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Archive for the ‘Summit Station’ Category

What’s cooler: snow pits or soil pits? Among the IGERT group, that could be a bit of a loaded question. I may be just a tad biased, so I will diplomatically bow out of answering that question directly, and instead present the facts that I’ve gathered about snow and soil and what we can learn from them.

Creating the pit

Digging is digging is digging. If you want a hole in the ground, you’ve found the right group! We love it so much that we have even created a dance move to celebrate digging.

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Whether in the tundra or on the ice, the IGERT crew can conquer any digging challenge.

Layers and Horizons

One feature shared between both soils and snow is their tendency to form stratigraphic layers. In snow, these layers can be seasonal or from particular storm events. As more snow accumulates every year, and the layers remain frozen even through the summer, the layers continuously build on top of one another. In soils, the layers are referred to as “horizons.”   The uppermost horizon is known as the O-horizon, which is an organic rich layer, followed by the A, B and C horizons. Proceeding downwards, the horizons become decreasingly organic and increasingly mineral rich until you reach the parent material beneath the soil.

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Stratigraphy in the snow and firn at Summit (left) and in the Sandflugtdalen of Kangerlussuaq (right).

Dating

In both soil and snow pits, isotopes can be used to estimate the age of the horizon. In high snow accumulation areas, the snow layers show seasonal trends in oxygen isotopes. Counting back from the surface allows researchers to determine the age of layers. In soils, any remaining organic material in the soils can be dated by analyzing the isotopes of carbon. Histories can be unraveled in both snow and soil by tying the age of the horizons to other properties. In soils, this could be an investigation of what types of plants were growing at a time in the past. In snow, this could be a study of how carbon dioxide in the atmosphere has changed over time. In either case, the story needs a timeline and isotopes provide the tick marks for us.

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Though I was skeptical at first, Ross’s module on soil horizons won me over!

Density

In seems that across many disciplines, density measurements are used as a simple way to characterize a material. We found ourselves measuring density along snow pit walls at Summit and in deflation zone scarps in Kangerlussuaq.  Not surprisingly, the least dense loess sample in our soil studies was far denser than even the ice samples that we measured at Summit.

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Ruth and Kristin measure snow density at Summit (left), and Zak measures loess density in a deflation zone scarp (right).

Little known perks

We’ve also managed to explore some of the lesser known perks of soil and snow pits. We have found that covered snow pits create a perfect venue for puppet shows. And though it’s a bit of an acquired taste, Zak has found sandy soils to be quite a delicacy!

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Zak tests the grit of the soil against his teeth.

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While up at Summit camp, we were fortunate to overlap with students from the Joint Science Education Project (JSEP). The program provides high school students from Denmark, Greenland and the United States with the opportunity to travel to Summit Station and learn about the scientific research that occurs there. The ladies of Cohort 4 were eager to share our polar knowledge with the JSEP students, so we set up four different activities that revolved around snow and ice.

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Summit flies flags from all of the participating countries in the Joint Science Education Project.

The first activity took the students out around camp to investigate snow albedo. We searched for snow that somehow looked different. For example, these differences could be due to compaction from heavy equipment, exhaust from LC-130 planes, or frost flower growth on the surface. We made measurements of albedo and used hand lenses to take a closer look at the snow grains and see how they differed from place to place.

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Looking at snow grains through a hand lens.

One afternoon took us down to the beautiful backlit snow pit, where we discussed snow layering from different storm events and different seasons. We analyzed the snow stratigraphy, made density measurements and talked about implications for ice core studies, like the research done on GISP2 right at Summit!

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Measuring density in the backlit snow pit.

Kristin led a hands-on exercise to teach the JSEP participants about glacial flow. The students made their own flubber from glue, water and borax, and they ran experiments to determine how their flubber “glaciers” would flow under various “bedrock” conditions. A wee bit messy, but worth the clean up!

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Kristin explains the physics of glacial flow using flubber!

Our last afternoon at Summit fell on a beautiful, warm, sunny-sky day. The JSEP students broke into teams and set out on a scavenger hunt! Using GPS coordinates or clues about things around camp, the students were led place to place until they reached a final clue that could only be solved with input from all three groups. At last, they found the long sought-after buried treasure of Summit Camp!

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The buried treasure of Summit Camp is found!

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Coveted penguin stickers in the scavenger hunt prize!

When we weren’t sharing our love of science, the IGERT and JSEP teams enjoyed other activities around camp, such as singing songs together in the Big House or playing board games in the Recport. It was a fantastic opportunity for the IGERT students to share our science, to learn about science education in other countries, and to have a great time while doing it!

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JSEP and IGERT groups after a successful scavenger hunt!

Learn more about the JSEP program at their website: http://www.polartrec.com/expeditions/joint-science-education-project-2013

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The Greenland Ice Sheet holds many stories of past climate. Summit Camp, in fact, was established for scientists to drill two miles down into the ice and pull out an ice core that tells a story of warming and cooling events from the past 100,000 years.

Ten years and 1 week after the completion of this GISP2 drilling operation, the IGERT C4 gals made our way up to Summit and uncovered a new story held in recent ice.

Alden, Kristin, Christine, and Ruth at the site of GISP2

Alden, Kristin, Christine, and Ruth at the site of GISP2

In July of last year, as you may recall, 97% of the Greenland icesheet experienced surface melting.

While much of this melt refroze on the surface,  some melted snow flowed below the surface to form frozen fingers poking down through layers of previously fallen snow. The frozen fingers, which we call vertical flow channels, are like icicles that are suspended in snow rather than air.

A trip to a backlit snowpit introduced us to the melt layer and one vertical flow channel. These features were buried 75 cm below the surface by a year’s worth of snow.

Unlike surrounding layers, the melt layer and the vertical flow channels were icy, clear, and hard; easily distinguishable with the naked eye or the touch of a finger running down the snow pit wall. It is important for scientists to study these icy features to better understand the physics of water flow through snow and to understand how their  properties may affect the information that satellites and radar collect about the ice sheet.

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Alden showing us the snow pit. The green arrow points to the melt layer, the white arrow points to a vertical flow channel (i.e., finger).

Our mission was to dig under the frozen melt layer and excavate any ice fingers we could find.  We were like archeologists, hoping to discover arctic artifacts.

We first uncovered the snow pit that Alden had dug earlier in the season.

Removing the snow from plywood that covers the snow pit.

Removing the snow from plywood that covers the snow pit.

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Revealing the snow pit.

Then Alden and Kristin graphed the stratigraphy of the snow pit layers to document the depths of the melt layer, winter and summer snow, and wind crusts.

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Kristin’s lovely stratigraphy diagram

With our hands protected by waterproof mittens and zipbloc bags, we swept away the snow under the melt layer, feeling for any icy vertical flow channels. Kristin and I found several frozen fingers right away and started excavating by delicately brushing out the snow around them until we reached their icy bottom tips.  It took me 2 hours to excavate a beautiful flow channel that was one-half meter long.  We measured the fingers, recorded their position, and made notes about their form.

Carefully excavating a finger, which I nicknamed ‘Precious’.

Alden and Ruth worked on a side of a snow pit that seemed to have a different flow pattern. They diligently dug back through 1 meter of snow but didn’t uncover any frozen fingers.

While Kristin and I chip away at our excavations, Ruth and Alden continue to dig back, looking for vertical flow columns...the snow pit is getting larger!

While Kristin and I chip away at our excavations, Ruth and Alden continue to dig back, looking for vertical flow channels…the snow pit is getting larger!

As we reached the corner of our site, Mary found a behemoth vertical flow channel. We named him Hector II. Tired and cold, Ruth and Alden quickly sawed, shoveled, and pried Hector II out of the snow so that we could return back to camp.

After dinner, Mary, Ruth, and I excavated Hector II ex-situ and loaded him and our other frozen fingers into an insulated ice core box. We covered the fingers with cardboard, snow, and icepacks to make sure that they would stay frozen on their trip back to Dartmouth College.

Ruth carrying Hector II - all wrapped up - to the ice core box.

Ruth carrying Hector II – all wrapped up – to the ice core box.

We made one last trip to the snow pit…this time on a snow mobile. I was particularly excited about this arrangement. We blazed across the ice sheet at a whopping 5 miles per hour, filled in our digging site, and recovered our tools.  Although the work was difficult, we were grateful to be at Summit a year after the surface melt, when the ice fingers were still within reach of a shovel and the hands of four motivated IGERTs.

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Celebrating a job well done

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After a 2 hour C-130 flight from Kangerlussuaq, the ladies of C4 have arrived at Summit! We were greeted by the incredibly hospitable staff of scientists working at the base… and some windy and cold weather conditions.

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Panoramic view inside the LC-130 flight- Cargo on one end, passengers on the other.

Summit Station is a research station located on the summit of the Greenland Ice Sheet (~10,500 ft) and was built in 1989 to support the GISP2 (Greenland Ice Sheet Project Two) ice core drilling project. The station consists of the “Big House”, a big blue building on stilts, the “Greenhouse”, a living facility for the more permanent scientists, “tent city” for all of us passing through and those preferring a crisper sleeping environment, and a few other science support and instrument buildings.

The ladies of C4 with Mary outside the Big House

The ladies of C4 with Mary outside the Big House

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helping transport “freshies” (fresh food) to the Big House kitchen after a shipment arrived

Some of the delicious Summit food: Halibut, seasoned rice and some fruit salad

Some of the delicious Summit food: Halibut, seasoned rice, cabbage and chickpea salad and some fruit salad

The first thing we did upon arrival at Summit was to help bring all the “freshies” (fresh produce) into the Big House that came with us on our flight. Summit has a reputation of having fantastic food– this year was absolutely no exception. Kathy (our very talented cook) created some incredible meals… hopefully we’ll be able to replicate some of her recipes later on in the field!

Since Summit Station is at ~10,500 feet and we had just come from sea level, most of the first day was spent trying to limit our physical activity and acclimatize to the lower levels of oxygen.  Clearly hiking and digging snow pits were out of the question, so we did the next best thing- volunteered as “house mouse” for the day! It’s a job that rotates around camp and the person (or people in our case) help clean dishes, wipe down tables and tidy up the Big House.

The ladies of C4 helping with "house mouse" duties

The ladies of C4 helping with “house mouse” duties

After helping clean up the Big House and moving food into the kitchen, it was now time to move into our living quarters for the next few days… Welcome to “tent city”, an arrangement of 16 or so tents in the middle of the living areas. Each tent was an Arctic Oven tent and was furnished with a cot and at least 2 sleeping pads on top of that. Usually, when not at maximum capacity, everyone gets their own tent- all of us living in “tent city” were among the lucky ones to have a whole tent to ourselves.

Me (Kristin) standing outside my humble abode for the week- a tent in "tent city!"

Me (Kristin) standing outside my humble abode for the week- a tent in “tent city”

During working hours (which are quite variable here given that presently the sun does not set), everyone is out and about either working on their science or working to keep the base up and running. There are generally less than 20 people that reside at Summit Station during the summer and are needed to keep it running- but the station can hold over 55 people. The maximum number of people at Summit during our stay was also the maximum number of people at the station this summer- we topped out at 46 people!

Launching a weather balloon for the ICECAPS project

Launching a weather balloon for the ICECAPS project

The control/data collection center for the 40 m tall weather station (this lives about 20 m under the ice)

After everyone has put in a long day of science and Summit work has been done, we’re able to relax a little bit after dinner before bed. So far some of our favorite activities have been playing some group board games or sitting in the Big House and playing some music!

One of the relaxing evening musical sessions from "The Alden Band"! Members include: Alden (vocals/scientist), Dave (piano, guitar/ scientist), Max (drums/ scientist, not pictured) and Tyler (band manager/ medic, not pictured)

One of the relaxing evening musical sessions from “The Alden Band”! Members include: Alden (vocals/scientist), Dave (piano, guitar/ scientist), Max (drums/ scientist, not pictured) and Tyler (band manager/ medic, not pictured)

Stay tuned for more science updates from Summit- but so far it has been fantastic being up here at the highest point in Greenland!

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When you walk outside at Summit Station without your sunglasses, all you see is blinding white in all directions.  Snow reflects so much sunlight that sunglasses and copious amounts of sunscreen are necessities at all times.  The scientific term for reflectivity is albedo, or the fraction of incoming light that a surface bounces back.  The albedo around Summit Station is pretty close to one; almost 100% of the incoming light bounces back (towards our vulnerable eyes and skin!).

Alden in front of the great white expanse of the Greenland Ice Sheet.

Alden in front of the great white expanse of the Greenland Ice Sheet.

But ‘pretty close to one’ isn’t good enough for IGERT fellow Alden Adolph, who studies albedo in New Hampshire and, for the past month, at Summit Station.  During the month of June, Alden made albedo measurements every day at one location, to see how albedo changed over the course of the month, and to relate albedo to other variables like grain size and snow density.

While the IGERTs were at Summit, Alden took advantage of the extra hands to address a question she’s been contemplating: how does albedo vary spatially?  If she takes multiple measurements at just one location, is she capturing the whole picture?  Or if she moves a few meters away, would the measurement be entirely different?

To answer this question, we set out with our handy field spectrometer, a long tape measure, and a few flags.  We marked out a 50-meter by 50-meter grid on fresh, undisturbed snow.

Setting up our albedo grid

Setting up our albedo grid

Alden, our trusty instructor, showed us how to use the instrument.

Learning how to use the field spectrometer.

Learning how to use the field spectrometer.

Since albedo is the ratio of reflected to incoming light, each measurement has two parts: first we point the sensor toward the sun, then we point the sensor toward the ground.  The sensor is attached to a long metal bar that needs to be level to the ground.

The field spectrometer in action!

The field spectrometer in action!

In the field, a measurement sounds something like this:

“Level up.”

“Ding!” (The computer makes a very satisfying sound when it has completed a measurement.)

“Level down.”

“Ding!”

Repeat two more times, move 10 meters along the transect, and repeat.  At the end of our grid, we had completed more than a hundred measurements that are currently waiting for Alden to process.  Although the surface all looks bright to our eyes, the field spectrometer will do a much better job at distinguishing small variation in the albedo at Summit.

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After three fantastic weeks at Summit, our group of four (IGERTeer Ben Walker, Allison, Jim and I) will return to the US tomorrow. Our last week was very productive and full of radar surveys! Thanks to our colleagues at the Center for Remote Sensing of Ice Sheets (CReSIS), we have a spectacular, cutting-edge radar system that we are using to look at ice layers in the snow. We pull the radar across the snow using a snowmobile so that we can cover lots of ground at a set speed. We had hoped that our friend the Cool Robot would be able to tow the radar, but weighing in at over 400 pounds, the CReSIS radar system proved to be too great an adversary, and the Cool Robot could not quite make the cut on the softer snow.

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Might look like a smurf, but that’s me running a radar survey with the CReSIS Snow Radar. (Photo: Allison Morlock)

The Cool Robot was able to do a special radar survey for the camp by taking a look at an old freezer trench (where food and ice cores were once stored) that had been buried several years ago. The robot drove over the freezer trench pulling the smaller radar system to see if any cavities remained where the freezer once was. Check out the glamor shot below of the Cool Robot with the Summit “Big House” in the background.

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Cool Robot running a radar survey of Summit’s old freezer trench. (Photo: Tom)

In our journey homeward, we had the great fortune of catching up with Ruth, Christine, Jess and Zach in Kangerlussuaq for dinner. We enjoyed some food from the local “Polar Bear Inn” and swapped stories about our trips –ours coming to an end and theirs just beginning. The Kanger crew headed back to their camp to get ready for another big day of science on the tundra tomorrow. Our agenda for tomorrow includes a flight back to Scotia with the Air National Guard. Once I’m back in Hanover, I’ll be pulling together the data I gathered during our trip to make plans for our next visit to Summit in mid-July.

I can’t thank the Summit Station crew enough for all that they did to make our visit go so smoothly. Though a few days late at this point, the sentiments are still there–wishing everyone a happy solstice and the best of luck for the rest of the field season. Greenland, I’ll be back soon!

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The crew at Summit wishing a happy solstice to all! (Photo: Katie Hess)

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To see a world in a grain of sand,

and a heaven in a wild flower,

Hold infinity in the palm of your hand,

And eternity in an hour.

– William Blake, excerpt from “Auguries of Innocence”

While at Summit, we keep ourselves very busy trying to accomplish science goals – making measurements, collecting samples, running tests and troubleshooting robot performance. It’s hectic and fun and exhilarating, and it all moves so quickly. Every day, right after eating a delicious lunch and filling up on perfectly scrumptious cookies, I tow my sled of instruments down to the south end of the station. With the last building out of view, I unpack my gear and set out to make a long series of measurements. Before I get started, I remind myself to take a look out over the seemingly infinite expanse of ice and let it sink in. I have the incredible opportunity to be in such a special place doing exactly what I want to be doing.  The beauty and calm of the place can be experienced by immersing yourself in the surroundings, or just by taking a look down at the delicate snowflakes that coat the vast ice surface.

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Fresh dendrite snow flakes from the morning of June 14th, as seen through a microscope. (Photo: Elena Willmot)

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