Trip to the Northwest Branch of Taku Glacier

By Eric Keenan, U. Washington, and Christoph Suhr, Whitman College

One method that scientists use to evaluate the health of glaciers is by digging holes into the glacier surface. On the Juneau Icefield Research Program, students and scientists use this method - known as mass balance - to determine the total amount of water in the form of ice and snow that has accumulated at pre-determined points on the Juneau Icefield in the past year. These measures have been collected since 1948, forming the second longest lasting mass balance record in the world. Recently, fifteen students, faculty, and staff embarked on a three day expedition to the Northwest Branch of Taku Glacier to carry on a part of this long-term survey.

Part of the mass balance group skiing to their pit located behind Emperor Peak. Photo credit: Julian Cross.

Part of the mass balance group skiing to their pit located behind Emperor Peak. Photo credit: Julian Cross.

To reach the pits on the NW Branch of Taku Glacier, our group skied approximately thirteen kilometers from Camp 10, and established an overnight basecamp complete with dug-out tent platforms, latrines, sheltered gear trenches, and a cook tent. The second day of the expedition consisted of digging the mass balance pits higher up the NW Branch of Taku Glacier, too far afield to access in a day trip from any permanent JIRP camp. On the third and final day of the expedition we awoke to sunny skies, packed up our camp, and enjoyed the beautiful weather for our ski back to Camp 10.

To conduct the mass balance research, on each day of the expedition the fifteen participants would split into three groups, and head from basecamp to different locations to dig their mass balance pits. To document the health of the glacier, the students and scientists dug tirelessly down to the previous summer’s surface, sometimes having to dig over four meters into the glacier! By reaching the previous summer’s surface, the students could sample the snow that fell in the past year, weigh it, and from those data calculate the total mass of ice and snow that was added to that part of Taku Glacier by snowfall. With this information, total mass of snow and ice added in the winter can be compared with the mass of ice lost to summer melt. This comparison can be thought of as ‘balancing the glaciers checkbook,’ and can be used to evaluate the glacier’s health.

Basecamp for the NW Branch trip, consisting of four sleeping tents, and gear, cook, and dining tents. Photo credit: Julian Cross.

Basecamp for the NW Branch trip, consisting of four sleeping tents, and gear, cook, and dining tents. Photo credit: Julian Cross.

JIRP 2016 - Success at AGU

Matt Beedle

JIRP Director of Academics and Research

As we work through the application materials for JIRP's prospective 2017 cohort (amazing applicants, by the way!), I'm reminiscing on this process from a year ago and the phenomenal JIRP class of 2016. JIRP, of course, is a research program, an educational expedition. The more years I'm involved in JIRP, however, the more I realize that it is the community of JIRP that is transformative. In the words of Dr. Maynard Miller, reflecting on why he was so drawn to the program he helped shape and led for decades:

I can’t get away, because you’re all so wonderful!

After completing the summer field season, the 2016 cohort went their separate ways, but continued their summer research, building towards the American Geophysical Union's Fall Meeting in early December where they presented their work. Half of our 2016 cohort of 32 made the trek to San Francisco to present, expand their scientific understanding and connections, and enjoy a number of gatherings with JIRP alumni and faculty. Engaging once again with this talented group of young scientists, introducing them to the larger JIRP family of alumni and faculty, and helping them make connections on their career paths was a real highlight of AGU 2016. The JIRP team is proud of your work and we are excited to build upon these efforts with JIRP's 2017 students!

Please see the images and text below for a team-by-team synopsis of student research presented at the 2016 AGU Fall Meeting:

BIOGEOCHEMISTRY: Team members Annie Holt, Annie Zaccarin, Auri Clark and Molly Peek (left to right in image below), present their group's work.

Abstract: Previous work has characterized chemical weathering in polar, polythermal, and alpine settings. However, chemical weathering and the role of supraglacial streams within the carbon cycle on the Juneau Icefield glacial system is not well documented. This study examines the concentration and spatial variability of alkalinity and major ions present in the ablation zone of the Llewellyn glacier, which is on the northeast side of the Icefield in Canada.

In particular, we explore how differences in chemistry are associated with source area reflectivity. By conducting measurements to characterize melt chemistry and alkalinity, we present results of a spatial variation survey of the Llewellyn Glacier ablation zone and relate the findings to surface albedo. We sample 30 locations in August 2016 during the late ablation season using a Hach digital titrator, ion chromatograph and an albedometer to measure alkalinity, major ion concentrations and albedo respectively. We characterize the relation between alkalinity concentrations and dust patterns and compare our data to other glacial systems. This study contributes to the larger understanding of chemical weathering in glacial environments.


BOTANY/ECOLOGY: Deirdre Collins presents her team's work.

Abstract: Alpine environments are particularly vulnerable to climate change, and alpine plant populations of the Juneau Icefield are currently experiencing increased environmental stress. In this study, vascular plants on selected nunataks of the Juneau Icefield of the Coast Range Mountains are investigated. Sixty meter transects spanning an elevation range are collected along prominently vegetated portions of each study site. The population of vascular plants found is considered in relation to the nunatak soil microbiota, elevation, latitude, nunatak emergence and geology. Results indicate previously unknown variations in nunatak soil microbiota and provide baseline data that may be used for future studies.


GEOPHYSICS: Tae Hamm, Dr. Kiya Riverman and DJ Jarrin present the geophysics team's 2016 research.

Abstract: High resolution measurements of spatial ice thickness variability on the Juneau Icefield are critical to an understanding of current glacial dynamics in the Coast Mountains of Southeast Alaska. In particular, such data are lacking on the Taku Glacier, a tidewater glacier in the Juneau region whose unique advance has slowed in recent years.

Significantly, such information is necessary to develop an accurate description of ice dynamics as well as sub-surface hydrology and bedrock erosion. Utilizing relative gravimetry, we sought to modify existing parameterized models of ice thickness with field measurements taken along the centerline of the Taku. Here we present a three-dimensional representation of ice thickness for the Taku, based on in situ observations from July 2016. As the glacier approaches a potential period of rapid terminal retreat, this data gives refined physical information prior to this potential juncture in the tidewater cycle-an observation that may yield insight into marine ice sheet instabilities more broadly.


GPS SURVEY: Brittany Ooman (with the assistance of DJ Jarrin) presents the survey team's work from 2016.

Abstract: Glaciers are retreating at unprecedented rates worldwide, but the Taku Glacier in Southeast Alaska underwent a recent advance. As part of the Juneau Icefield Research Program, glacier surface elevation and short-term velocity are measured annually during the summer season along longitudinal and transverse profiles using a real time kinematic global positioning system (GPS).

We compared our survey results from 2016 to those of recent decades to determine changes in surface elevation and velocity over time. The observed changes are discussed in relation to the available bed topography data. In addition, we generated a detailed surface model and measured the pattern of local surface flow to constrain the location of the Matthes-Llewellyn divide, and determine if it is migrating through time. The results will help us understand the evolving dynamics of Taku glacier.


ISOTOPE GEOCHEMISTRY: Cezy Semnacher and Mo Michels present the 2016 efforts of the JIRP isotope team.

Abstract: The glaciers and climate of Southeast Alaska are currently changing, and the water isotopic record stored within these glaciers can act as an informant of this variability. Toward this end, it is necessary to understand the modern relationship between environmental factors and the patterns of water isotope variability. In this study, we present a spatio-temporal survey of water isotopes in precipitation on the Juneau Icefield of Southeast Alaska, carried out through the Juneau Icefield Research Program during the summer of 2016.

Samples were collected from 75 kilometers of surface transects, seven pits, and three cores of the annual snow pack, including repeat measurements to test for isotopic alteration from rainfall events. Measurements span three glaciers, a range of elevations, and multiple climate zones. Results, including those from annually repeated surface transects, were compared to data collected in the summers of 2012 and 2015.

Data from 2015 show an icefield-wide trend between δ18O values and elevation. However, a locally reversed trend was identified across the Taku Glacier. The data collected from this study will help to explain this unexpected result. Comparisons are made to other environmental factors including annual average temperature, distance from the coast, and the influence of different weather patterns.

Understanding the spatial and temporal patterns of isotopes across the Juneau Icefield will allow for a deeper understanding of the local relationship between these tracers and climate. This understanding is critical to interpreting water isotopes as a proxy for climate changes in the past.


MASS BALANCE: Dr. Shad O'Neel, Kate Bollen, Olivia Truax, Evan Koncewicz, Tai Rovzar and Alex Burkhart present the mass balance team's 2016 research.

Abstract: The Juneau Icefield Research Program has collected mass balance data over the last 70 years on the Taku and Lemon Creek glaciers. We analyze data from 2004-2016 to investigate the interannual variability in the accumulation gradients of these two glaciers from ground penetrating radar (GPR), probing, and snow pits. Understanding interannual variability of accumulation gradients on the Juneau Icefield will help us to interpret its long-term mass balance record.

The Lemon Creek Glacier is a small valley glacier on the southwest edge of the Icefield. GPR data was collected over the glacier surface in March 2015 and 2016. In July of 2014 and 2016, the accumulation area was probed for snow depth, and two snow pits were dug for snow depth and density. The accumulation gradients resulting from each method are compared between years to assess the interannnual variability of the accumulation gradient and the resulting glacier wide mass balance.

The Taku Glacier is the largest outlet glacier on the Juneau Icefield. We use three snow pits dug each year along the longitudinal profile of the glacier between ~1000m and ~1115m, the region that typically reflects the ELA. In 2004, 2005, 2010, 2011, and 2016, snow probing was continued in the central region of the Taku and the resulting gradients are compared to each other and to the gradients derived from the snow pits. We assess the resulting impact on glacier wide mass balance furthering our understanding of the state of these two well-monitored glaciers on the Juneau Icefield.


PLANNING FOR 2017: We are excited to build upon these research efforts and also expand in new and exciting research directions. Stay tuned for more information on our 2017 season in the coming weeks!

A portion of the JIRP crew at the 2016 AGU Fall Meeting gathers for dinner after a day of science in San Francisco.  Back row: Annie Zaccarin, Annie Holt, Olivia Truax, Evan Koncewicz, Kate Bollen, Molly Peek, Deirdre Collins, Matt Beedle, ????, Brad Markle, Tai Rovzar. Front row: DJ Jarrin, Cezy Semnacher, Chris McNeil

A portion of the JIRP crew at the 2016 AGU Fall Meeting gathers for dinner after a day of science in San Francisco.

Back row: Annie Zaccarin, Annie Holt, Olivia Truax, Evan Koncewicz, Kate Bollen, Molly Peek, Deirdre Collins, Matt Beedle, ????, Brad Markle, Tai Rovzar. Front row: DJ Jarrin, Cezy Semnacher, Chris McNeil

Taku Glacier: Anomaly of the Juneau Icefield

Kate Bollen

On a map of the Juneau Icefield, Taku Glacier is a distinguished ribbon that winds out of the southeast corner of the icefield as an outlet glacier. It’s remarkably large, even by Alaskan standards. It encompasses 671 square kilometers (Pelto et al, 2013) and measures about 5 kilometers across where it passes in front of Camp 10. It’s fed by four tributary glaciers that line its upper margins, and its outline is similar to the shape of Thailand. Taku Glacier is quite special, not only because it sets a stunning scene for JIRPers to admire from the porch of the Camp 10 cook shack, but also because it’s one of only a hand-full of glaciers in Alaska (and around the world, for that matter), that has been advancing (Pelto et al, 2013).

Shawnee Reynoso and Louise Borthwick sleeping out on the porch of the Camp 10 cook shack overlooking Taku Glacier. Photo: Kate Bollen

Shawnee Reynoso and Louise Borthwick sleeping out on the porch of the Camp 10 cook shack overlooking Taku Glacier. Photo: Kate Bollen

Until recently, Taku Glacier has been growing in mass. Indeed, the Taku looks unlike its neighbors as it descends toward the floodplain of the Taku River. The ice juts out over the small trees that live in its path, as the adjacent Norris Glacier looks as if it’s withering away, cracked and shrunken. Since most Alaskan glaciers are surrounded by forests that are actively creeping out onto the new ground exposed by glacial retreat, the sight of the Taku mowing over trees and shrubs as it slides down its broad valley is quite victorious to the glacier enthusiast.

Positions of the end of Taku Glacier from 1948 to 2014. Adapted from a figure by Chris McNeil.

Positions of the end of Taku Glacier from 1948 to 2014. Adapted from a figure by Chris McNeil.

Boundaries of Taku Glacier on the Juneau Icefield. Adapted from a figure by Chris McNeil.

Boundaries of Taku Glacier on the Juneau Icefield. Adapted from a figure by Chris McNeil.

Students Molly Peek and Shawnee Reynoso and faculty member Chris McNeil ski through thinly exposed crevasses on Taku Glacier below Camp 10 on a sunny day. Photo: Kate Bollen

Students Molly Peek and Shawnee Reynoso and faculty member Chris McNeil ski through thinly exposed crevasses on Taku Glacier below Camp 10 on a sunny day. Photo: Kate Bollen

There are two main causes behind the anomalous case of the Taku. First, the glacier has a unique hypsometry, which refers to the distribution of the glacier’s surface area with respect to elevation. Most of the Taku lies above 1200 meters above sea level, so it has a huge accumulation zone (the area where annual snowfall doesn’t completely melt by the end of the melt season) compared to the total surface area of the glacier. As a result, the majority of Taku Glacier can gain mass from falling snow each year. Second, Taku Glacier is a tidewater glacier. This may strike an observer as peculiar since the Taku currently flows into a river rather than the ocean, but this classification stands based on the Taku’s behavior and bed topography.

Olivia Truax collects snow depth data on the Northwest branch of Taku Glacier. Photo: Kate Bollen

Olivia Truax collects snow depth data on the Northwest branch of Taku Glacier. Photo: Kate Bollen

To understand the dynamics of Taku Glacier, we have to know the story of the tidewater glacier cycle. Here is a summary derived from a lecture delivered to JIRP students by Martin Truffer earlier this summer at Camp 17. As the end of a tidewater glacier, known as the terminus, rests in a fjord, the elevation of the glacier’s bed is below sea level. As a result, the melt water beneath the terminus of the glacier becomes pressurized so that it can still flow into the ocean despite the weight of the seawater column. The terminus is quickly eroded as big chunks of ice peel away during calving events and as warm sea water circulates against the terminus. Consequently, the glacier is driven into a rapid retreat, and it recoils up its valley until it reaches a resting point above sea level. There, the glacier is able to stabilize and to eventually begin an advance by pushing its dirty, icy terminus forward on a terminal moraine (a pile of sediment collected by the glacier at its terminus as it grinds forward). By advancing a homemade mound of sediment ahead of itself, the glacier can rest above the deep water of the fjord and the subglacial hydraulics are less pressurized, so the glacier is protected from the intense melting and erosion that previously drove it back. As it continues to bulge onward, the glacier eventually reaches a state where its surface balance nears zero, which means that its accumulation and ablation (melting) are equal. At this point, the glacier can reenter a rapid retreat as the tidewater glacier cycle continues.

A steamship floats in front of the Taku terminus during an earlier advancement of the glacier.

A steamship floats in front of the Taku terminus during an earlier advancement of the glacier.

As for the Taku, its bed doesn’t rise above sea level until an estimated 20 kilometers up-valley of its terminus (oral comm. Beem 2016). Additionally, the Taku has been in the advancement stage of the tidewater glacier cycle since 1850, but its advance has halted in the last two years (oral comm. Truffer, 2016). It’s too early to determine if the Taku has reached the end of its advance or to say that a rapid retreat is imminent. However, the reactions of the Taku and other glaciers to climate will have wide-spread impacts and can tell us quite a bit about the changing climate. Mountain glaciers account for less than 1% of global glacial ice volume, but their rapid rate of mass loss is responsible for one-third of the current observed sea level rise (Larsen et al., 2015). Additionally, glaciers play a big role in downstream ecosystems as they deliver nutrients and sediment as well as well as manipulate water flow, turbidity, and temperature (O’Neel et al., 2015). Consequently, these glaciers can almost directly impact where and how people near and far are living. The Taku and other glaciers captivate us as scientists and inspire us as humans to understand the complex systems in which we live.

References

Beem, Lucas. Oral communication 2016.

Larsen, C. F., E. Burgess, A. A. Arendt, S. O’Neel, A. J. Johnson, and C. Kienholz (2015), Surface melt dominates Alaska glacier mass balance, Geophys. Res. Lett., 42, 5902–5908, doi:10.1002/2015GL064349.

O’Neel, S. et al. 2015. Icefield-to-Ocean Linkages across the Northern Pacific Coastal Temperate Rainforest Ecosystem, BioScience, 65, 5, 499-512.

Pelto, M., J. Kavanaugh, and C. McNeil , Juneau Icefield Mass Balance Program 1946-2011, Earth Syst. Sci. Data, 5, 319-330, doi:10.5194/essd-5-319-2013.

Truffer, Martin. Oral communication 2016.

 

Pre-JIRP Readings: Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level

For this blog post, we'll provide some key points to think about rather than the questions as in previous posts.  We look forward to some stimulating discussions in Juneau!

The reading this week is as follows:

Arendt, A.A., Echelmeyer, K.A., Harrison, W.D., Lingle, C.S., Valentine, V.B., 2002. Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level. Science 297, 382–386.

Alaska represents only a small fraction of the world's glacier ice, but is among the largest sources to new water contributions to sea level rise.  To understand why, think about two buckets filled with the same amount of water.  Its a hot sunny day, and you and the buckets are hanging out in a parking lot. You trip over one bucket and spill it on the ground.  That spilled water will evaporate much more quickly than the water in the bucket, in part because the surface area to volume ratio has changed.  This is a good analogy to why Earth's mountain glaciers have more rapid rates of change than do the ice sheets. Climate and geography play a part as well, but this is a good place to start when thinking about differences between glaciers and ice sheet mass balance.

Another aspect to consider as you read this paper are the research methods used and possible errors associated with them.  All methods have errors, which can significantly impact research results.

That's all for today.  See you all soon!

Connecting Glaciology, Hydrology, and Ecology on the Juneau Icefield

By: Kim Quesnel, Stanford University; Lindsey Gulbrandsen, State University of New York, Oneonta; and Laurissa Christie, University of Guelph


Since the main focus of JIRP fieldwork is mass balance (digging snow pits to determine the annual health of the glacier), the hydrology group decided to examine the relationship between mass balance and stream flow on the Lemon Creek and Taku glaciers. Both glaciers have historic mass balance data and also feed into United States Geological Survey (USGS) gaged streams, giving us two datasets to use in our analysis. Additionally, we will also be using meteorological data (temperature and precipitation) in our models.

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   Laurissa cores a sample of snow in the mass balance pit. 

Laurissa cores a sample of snow in the mass balance pit. 

The goal of our project is to examine the fluxes in glacial accumulation and ablation and to determine the impact of changing glacier dynamics on downstream ecosystems (both terrestrial and marine) which are dependent on glacial melt water. For example, salmon habitats require specific streamflow and sediment conditions to spawn, and changes due to accelerated melt may impact their habitat and breeding environments. We are excited to see different relationships between all of the variables, and we are waiting to get back to our respective universities to continue to analyze data.

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   Kim looks at a supraglacial stream  .

Kim looks at a supraglacial stream.

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   French Alex, Kim, Laurissa, and Natalie measuring a stream.

French Alex, Kim, Laurissa, and Natalie measuring a stream.

In addition to looking at the overarching hydrology of icefield, we also took several field trips while we were at Camp 26 to look at the water features in the ablation zone. We mapped hydrologic features, looked at the evolution of supraglacial streams, and explored ice caves under the Llewellyn glacier. 

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   The hydrology group! Laurissa, Kim, Lindsey, and Carrie  .

The hydrology group! Laurissa, Kim, Lindsey, and Carrie.


Introduction to Digging Mass Balance Pits

by Carmen Braun   

Today marked the first day we weren’t all doing safety training!  While some JIRPers continued doing some safety training, others expanded our horizons to probing and surveying, and nine of us began digging mass balance pits.    After the standard morning time activities (wake up call, breakfast, and work duties), we started getting ready.  Considering the fact that most of us were already wet after our work duties, we all knew we were in for a cold, wet day. 

Those of us responsible for digging mass balance pits were divided up into two groups, each with a safety staff member to show us the ropes.  We skied north down the glacier for about half an hour before arriving at the dig location. The other group’s location was a bit closer to camp.  Upon arrival, we got to work right away, after covering our packs with our tarps in a futile attempt to keep them from getting wetter.  We dug, rotating positions from time to time, for about 4.5 hours.  That warms you up quickly!  My group was really quiet; I spent most of the time in a zone where the only thought in my head was where to shovel.  It was very meditative work.  The other group was chatting most of the time, which I’m sure created quite a different atmosphere. At one point, Dougal, one of the guys in the other group, started yelling out names of things he hates as he chopped at the snow. In these cold and wet conditions, I was very happy to just dig.   However, in nice weather, I can see how digging with a little music and good conversation would be great as well.

As for the actual digging of a pit, everyone starts in the pit until snow starts to accumulate around the edges.  At that point, one moves to clear the rim of snow and the other four start focusing on one quadrant each.  We would rotate from time to time at the beginning, but I think I spent about 3 hours in the same quadrant after that.  Eventually, you have one quadrant that is very deep, and then the other three become progressively shallower.  The one in the lowest quadrant eventually starts passing snow to people in higher ones so they don’t need to throw the snow up and out of the pit. 

This has been a low accumulation year, so we only had to dig to a depth of about 2.25 meters to find last year’s layer.  It was really fun to finally see all the structures people had been telling us about, like the ice lenses and the layer of less dense depth hoar that formed above the much more dense snow from last year.  We finished our pit before the other group, but they had all the scientific equipment so we skied up to their pit to grab that.  Most of our boots were at the point where water sloshed from the toes to heels and back each time the angle of our feet changed.  My overmitts had started retaining water long before, so each time I brought my poles up water splashed over my fingers.  We ended up just separating into two new groups, one to head back to camp, and one to do the measurements because so many of us were very cold at that point. 

I am pretty sure we all enjoyed ourselves, at least in the type B version of fun.  Below are a couple quotes from other students.

“If it’s raining it sucks” – Jenny

“I like it, it’s my friend” – Matt

“No matter how vertical you think the walls are, they’re not.” – Kelly

“A good way to stay warm in the freezing cold rain.” – Randall

“Chat through adversity.” - Randall

“Good way to get in shape.  Once we get to the dry parts I think it will be really fun!” – Natalie

“If I ever want to become an ice sculptor, digging mass balance pits will prepare me well.” – Danielle

Erik talked about how it’s the only way to really see the inside of a glacier, in a way we are evolutionarily developed to understand. He compared it to probing, which is completely uninformative for the senses we use.

“Sometimes it’s like highway construction, one person is working and five people are watching” – Tristan

(This was in reference to a pit we dug where the last annual layer was only 92 cm below the surface.  It ended up being about 1m3; we fit 7 people in there and took a couple selfies once all the science was done!)

The Pirates of Glacier Mass Balance

By Jon Doty

Mass balance is in many ways piratical by nature. There is a reason why a JIRPer often stumbles across pirate flags with the words "Mass Balance 2012" scrawled onto the walls of camp. We have our map, shovels to dig for treasure, and X marks the spot. However, our modern day plundering involves a somewhat different set of tools, and an altogether different goal. In lieu of a pirate ship, we ride our skis into the horizon, following a GPS in search of science. 

The mass-balance crew on the morning before skiing to the Demorest Glacier pit. Photo by Mary Gianotti.

Although I have lost touch with the outside world, I am told that the day we left C-10 was July the 26th, bound for C-9, tasked with digging mass-balance pits on the Matthes and Demorest glaciers. For all you glacial neophytes out there mass balance is the bread and butter of JIRP science. By digging a pit into the winter snowfall and comparing to the summer ablation (mass lost through melt, sublimation, calving, etc.) we can determine whether the glacier has gained or lost mass over the year, and learn about the variability of the glacier on an annual basis. JIRP holds one of the longest records of glacial mass balance data - having measured Taku Glacier mass balance every year since 1946.  Storglacieren in Sweden is the only glacier with a similarly long data set.

Our itinerary was a nine-mile ski to C-9, pausing to dig a pit just short of camp on the Matthes Glacier. We would spend the night in camp, and then ski down onto the upper Demorest Glacier to dig another test pit before returning to C-9 for the night. On our final day we were bound for C-18 and the wonders of the Vaughn Lewis Icefall and Gilkey Trench.

We waved our final goodbyes to C-10, made a final pit-stop into Dreamland, and then took off down the ski hill onto the vast expanses of the Taku. We skied up-glacier on snowmobile tracks laid down by Scott McGee and the survey team, taking a few short snack breaks along the way, eventually hanging a right up the Matthes Glacier towards C-9. The turn onto the Matthes meant that we were officially on ground that none of us – save for our friendly field staff members Annie Boucher and Matt Pickart – had ever tread upon before - uncharted territory. As we set a course for discovery, I couldn’t help but smile. The interface between the Taku and the Matthes is quite noticeable; as the Matthes spills out into the Taku the flow rates vary greatly, producing a crevasse ridden terrain. These are mostly ankle-biters and nothing to really worry about, mostly affecting scientific curiosity instead of trepidation or thoughts of roping up.

Mary Giannotti and Jon Doty relaxing while Matt Pickart and Chrissy McCabe dig. Photo by Annie Cantrell.

After about four or five hours of skiing through marginal weather, we reached the pit location, and began digging. We dig our mass balance pits in four steps, each reaching progressively deeper down through the snowpack.  The north facing wall is a clean wall, where we make measurements of density, and is never stepped upon as it would affect the snow density below.

At first everyone is at work shoveling out the initial meter of depth, but once the first step becomes defined, only one person can safely fit on each step. At that point, those inside of the pit begin to shovel from their step onto step one, from where it is a shorter shovel throw to remove the snow from the pit. Those who are not within the mass-balance pit take a break and refuel for their next shift inside, or tend the rim of the pit to prevent snow buildup. This year our pits have averaged 3.5 to 4 meters deep, which takes about 4 hours to dig – in the past, however, pits have ranged up to 8 meters in depth, requiring feats of strength that even the Dread Pirate Roberts would shy away from.

The treasure at the bottom of the pit? The annual layer. This line marks the boundary between this year and last year’s snowfall. It can be represented by a variety of features within the snowpack: an undulating ice layer - evidence of suncups from the previous year; a dirty layer – dust and debris upon the snowpack deposited throughout the summer and buried during the accumulation season; or depth hoar – large unconsolidated sugary snow crystals which sits upon the far more dense firn (year-old snow). Once we have found the annual layer we begin to take our data from the pit. We prep the wall of step four (the deepest) into a clean vertical face, and sample the snow at 10 cm (~4”) intervals using a coring device of known volume. Measuring the mass of these snow samples (and the thickness of all ice lenses that cut across our sampling section) gives us a density profile of the snowpack. With this knowledge, we can determine the water equivalent of the accumulated snow at this location on the glacier.  By digging pits at varying elevations and distances along the central profile of the glacier, we can estimate the total accumulation received by the glacier for the past year.

Our pit on the Matthes ended up being 4 meters deep. The depth of our pits creates an interesting logistical problem: how to sample snow cores and ice lenses at fifteen plus feet off the ground. We JIRPers take this as an opportunity to cross the disciplines of science and mountaineering, and so we build a snow anchor and collect data on rappel. In this metaphorical crow’s nest (I know, this likeness is a bit of a stretch) we have a bird’s eye view of the pit we have dug, and can sample the layers safely and precisely.

View of Camp 9, with Matthes Glacier in the background.  Photo by Annie Cantrell

Hungry from a full day’s work, we chugged on up the hill to C-9 through a whiteout, gaining the first views of our home for the next few days only once we were within thirty feet. We all piled inside, leaving our backpacks covered up outside on the nunatak as there was no room indoors for anything more than people. C-9 consists of a single two story building with exactly enough space for about two fewer people than we had in our crew. We managed to squeeze in, and bided our time reading graffiti on the wall and cracking jokes while we waited for the pasta water to boil. After dinner there was only one option: bed.

Interior of Camp 9 with Matt Pickart.  Photo by Annie Cantrell.

Dawn broke with a cloudless sky, and an absolutely beautiful view. After finishing off leftovers from last night we were treated to fresh oatmeal! Our ski down to the pit on the Demorest Glacier was an absolute treat – views of Devil's Paw, the Dipyramid, the Citadel, hanging glaciers, bergshrunds, and so much more. The first half of the ski was a long downhill, and so I sat back and paid zero attention to the track ahead of me as I soaked in the alpine panorama. Once we hit the Demorest Glacier we skied a few more miles of flats to reach the test pit. The sun was hot and bright, and so we blasted some music and got to work. The day was pleasant and the pit went quickly, and as manpower became less necessary within the pit we dug couches into the snow, and laid our socks on our ski poles to dry. Our pit ended up 4.5 meters deep, and so we cored it, and set sail back to C-9, treated to an absolutely incredible sunset just as we topped the camp ridge. Our rations for the night consisted of spaghetti with a mixture of tomato sauce, leftover broccoli cheddar soup, and roast beef for toppings. As we tucked in to bed, strong winds buffeted our home, but thoughts of the coming day’s traverse to C-18 and adding new points to my life’s map lulled me to sleep.

Matt Pickart, Lindsey Nicholson and Jon Doty watching the sunset with Devil’s Paw in the background. Photo by Salvador G. Candella.

The JIRP Spirit

By Muriel Will

[NOTE:  Muriel wrote this post at Camp 10 on July 25th (JIRPmas), but helicopter logistics have caused a delay in posting.  Our apologies for the delayed JIRPmas wishes!] 

T’was the day of JIRPmas, and all through the camp every JIRPer was stirring, why even the mouse. The snow pits were all dug by the students with care, while hopes of helicopters danced through our heads.  

Alexei Doncov, and Leah Nelson enjoying the afternoon sun on the Camp 10 deck with our JIRPmas ski tree. Photo by Muriel Will.

Greetings and salutations from Camp 10. Today (July 25th) is an honorary JIRP holiday, “JIRPmas”. We have all been busy on our breaks between lectures and field activities, making gifts to later exchange with our JIRP secret Santas.

Although relaxing days such as this are a great respite after long days of digging and skiing, the true spirit of our team (and the extravagance of the landscape where we find ourselves) is most memorable when down on the glacier. Of the 3 mass balance camping trips going out from Camp 10, I was able to attend the second.  For this trip, eleven students and four staff went up the Northwest Branch of the Taku Glacier with the intention of digging four mass balance pits. The first day (June 22nd) started off with some laughs and regretted goodbyes, as five of our visiting staff (including Alf and Stanley Pinchak, Jason Amundson, Bill Isherwood, and Jay Fleisher) departed our nunatak hideaway to return to their everyday lives.

After a three hour ski to our camp site, we split our strengths between: digging our first pit, setting up tents, and making our kitchen. A 4 inch ice layer approximately a foot down in the snow pack, provided a perfect floor for our kitchen, though a bit of an obstacle for our digging crew . On the second day we split up into two groups, with each of us debating which view we wanted to see most. The day could not be more ideal, with beach-worthy weather, we spent the day in shorts digging and chatting as we dug our pit of nearly 5 meters deep. However, that was before we realized we had dug almost half a meter beyond last year’s ablation layer (the previous summer’s buried surface). After a long day’s work we began our 2 hour ski back toward our temporary home, and at 21:30 we found ourselves in a sunset landscape that can only be described as unbelievable. Skiing over snow turned pink by the setting sun, towards a rainbow stretching clear across the sky, the beauty could only be made more remarkable by the fire in the clouds at our backs. Tired and wet from the rain now misting as we skied, we were greeted after a nearly 12 hour day, by the hoots and howls of the second digging team.  Our evening finished with a dinner of hot lentil stew, which the second team had prepared, but had refrained from eating until our much later return. The final pit of the trip was completed quickly, (July 24th) with all hands on deck, and although sad to leave our snowy getaway, a good dinner and dry feet were a welcome homecoming.


July 23, a fiery sunset that can never be truly captured by a picture, nor described in words. Photo by Muriel Will.

And so from Camp 10, merry JIRPmas to all.  May we all find the strength in our limbs, a fire in our hearts, and may we never take for granted the people and places we encounter along the way.

Spring Fieldwork - Taku Glacier 2013

By Chris McNeil 

During the first week of April 2013, Pat Dryer from University of Alaska Southeast, and Shad O’Neel and I from the US Geological Survey, flew to Camp-10 on the Juneau Icefield. We landed on the main trunk of Taku Glacier just below C-10 and unloaded our gear from the ski plane.  The engine started and the plane took off, leaving just the three of us among the vast expanse of the Taku. Slogging what gear we would need immediately, we skinned up the nunatak to the almost completely buried camp. We spent the following hours digging into various buildings of C-10, retrieving what supplies and items we would need for our research over the next few days.

 

The “Cookshack” at Camp-10 on the Juneau Icefield, after digging for quite some time to unbury it from meters of snow.  Photo:  C. McNeil

Our purpose for coming to C-10 so far removed from the normal field season of the Juneau Icefield Research Program (JIRP) is related to a project aimed at better understanding runoff into the Gulf of Alaska (GOA). The Taku River is a large contributor of fresh water to the GOA. Our task this spring was measuring snowfall at multiple glaciers around the GOA where we used high frequency ground penetrating radar (GPR) to determine winter snowfall.  Our aim is to connect the glacier mass balance with the hydrology, which carries nutrients to the ocean, drives the Alaska Coastal Current, and ultimately feeds the critters that we end up eating!

Pat Dryer tows the GPR in front of a snow covered Taku Range.  Photo:  C. McNeil

Over the next few days we collected GPR data along the main trunk of the Taku Glacier, including the historic survey line of “Profile 4” just in front of C-10. We also completed a snow pit at the long measured “Taku Glacier test pit #4”, a snow pit that has been dug in front of C-10 every summer by JIRP participants since the late 1940s.

 

Pat Dryer and Chris McNeil trying to stay out of the weather while drilling a snow core at Taku Glacier snow pit site #4.  Photo:  S. O'Neel

With a large storm system threatening to pin us in camp for what could have been a week, we had Coastal Helicopters pick us up. Touching down in Juneau, Shad and I soon hopped on a plane back to Anchorage, making the C-10 to Anchorage traverse in just 12 hours! Our nightly readings of the literature in the radio room at C-10 informed us that we were the first people doing fieldwork out of C-10 during April since 1966. As Shad and I are both JIRP alumni we were proud to be part of another milestone in JIRP history. Although we didn’t accomplish everything we hoped to, we got a good start on the project. When combined with all the other field data collected this spring, the Taku data will help to fill a big gap in snowfall measurements around the state.  In future trips we will continue accumulation measurements and place ablation wires along the centerline of the ablation zone of the Taku.  The data collected this spring and in future trips will supplement measurements made by JIRP participants and also be a large part of my graduate thesis.

[EDITOR'S NOTE:  Chris McNeil and Dr. Shad O'Neel are multi-year JIRP participants, with their first JIRP field seasons in 2009 and 1996 respectively.  The Foundation for Glacier and Environmental Research (FGER, JIRP parent organization) is excited to continue and expand research partnerships with affiliated and external researchers.  Thank you, Chris!]