The Juneau Icefield: Sub-Surface Exploration

Kit Cunningham, Montana State University
Annie Zaccarin, University of California, San Diego

As the sun warmed the rocks and the clouds drifted away from Camp 18, the biogeochemistry research group skied up and away from camp. The weather was pleasant. A glacial breeze cooled us as we gleefully kicked and glided our way across the icefield towards the Matthes-Llewellyn divide. The divide is a topographic high between the two glaciers, from which point the ice flows downhill and away in both directions. Our research group aimed to gather snow samples from the past years’ snowpack on the Llewellyn Glacier to analyze in a lab.

We arrived at our location, roughly halfway between the two sides of the Llewellyn Glacier, on a relatively flat area downhill of the divide. Enthusiastic to start working, we kicked off our skis and set up our work area amid the ever glorious snow and mountain peaks surrounding us. The first step was to dig a trench roughly 1.5 m by 3 m, and 1 m deep. We used the excavated snow to build a shade wall on the south side of the work area, protecting sensitive samples from the sun. This trench and wall created our main workstation, a sort of subterranean workbench where we could comfortably stand and use the top of the snowpack as a waist-high counter top. After this our team prepared to gather snow samples by pulling up snow cores from the depths of the snow beneath our feet, just to the side of the trench. We all picked a job to start at on our snow core assembly line and enthusiastically got ready for a day of collecting samples.

The snow core assembly starts with gathering the snow core itself. This consisted of 3 main parts: the snow corer, the flights, and the handle. The snow corer is a tube about 1.5 m long, with plastic threads down the outside connecting to sharp teeth, and metal latches in the inside, also known as ‘dogs’ (Fig. 1). The snow corer acts like a hollow screw, with the plastic threads on the side helping to guide it straight downward as the sharp teeth cut into the snow. The metal latches are at the inside bottom of the tube, which prevent the snow core from sliding out when the snow core is brought to the surface.
 

Figure 1. Image of the bottom of a snow corer. Photo Credit: Kovacs Enterprise; Ice Drilling and Core Equipment

Figure 1. Image of the bottom of a snow corer. Photo Credit: Kovacs Enterprise; Ice Drilling and Core Equipment

A flight, the second section of the set up, is a meter-long attachment to the handle. It is meant to increase the depth of the coring hole. Basically, once the snow corer is deeper than its own height (1.5 m), we need additional attachments in able to retrieve it. A flight is one meter long, so if the snow core hole is 10 m deep, we need to attach 10 flights to the handle to drill and recover the core. The last piece of the snow corer set up is the handle. This is where all the power comes from, with our own arm strength. We operate the drill by turning the T-shaped handle, slowly spinning the whole apparatus and drilling the corer deep into the snow.

Caption: Kit Cunningham and Chris Miele adding flights to the drill (partly lowered in the hole). Photo credit: Sarah Fortner

Caption: Kit Cunningham and Chris Miele adding flights to the drill (partly lowered in the hole). Photo credit: Sarah Fortner

Once the snow corer is set up, we began the core extraction. I started out at the beginning of the assembly line, pulling the snow core out of the hole; which in my opinion is the most fun job. Using the snow core assembly, I pulled out our first segment of snow and slid it out of the snow corer and onto our workbench. Since extra snow shavings, or filings, from the threads of the snow corer can gather on top of the snow core sample itself, we measured both the depth of the hole and the length of the snow core and compared the measurements. If the snow core sample was longer than the depth of the hole, we removed the excess snow (filings from the side and top of the hole). As the snow core assembly went deeper, more filings got into the core, and this discrepancy increased. After we matched our snow core sample to the depth of the hole, the next two people in the assembly line, the snow core sawer, cut the snow core into 10 cm segments. We treated each of these 10 cm segments as individual samples. We measured the top and bottom diameters and the mass of each segment using a field scale, so that we could calculate the density of the sample later. The next person in the assembly line, the master note keeper, carefully recorded all these measurements. The master note keeper also kept track of any ice lenses, layers of ice within the snow core, in each sample. The master note keeper handed off the baggie holding the snow core segment to yet another member of the assembly line, the snow core pulverizer. The snow core pulverizer had perhaps the most entertaining job, breaking the snow core up into tiny little pieces. Accomplished via fist pounding and sometimes the use of a hammer, the goal is to break up and mix all of the snow core segment particles together, to make them as uniform in size as possible. Because we did not have enough sample bottles, or helicopter space, to carry out the entire snow core, we filled two sample bottles with the pulverized snow from each 10 cm segment. Pulverizing the segment helps ensure that the snow core pieces bottled are representative of the entire 10cm segment and not just the top or bottom part. Last, but not least of our tasks, the bottle labeler was responsible for marking all the sample bottles with the core segment label, so that back at the lab everyone knows which bottle goes with which part of the snow core.

Caption: Field staffer Matt Pickart and faculty member Natalie Kehrwald measure the snow core section, camouflaged on the snow workbench. Biogeochemistry students Molly Peek, Annie Holt, and faculty member Sarah Fortner bottle and label samples in the background. Photo credit: Annie Zaccarin.

Caption: Field staffer Matt Pickart and faculty member Natalie Kehrwald measure the snow core section, camouflaged on the snow workbench. Biogeochemistry students Molly Peek, Annie Holt, and faculty member Sarah Fortner bottle and label samples in the background.
Photo credit: Annie Zaccarin.

These snow cores will travel, from our backpacks, hundreds of miles via helicopter, car, and airplane to get to a laboratory to be tested for inclusions. These inclusions will function as proxies for different characteristics and changes occurring on the Icefield. The inclusions we will be testing for are isotopes, major ion content, snow density, levoglucosan (which is a chemical produced through burning plant biomass), and dust particles. Through these five things, we will be able to understand changing precipitation and wind patterns, temperature fluxes, types of rock surrounding the glaciers, and the quantity of forest fires in the area and if they are affecting the Icefield melt. Independently, each test is a little clue about the Icefield health and together it can make a more encompassing picture.

The Juneau Icefield is the fifth largest Icefield in the western hemisphere and determining whether changes are occurring, such as increased precipitation or ash deposits, are important factors in hypothesizing its present and future melt patterns. Since these cores can go back approximately 3-5 years depending on depth, we can compare this year’s annual melt, precipitation, and wind data to previous year’s data as a way to put current changes into perspective. Through these little microscopic changes in the snow, we can gain huge amounts of information on the Icefield's present and future health. And this whole process starts with a group of excited students enjoying the day and stuffing snow inside small bottles.

This brings us back to our makeshift conveyor belt of snow chunks, and what marked the end of the day’s sample collection. Our snow core reached an impressive 9.2 meters depth, which contains snow dating back 3-4 years. We packed the hundreds of sample bottles away into our bags, ready to be carry them back to camp. After taking off a layer and grabbing a quick snack, we all put on our skis and started the long trek back to camp for supper. We gazed at the tall, mountainous beauty of the Storm Range, hypothesized about what might be cooking for supper, and reflected on how lucky we are to learn science in a place as wonderful as the Juneau Icefield.

To learn more about the potential links between snow cores and forest fires, take a listen to this podcast by Elizabeth Jenkins about our group’s snow coring on the icefield.

The JIRP 2017 Biogeochemistry team at Camp 18. From left to right: Kiana Ziola, Dr. Sarah Fortner, Auri Clark, Molly Peek, Annie Zaccarin, Kit Cunningham, Annie Holt, Chris Miele and Dr. Natalie Kehrwald.

The JIRP 2017 Biogeochemistry team at Camp 18. From left to right: Kiana Ziola, Dr. Sarah Fortner, Auri Clark, Molly Peek, Annie Zaccarin, Kit Cunningham, Annie Holt, Chris Miele and Dr. Natalie Kehrwald.

 

 

Meet Chuck - Our Field Spectroradiometer

Meet Chuck – Our Field Spectroradiometer

Shawnee Reynoso

Sonoma State University

Reflectance. To most of us, it is just light bouncing back from a surface. Most of us refer to it when talking about a mirror or road signs. To a JIRPer, it is the reason behind our most frequent and prominent sunburns. As a glaciologist, reflectance is the key to understanding the relationship between incoming solar radiation, glaciers, and melt. When dust or ash or algae is deposited on a glacier’s surface, it gets darker and melts more. It is important for us glaciologists to measure and understand these processes. But how?

To measure the glacier surface reflectance, JIRP faculty member Allen Pope introduced us to the field spectroradiometer. We named it Chuck. Why you may ask? Because it stuck. That’s pretty much the only requirement to name things here at JIRP.

Chuck the field spectroradiometer is a lightweight box you can easily carry into the field. So what does a spectroradiometer do? It measures the amount of visible and near-infrared light being reflected off a surface. Along with the spectroradiometer comes a Spectralon panel. Spectralon is a ceramic white palette which is very bright in almost all wavelengths, making it close to 100% reflective. This Spectralon is used as a reference for how much light is present where you are currently taking surface reflectance measurements.

Deirdre Collins, Brittany Ooman, and Kate Bartell discuss reflectance data in the field. Photo by Shawnee Reynoso.

Deirdre Collins, Brittany Ooman, and Kate Bartell discuss reflectance data in the field. Photo by Shawnee Reynoso.

To use Chuck the spectroradiometer, you hold it as far away from you as possible and point it at your intended surface. First, you take a snap of your Spectralon to get a reference reflectance. This device is highly sensitive meaning that the color clothing you are wearing or your shadow can significantly influence its results. Next, you take a measurement of your surface and then you can see a graph on the computer screen showing your results. This graph shows highs and lows throughout visible and near-infrared light indicating which colors are being reflected and which are being absorbed.

Excited at how easy it was to use Chuck, we ran around camp and found various surfaces to measure and then compare. We pointed Chuck at brightly colored clothing, green moss, white snow, dark pools of water, and more! In measuring the reflectance of a reddish-tan granite, the graph peaked near the red point of visible light. This is the result we would have expected considering the tint of the rock. White snow matched up with our expectation of a bright and even reflectance spectrum throughout the visible light (because white is made up of all colors of light) but darker in the near infra-red (which is typical), and so our results made logical sense, which is always encouraging.

Deirdre Collins uses Chuck the Field Spectroradiometer to investigate the reflectance of various surfaces near Camp 18. Photo by Shawnee Reynoso.

Deirdre Collins uses Chuck the Field Spectroradiometer to investigate the reflectance of various surfaces near Camp 18. Photo by Shawnee Reynoso.

This exercise allowed us first hand experience with one of the research tools used by scientists. Allen’s research then uses this type of field data to help better interpret satellite imagery, for example. We were able to explore potential for what we could learn being able to get this data from specific locations in the field. Automatically retrieving the data also allowed us to consider and discuss the data while we were still collecting it in the field. (On another day, we used the data to calculate how much darker algae on the snow made the surface.) Aside from data collecting this was a fun activity that allowed me to understand reflectance in a clearer way then I had previously.

 

Gilkey Trench Fieldwork Adventure

By The Gilkey Trench Crew (Jamie Bradshaw, William Jenkins, Jon Doty, and Justyna Dudek)

While many students already started the fieldwork for their projects at Camp 10 and even Camp 18, five students have been anxiously awaiting to begin their fieldwork in the Gilkey Trench. The Gilkey Trench is the magnificent view that you see from Camp 18 where the Gilkey, Vaughan-Lewis, the Unnamed and many other glaciers connect and flow down through the steep, glacially carved, 2,000 foot deep valley. The Trench is filled with beautiful curving medial moraines and jaw dropping ogives created by ice falls. Getting to such a beautiful place is not easy and well worth a full day’s effort.

Descending "The Cleaver" - approaching the start of the series of fixed ropes - with the Gilkey Trench in the background.  Photo by Adam Toolanen

On Wednesday, July 31st, these students and four safety staff members departed Camp 18 for our camp on the bare glacier ice in the sunshine. The trick to getting to the glacier is descending what is affectionately called “The Cleaver.” The Cleaver is the 2,000 feet of bedrock that sits between Camp 18 and the glaciers below.  The descent was led by senior staffer Scott McGee, who has done the route many, many times. The first half of the route was going down steep snow slopes until we got to a vegetated area called “The Heather Camp.” This is where the fixed ropes began.

Waiting in a safe location - protected from rockfall from above - for their turn to descend the next section of fixed ropes.  Photo by Adam Toolanen. 

Here, the students and staff put on helmets and harnesses and tied into the fixed ropes with a knot called a prussik. This rope system served as a back up in case there was a slip on the steep, unstable terrain.  Fixed ropes were used for the last half of the descent because the route became steeper and more exposed. Because the glacier is melting, new bedrock and rock debris is left behind. This makes finding new routes difficult and challenging in the unstable footing. After 11 very long hours, the students and staff safely and happily arrived at our camp in the Gilkey Trench during a magnificent sunset.

Scott McGee scouts the lowest section of the descent made of freshly exposed bedrock, and precariously deposited boulders left by the rapidly thinning Gilkey Glacier.  Photo by Jeffrey Barbee. 

The next two days were spent collecting data from the field. A brief explanation of the students’ projects in the Gilkey Trench are below:

Jamie Bradshaw - Surface Ablation of the Gilkey Glacier

For my project, I looked at the ablation, or melt rates, of the Gilkey Glacier. In May 2013, wires were steam drilled into the ice for Dr. Anthony Arendt at the University of Alaska Fairbanks (also a visiting JIRP Faculty member earlier in the summer). My task was to find these wires and measure how much wire was exposed. Luckily the sites came with known GPS coordinates and had a wire tetrahedron with bright orange flagging attached to it, so it was fairly easy to find in the rolling, mildly crevassed terrain of the Gilkey Glacier. By knowing the length of the wire exposed at the time of installation (which I will find out upon returning to civilization) and measuring the length of wire exposed in August, the ablation can be determined. This becomes important because once the area of the glacier is known, the total amount of melt water runoff from the glacier to the ocean can be calculated.

Jamie Bradshaw photo documents one of the ablation-measurement sites on Gilkely Glacier.  As the glacier surface melts, more wire (at Jamie's feet) is exposed.  Photo by Jeffrey Kavanaugh. 

William Jenkins - Ogive Survey

My research in the Gilkey Trench was focused on the ogives, also called Forbes Bands, which form at the base of the Vaughan Lewis Icefall, adjacent to Camp 18. These interesting features in the ice are annual formations that only appear beneath fast flowing icefalls. It is commonly accepted that their light and dark banding represents the variations between summer and winter ice that has made its way through the icefall in one year. Summer ice, which is subjected to wind blown particulates and increased melt, constitutes the dark bands of the ogives and forms the trough of their frozen wave-like appearance. The white winter ice is composed of that year’s snowfall, and forms the crests of the wave bulges. 

William Jenkins surveys one of the Gilkey Glacier ogives with GPS.  "The Cleaver" is the ridge of rock in the background, with the Vaughan Lewis Icefall on the right.  Photo by Jamie Bradshaw. 

The purpose of my study was to determine how fast this area of the Gilkey Glacier was thinning in comparison to previous years. In order to determine this rate, I conducted a longitudinal GPS survey, with the help of Scott McGee, that had previously been carried out from the years 2001-2007. As a result of the glacier’s rapid thinning rate, I’ll be able to calculate its subsidence by the changes in the elevation of the survey over time. I will also compare the data I observe with the Vaughan Lewis mass-balance data that JIRP has collected over the years. This comparison will allow me to correlate the changes in annual precipitation with the transformations in the ogives wavelength and amplitude over time. The relationship between mass balance and ogive structure will shed light on the future transformations of the ogives and Vaughan-Lewis Glacier as a whole.    

Panorama of one of the ogives near the base of the Vaughan Lewis Icefall (in the background).  Photo by William Jenkins. 

Justyna Dudek - Photogrammetry

The main objective of my project was to create an up to date digital terrain model (DTM) of the Vaughan Lewis Icefall flowing down from Camp 18 into the Gilkey Trench. A digital terrain model describes the 3-dimentional position of surface points and objects, and can be used to retrieve information about geometrical properties of glaciers. In order to create the model, I decided to explore the procedures and tools available within the field of digital photogrammetry, a practical method which allows carrying out non-contact measurements of inaccessible terrain (very useful for areas such as icefalls, which for the sake of avalanches and falling seracs, might be too dangerous for exploration or measurements on their actual surface). The baseline dataset for creating the DTM of Vaughan Lewis Icefall  were recorded on the first, sunny and cloudless day of our stay in the Trench. With the guidance from Paul Illsley (present via radio from Camp 18) and help from my colleagues Jeff Barbee and Jon Doty (present on the Gilkey Trench), I set up the three profiles along which we collected the data in the form of terrestrial photogrammetric stereo pairs and ground control points (GCP). The database created by our team will be subsequently processed in order create a DTM which can constitute a reliable, starting point for further research in this area in the future.



Paul Illsley overlooks the Vaughan Lewis Icefall from a terrestrial photogrammetry station near Camp 18.  Photo by Mira Dutschke. 

Jon Doty - Nunatak Biology

My path into the trench followed a slightly different approach than the other students who reached the Gilkey Trench via the Cleaver descent.  Ben Partan – Senior Staff member in charge of camp maintenance – and I were brought down to the Gilkey via helicopter from Camp 18 to Camp 19, with a load of material to fix up the camp, which sees infrequent use. After two days repairing the roof, and siding, as well as swamping the camp interior, we descended into the trench. During our descent we made four stops at progressively lower elevations, conducting a botanical survey. At each site I recorded all plant species present, the compass orientation of the plot, elevation, and tried to keep an eye out for faunal interaction, and any other interesting features of the site. 

Ben Partan repairs the C 19 roof.  The upper Gilkey Glacier is in the background.  Photo by Jon Doty. 

As we dropped down closer to the surface of Gilkey Glacier - biodiversity plummeted. My final site featured only a single species of plant, as opposed to nearly twenty at the highest point of my survey. This loss of biodiversity can be tied to the recession of the Gilkey exposing new substrates, and the time required for mosses and lichens to reach the area and for soil to develop. Using a rough dating technique called lichenometry, we can gain insight as to the amount of time each site has been exposed by the recession of the glacier. The lichen species Rhizocarpon geographicum grows about 1 cm for every 100 years and is very common. Its absence at the lowest two sites is therefore noticeable, and signals that these sites were only recently revealed.

My survey is paired with another conducted by Molly Blakowski on the southerly oriented C 18 nunatak. These two slopes face each other with the Gilkey separating them. We plan on comparing the results of our surveys to determine what affects the differences of aspect have on the vegetation.   It was an absolute pleasure to join back up with the group and explore the Trench, and true fun to climb up the Cleaver and reunite with the rest of the JIRPers at C 18. 

The 2013 Gilkey Trench Crew (left to right): Jeff Kavanaugh, Jeff Barbee, Justyna Dudek, Jamie Bradshaw, Adam Toolanen, Adam Taylor, Jon Doty and William Jenkins. Photo by Jeffrey Kavanaugh

In closing, on August 3rd, the Gilkey Trench Crew packed up camp and headed towards the Cleaver to ascend back to life at Camp 18. Again, we tied into fixed ropes, had a remarkably beautiful day and had a safe climb up the Cleaver. The Gilkey Trench Fieldwork Adventure had been a success and possibly, the icing on the cake for all crew members.

Additional photos from the Gilkey Trench Fieldwork Adventure.  Click on any of the images below to open a slideshow with all photos and captions:     

Back with JIRP

By P. Jay Fleisher, Director Emeritus

JIRP ’68, ’69, ’79, ’86. ’87, ’93, '10, ’11, ’13

It is a pleasure and privilege to be back with JIRP (Juneau Icefield Research Program) after a one-year hiatus.  My initial JIRP experience decades ago was followed when I returned several times in subsequent years as a visiting faculty.  The Program, initiated and directed by Dr. Maynard M. Miller, evolved into a superb training ground for students heading to careers in Glaciology, Glacial Geology, Climate Science, and Arctic Sciences.  It is gratifying to see that the same high level of spirit and enthusiasm continues today in the current staff and students.

 

Dr. P. Jay Fleisher leads a geology field trip near Camp 10.  Photo by Mira Dutschke

Situated on the “high ice” central to the icefield, Camp-10 is currently the hub of research involving field measurements on multiple glaciers related to icefield mass balance and a variety of precision GPS projects that monitor glacier movement and elevation.  The scientific staff is eager to involve an enthusiastic group of 23 students (13 women and 10 men) who rotate in and out of projects, while attending to the logistical tasks of running the field camp.  An interesting variety of independent student projects is currently beginning formulated.  Soon the entire operation will shift to Camp-18 situated at the head of the Gilkey Trench, which in my humble opinion is the most photogenic place in all of Alaska.  The students will make the journey (about 15 miles) on skis, as they did two weeks ago when traversing from C-17 (20 miles) situated on the southern edge of the icefield and perched above Juneau.  Unfortunately, I am scheduled to depart prior to the C-18 move and will have to bid farewell to this dynamic group of students and staff.  But before I go I will offer the JIRP 2013 students a few farewell comments, comments that I hope will inspire them in their future efforts and perhaps inspire you as well.

My advice is to seek a mentor, one who will provide guidance when defining career goals.  For me their were three; my father who taught me, “if its worth doing, its worth doing right”, my wrestling coach who offered, “as you approach an initial goal, set another”, and finally a college professor who said to me years into my teaching career, “don’t tell me what you plan to do, tell me what’ve done”.  

I will advise the students “to follow their bliss, never stop questioning, and to find something to love”. 

Within this isolated icefield community, where the benefits of common values resonate most meaningfully, I hope the JIRPers will find inspiration and motivation in my comments.

So, until my return, hopefully next summer, I will add my name to the wooden rafters that record the annual roster of participants that goes back decades.

A Reconnaissance Mission with GPS Receivers

By Brooke Stamper

With safety training and ski practice behind us at Camp-17, we have begun to “hit it hard” as M. M. Miller would put it. Our daily routines have transitioned from gearing up to be outside and gathering our “glacier legs”, to spending time inside working on our research  projects.  The opportunities for place-based education are endless on the icefield and many students are taking advantage of the resources provided. I recently took advantage of an opportunity to set up GPS satellite receivers with Jason Amundson, Assistant Professor of Geophysics at the University of Alaska Southeast.

Jason and I rode on a snow machine and towed “the coffin”, a storage container with the bulky equipment in it. We traveled seven miles down glacier to a predetermined transect and placed our first of four satellite receivers just below the equilibrium line altitude, where the annual average snow accumulation and ablation are equal. We placed an additional three receivers at equal distances upglacier until we were at the convergence of the Matthes Glacier and Taku Glacier.  The GPS receivers will continuously track the velocity of the glacier over a one-week period to determine what portions of the glacier respond most strongly to meltwater input, and to what degree.  The project is simply exploratory at this stage.  Our hypothesis is that the daily variation in glacier velocity will be higher in the ablation area rather than on the “high ice” in the accumulation area.

The historical and current GPS data collection has been at specific points on the icefield to gather long-term annual data on surface elevation and velocity.  Most notably, Scott McGee and Ben Slavin set up stakes at set locations along a line that runs across the Taku Glacier from JIRP’s Cook Shack to Shoehorn Peak as well as a second set of stakes directly parallel to those stakes but starting from our favorite outhouse, curiously named “Dream Land”. On these stakes are placed black trash bags to allow us to better see the daily flow of Taku Glacier.  Eventually, the stakes will begin to arc and there will be noticeable change in location of the stakes. This will give us a fantastic example of strain on the icefield and an explanation as to why there are more crevasses on the edges of glaciers as compared to the center. Because the margins of the glacier are influenced by friction, the differences in flow rates are greater; therefore, there are more crevasses we must mind when downhill skiing from the Nunatak that Camp-10 sits on.

Although all of the students have begun to work independently on our projects, we are all aware that our efforts, in total, are for the betterment of the knowledge and understanding of the Juneau Icefield. Together as classmates and expedition-mates we are all here for the furthering of science on glacial dynamics and how this specific environment fits into the greater Earth system.

Links

The Crevasse Zone:  GPS Glacier Surveying on the Juneau Icefield, Alaska - Scott McGee's great website devoted to JIRP surveying efforts.


Glaciers 101

By Grayson Carlile

Since our arrival at Camp 10 we have shifted gears from safety and expedition training to science . Our time has been spent developing our individual research projects and receiving lectures from an exceptional group of faculty. We are beginning to delve into the details of how the icefield functions.

So before we begin filling the blog with our research and theirs, we thought it appropriate to give a brief explanation of what a glacier is - how snow is transformed into the spectacular rivers of ice that we are wandering among this summer.

The rivers of ice we know as glaciers form from the accumulation of enormous quantities of snow.  Mendenhall Glacier, Alaska.  Photo by Adam Taylor

It all starts with the same snow you might have falling in your backyard during the winter. Most of us, however, do not have glaciers in our backyards, so there must be a few other criteria. Here is where snow quantity and local climate come into play. There has to be enough snowfall that summer temperatures will not melt it all away before the snow returns. Some of the snow that has accumulated has to persist through the entire year.

Then the process has to repeat itself...over, and over, and over again. As time goes on, individual snowflakes begin to metamorphose – their delicate, spindly structures gradually breaking down through a combination of melting, refreezing, and pressure from overlying snow. The resulting products are rounded ice granules called

firn. In the final step on the journey to becoming glacial ice, these firn granules meld into larger ice crystals that fit together like pieces in a three dimensional jigsaw puzzle.

The transformation of snow to glacial ice can take decades to centuries depending on the consistency (wet or dry) and quantity of snow that falls. Once the ice has formed, it can begin to take on the properties of a glacier. As mentioned above, glaciers are rivers of ice. By definition they are moving - pulled downhill by the force of gravity. So in order for the ice to become a glacier, something has to change within the ice in order for it to flow.

Once the ice is a few tens of meters thick, there is enough stress on the underlying ice that it begins to behave viscously - that is, similar to a fluid - and can finally deform and flow. To understand how this works, imagine a ball of silly putty. If you work it in your hands, applying pressure, you can get it to start stretching and slowly flowing. This is essentially what happens to the underlying ice in the 70 meters of accumulation. The pressure of the overlying ice brings it to a consistency that allows it to flow. Once it has reached this point, it begins to succumb to the force of gravity and flow down a valley or across a continent. In addition to this viscous flow, some glaciers such as those that exist in warmer climates, may also flow over the bedrock or sediments at their bases.

So while a reference to glaciers may conjure images of the Arctic or Antarctica in the minds of many, with the right conditions glaciers can form almost anywhere – from the summit of Mt. Kilimanjaro in Africa, to the South Island of New Zealand, to the Cascade volcanoes of Washington State. However, glaciers can and do behave differently in these various locations. Some places, such as Southeast Alaska, where precipitation and cool temperatures are widespread and rampant, cater to more than just a single glacier, producing complex networks of glaciers such as the Juneau Icefield. Here the Coast Mountains receive more snow than almost any other place on Earth. The vast distribution of enormous quantities of snow has created nearly 1500 square miles of glaciated terrain that drains the rugged mountains – flowing east into British Columbia and west into the salty waters of Alaska’s Inside Passage.

Interview with Gabrielle Gascon

By Leah Nelson

Gabrielle Gascon is currently finishing her PhD in the Department of Earth and Atmospheric Sciences at the University of Alberta, Edmonton Canada. Her work focuses on ice-climate interactions on the Devon Ice Cap, Canada, where she has participated in several field seasons. In her spare time, she enjoys swimming, camping and canning fruits and vegetables.

Gabrielle Gascon at sunny Camp 10.  Photo by Sarah Bouckoms

Leah Nelson: Is this your first time on the Juneau Icefield?
Gabrielle Gascon: Yes, I’ll be here lecturing and helping students with their projects that are based on ice-climate interactions.

LN: What research are you working on?
GG: My work is based in the Canadian Arctic, where I focus on ice-climate interactions using a variety of field observations combined with numerical modeling.  Using data gathered from weather stations, net radiometers, and ground penetrating radar we can investigate melt season characteristic changes.

LN: How did you get interested in studying ice-climate interactions?
GG: While working on my masters degree at McGill University, I was studying winter storms from Iqaluit in the Canadian Arctic.  We used many ground base instruments but we also collected data using an aircraft to fly into storms.  While flying over the Penny Ice Cap, I was struck by the many interactions that are possible between glaciers and climate.  Both of the systems depend on many variables which makes the possible interactions so interesting to study.

LN: What is the greatest adventure that your research has taken you on?
GG: While doing research on Devon Island, I spent five weeks in an eight by eight meter tent.  The experience of exploring the largest uninhabited island in the world was rewarding.

LN: If you could bring any person on an expedition, who would it be?
GG: Peter, my boyfriend.  He does similar field work and was with me during those five weeks in the tiny tent on Devon Island.  Otherwise, I’d bring any one of my family members to show them what I’m working on for my research.

LN: Why is glaciology research important for non-scientists?
GG: Glaciology is important for everyone to understand because glaciers act as freshwater reservoirs and impact sea level.  For example, in the Rocky Mountains, glaciers are the main source of fresh water for many cities.  The melting of larger glaciers, such as the icecaps, could greatly influence sea level, which in turn has a profound effect on people that inhabit coastal areas.  The cryosphere is a key component of the earth system; changes within in it are significant to all of us.

LN: What advice would you give to aspiring young scientists?
GG: I would tell young scientists to decide your career and area of study based on your interests and not on potential salary.  If you find that you don’t like what you’re doing, change it.  And don’t put your career above your personal life -- be happy. 

An Interview with Dr. Anthony Arendt

By Patrick Englehardt

Glaciologist Anthony Arendt grew up in Edmonton, Alberta, where his deep connections to the Canadian Rockies fostered his love for science and nature. Growing up Anthony often visited the Athabasca Glacier, where he fondly recalled traveling onto the glacier in track vehicles with his family. Once in college his passion for mountaineering and science was fostered, and he decided that he wanted to pursue a career in Earth science where his passions could be fulfilled.  

Dr. Anthony Arendt gives an evening lecture to JIRP students in the Camp 17 library.  Photo:  Jeff Barbee

Patrick Englehardt: What is your research focus?
Anthony Arendt: I focus on understanding how glaciers change in response to climate, with an emphasis on predicting how global sea level and local water resources are affected.

Patrick Englehardt: Where has your research taken you?
Anthony Arendt: My first glacial project took place on Ellesmere Island in northern Canada, where I spent three summers conducting research.  I have also traveled to the North West Territories, Alaska, Greenland, and Antarctica.

Patrick Englehardt: Why do you conduct your research?
Anthony Arendt: Glacial change is a large contributor to rising sea level, which has significant societal impacts and global implications. It is especially important to understand how these changes will affect coastal communities, local water resources and agriculture.

Patrick Englehardt: What has been your greatest challenge?
Anthony Arendt: The first few years of my PhD were really challenging. During this time I figured out that Alaskan field work had a steep learning curve. I had to hone my mountaineering, glacial travel and survival skills and deal with the incredibly remote Alaskan wilderness. During the second year of my PhD I had a harrowing experience, falling into a glacial river and losing all of my glacier gear. This was the low point of my career and I seriously thought of quitting.

Patrick Englehardt: What kept you from giving up?
Anthony Arendt: I had a lot of support from family, friends and colleagues, all of whom encouraged me not to give up. I think my interest in glaciers also kept me going, and I knew that I could not learn all of these amazing things anywhere else but in Alaska. I’m glad I never gave up and I stuck with it, because my career improved after that.

Patrick Englehardt: Who was your greatest inspiration growing up?
Anthony Arendt: As a scientist it was David Suzuki. I remember, as a kid, watching him on television every week. He introduced me to new ideas about how we can care for the planet and mitigate climate change. What impressed me most was his honesty, something that has always stuck with me as I have strived to be fact-driven and honest with my research. Also I have been inspired by every advisor I have had during my career. Each has been a great mentor in their own right and helped me along the way.

Patrick Englehardt: How did you hear about JIRP?
Anthony Arendt: When I moved to Alaska in 2000 I heard about JIRP from a myriad of people, and I always wanted to take part in the program.  I had hoped to participate as a student but schedules and research always kept me from doing that. Jeff [Kavanaugh] approached me and asked if I would teach this year at JIRP and I happily obliged.  I was excited to finally be part of the long historical legacy of the many others before me, including my PhD supervisor [Keith Echelmeyer].

Patrick Englehardt: What suggestions would you have for aspiring scientists?
Anthony Arendt:
Students interested in a scientific career face numerous opportunities, and also many challenges. In addition to learning a broad range of technical and mathematical skills, scientists need to develop strong communication skills, due to the highly collaborative nature of research today. At the same time, we know some of the greatest scientific discoveries come from long periods of working in solitude. So, finding educational opportunities that balance these elements is really important.

Patrick Englehardt: Do you believe that there are educational opportunities where aspiring scientist can gain these skills?
Anthony Arendt:
I believe that JIRP provides great opportunities for developing these skills. I cannot think of a better environment for aspiring scientist to hone their research and safety skills while fostering a strong sense of community. At JIRP, students work towards a common goal while simultaneously conducting unique scientific research.  JIRP is an excellent microcosm of the real scientific community where a love of nature and science connect people and connections are made for life.

Patrick Englehardt: If you had not become a scientist what would you do?
Anthony Arendt:
No question, I would be a famous Jazz musician! I looked into musical colleges and I play piano, and I continue to play as a hobby.  

Dr. Anthony Arendt.  Photo:  Mira Dutschke

Tied to a String

By Stephanie Streich, Photos by Mira Dutschke and Jeff Kavanaugh

Chrissy McCabe, Alistair Morgan, William Jenkins, Adam Taylor and others practice their knots at Camp 17 on the Juneau Icefield.  Photo:  Mira Dutschke

At Camp 17, students have been roped in and all tied up, becoming familiar with various knots. A critical part of our daily routine has been learning and practicing the knots that are crucial to travel safely on the icefield. The Figure-8, the Butterfly and the Double Fisherman are just some of the knots that will protect us against the dangers of crevasses and ice caves that are hidden within glaciers. The Prussik knot and the climbing harness are sometimes the only lifeline that attach you to the other members of your trail party as you travel across this vast white wilderness of snow and ice. Before we expose ourselves to the real life dangers of the field, we developed our climbing skills in a safer and warmer environment: the kitchen.

Climbing ropes hanging to dry in the cookshack at Camp 17 on the Juneau Icefield.  Photo:  Mira Dutschke

For practice all the students piled into the cookshack to climb up ropes attached to the ceiling. Using the knots we learned, we used two Prussik slings and attached them to the ropes and our harnesses. I have to admit, I was pretty hesitant to get up the rope as I was standing in line waiting for my turn. I was unsure if two skinny strings attached to a rope would actually hold my weight and enable me to elevate myself high into the air. Once I got attached to the rope I realized that the harness did a lot of the work for me, and I started having a blast. The harness loops around our waist and legs, linking us to the main line with a carabiner. With a long Prussik for the legs and a short Prussik from the harness to the rope I was able to hoist myself up the line. It was a great feeling of relief hanging in thin air by a string, gradually climbing up, knowing that I was not going to fall down. It was so easy! Climbing was definitely not as difficult as it seemed watching my fellow JIRPers tackling the rope. Getting down, however, was another story and quite a challenge. It would be rare to need to Prussik down a rope, but I'm going to have to work on that.

Author Stephanie Streich at the top of the rope after practicing with her prussiks in the camp cookshack.  Photo:  Jeff Kavanaugh