AMONG THE MUSK OX AT 74°30'N, 21°00'W
Field blog by Stefanie Härtel from Zackenberg, NE-Greenland
I write out of a Twin Otter, we just left behind the beautiful coast of East Greenland on our way back to Iceland. I return from three intensive weeks of fieldwork for my PhD study where I am investigating and comparing the geomorphology and geocryology of two High-Arctic periglacial landscapes in Svalbard and NE-Greenland. I feel tired but at the same time extremely happy about the data and observations I was able to collect.
During the first week, I investigated Zackenberg valley on my own whereas the last two week I participated in a PhD course entitled AG 833 "High-Arctic Permafrost landscape dynamics in Svalbard and NE-Greenland". This Perma-Nordnet field course, organised by Hanne H. Christiansen (UNIS) and Bo Elberling (CENPERM), was designed to link our understanding of periglacial processes and landscape history with carbon and nitrogen dynamics, and particularly to support PhD students tackling these questions in their PhD projects.
HIKING AMONG THE MUSK OX
My aim this year was to ground-truth a preliminary geomorphological map I developed based on aerial images (and after we had drilled our up to 21 m deep permafrost cores with the "Betty" drill rig last summer). So weaponed with GPS, note book, camera, active layer probe, foldable shovel and protective gear with rifle, signal pistol, radio and loooots of food I headed out to study the landforms and processes, and to compare it with my map. I hiked more than 160 km (in new hiking boots and without blisters!) collected about 20000 waypoints (e.g. to mark terrace edges, lobes, exposures and other observations...) and covered the mapping area quiet well though if you start to understand something you wish to stay for four seasons! I learned that my interpretation of the lowlands was pretty good but reality deviated on the slopes. In particular the eastern, gentler slope of Zackenberg valley shows a surface mosaic formed by a set of processes from solifluction, nival and fluvial processes to mass movements. I assume they are related to the differences in lithology (e.g. thickness of the till cover) and to meso-scale topography affecting the distribution of snowpatches, meltwater availablity and freeze-thaw dynamics.
I also studied natural exposures – and one fascinated me in particular but broke my heart at the same time: I found an impressive and active 24 km2 large retrogressive thaw slump which had a size of only 2 km2 in the year 2000.
The slump, located at 300 m asl, exposed bluish massive ice, layered and with clasts and fines incorporated but somewhat different to the segregated ground ice I had seen before in permafrost cores - so was that potentially buried glacier ice I had found there? To my misfortune, the slump is located in “area 1b”, a protected reference area where access is restricted and any kind of manipulation (including sampling) is strictly forbidden. Although I wrote a special research application to the scientific board of the station it was rejected and neither sampling of the thawing ground ice nor of the down-sliding sediment was permitted. I was able to map the slide using a dgps, at least something, but a bitter feeling is left - and anger.
AG 833 BEGINS - AND I GET A NEW PERSPECTIVE!
AG 833 brought together ten young researchers from the Universities of Oslo, Svalbard, Oulo and Copenhagen thanks to financial support by NORDEN which is part of the "Nordic Ministerial Council" Arctic collaboration program in Norway, by UNIS, the University Centre in Svalbard in Norway, and by CENPERM, the Center for Permafrost at the University of Copenhagen in Denmark.
Divided into two groups, we each investigated a northern and southern stretch from 400 m asl down to the coast. Our field part of the course included detailed mapping of the landforms, active layer probing, pit and exposure studies with soil sampling, and permafrost drilling along a transect from 200m to the delta.
In total, our group drilled at six sites and about 12 m of core and we studied about 10 exposure sections! The good but at the same time a challenge was the given free hand to the group on deciding where to focus and how to divide the work. Irregardless, I am so glad about the new perspectives on "what’s going on here and how can we find out about it" I gained by learning from my group fellows Wesley Farnthworth (UNIS), Niels Weiss (University of Stockholm/Page21) Kjersti Gisnås (University of Oslo), Mette Bendixen (University of Copenhagen) and from Graham Gilbert (UNIS).I learned to listen, to argue and to reconsider my concept. That was valuable!
EXCURSION TO NEVER-STUDIED-LAND AND WEATHER HAZARDS!
Have you ever been to a place that has basically never been studied before? On Earth? It might be we have been there. We sailed two hours to a magic place called Revet on Clavering Ø for a two days excursion, a site where a large delta spreads out into a wide fjord and almost "kisses" the other shore. Dryer, more continental, we can observe the consequences of a climatic gradient towards the inland ice. We were asked: what do you see? Where would you start to study? This trip was not only beautiful, it was inspiring and I felt reverently against my own profession
Back to the station we continued working hard and the weather continued to get worse. Snow storms, rainy windy days, fog and wind like h*** (up to 20 m/s) forced us to make smart decisions on how to spend our valuable time. I decided to start hiking at 4 in the morning one day when it was calm, which was ultimately a good idea though I got stuck in meters of snow at higher elevation where I had planned to go...
But in turn, we performed the entire core processing in the lab from core cutting, scraping, photographing, subsampling, excess ice determination, gravimetric ice content and subsampling for dating, LOI and texture and the cryo-litho stratigraphic description of our cores. Another challenge was our limitation to 26 beakers and to share the lab with the second group. But we made it! And we discovered extremely ice-rich permafrost in all five cores from the slope and valley bottom in contrast to the one ice-poor permafrost core at the coast. As next step we will carefully analyze our field data and also study monitoring data (climate, thermal regime, CALM etc.) both from Svalbard and Zackenberg. Finally, we compare the landscape dynamics at the two locations which are located close and are geologically similar but affected by a very different climatic regime.
The AG 833 course offers me valuable data for my PhD project such as input to my geomorphological and geocryological map. The number of questions has grown and they have become more precise.
Therefore, I kindly thank all participants of AG833 for their hard fieldwork and fruitful discussions, the Geo- and Biobasis staff and Zackenberg logistics for their support and of course Hanne and Bo who made this course happen!
PhD student at CENPERM and UNIS
Page21 project WP2