. Although visiting the bathrooms is unavoidable, it is often difficult to muster up the motivation to make the trek in the heart of the 0 degree night, or in the howling arctic wind.

In addition, we have recently discovered a popular new indoor activity. Last night, we held the first meeting of the NEEM Jug (and-other-creative-noise-making-apparatus) Band. I brought my banjo to the ice, assuming among my 33 colleagues, there would be other musicians. I was right, however none of them brought their instruments. Nevertheless, when I started picking, some were overcome by the urge to join in. Soon, we had an unlikely ensemble of percussion instruments, including but not limited to: a typewriter, a fennel seed shaker, a coffee can and wooden spoon washboard, and a triangle meets jazz brush imitation formed by the interaction of a metal spatula and a sieve. Inspired by our first “practice”, several of the drillers started working on a bucket bass made of an old drill fluid barrel this morning. We will make our debut at the Sunday brunch, an up-north down-home version of the jazz brunch.

In the good weather we’ve had so far, there has been a good deal of outdoor recreation as well. Until a few days ago, this mainly consisted of running, skiing, or walking up and down the groomed runway. Although this provided an ideal, packed surface for these kinds of activities, the scenery was a bit dull. In particular, I was not a fan of the black and red flags that tick off every 100 m of the 9 km lap. Sharing my sentiment, Tim, our intrepid handyman, forged a new “mountain track.” It weaves though the valleys of the NEEM Mountains—heaps of snow upon which overwintering camp materials are stacked to avoid being buried during the following accumulation season. Although there is no relief in the trail to speak of, it is quite scenic. From the far point, if you squat down, it is possible to almost not see camp! And in the golden-hued hour of the solar minimum (it is still far too bright to be called a sunset), the mountain track turns into the NEEM Riviera. Out for a stroll
this evening, I ran into runners, skiers, and a couple gazing out onto the ice sheet from the plywood “couch” that has been placed out in the hills.

In between all this recreation, we have been making good progress drilling and processing the ice core. The drillers have passed the 1600 m mark, far in excess of the goal for the season. In the science trench, we have mostly kept pace with the drillers. During the last week, we moved from the Younger Dryas, the cold period immediately preceding the Holocene, through the Bolling-Allerod (the warm period before that), and into the Last Glacial Maximum. The result is that, at the moment, my job is a bit boring. The electrical conductivity of glacial ice is essentially zilch, meaning that my scans produce nearly flat profiles for every core, and will continue to do so for the foreseeable future. However, small annual fluctuations are visible, and the compiled ECM record for all the NEEM ice processed so far compares well with the profile from North GRIP, the previous deep ice core drilled in Greenland.

This is encouraging, because it suggests, at least to first order, that these different locations experienced similar atmospheric conditions throughout the last deglaciation. In the next year, as we analyze the ice we have recovered, we will see how climatically similar the NEEM record is to NGRIP. Based on the strong similarities between previously drilled Greenland ice cores, we expect NEEM to show the same patterns of climate during the last glacial period. This is why we take Greenland ice cores to represent the regional climate of the North Atlantic. The most exciting part about NEEM will be the record we obtain from the last interglacial period, 125 thousand years ago. As of now, we have no northern hemisphere ice core record from this period, which may have been more similar to the present than any time during the glacial. Drilling that ice, and then measuring it, is a long way off, but it is exciting to think that the mysterious Eemian ice is sitting at the bottom of our ever-deepening drill hole, containing geochemical signlas that have never been measured.

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