News from Germany 2001

Germany
published in FROZEN GROUND,
the News Bulletin of the International Permafrost Association (IPA),
Number 25, December 2001

The joint-project of the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, and the Centre d'Ètudes Nordiques, Université Laval, Québec, for the investigation of permafrost development in emerged marine sediments near the eastern shore of the Hudson Bay continues into its second year. The monitoring of the subsurface temperature field of a (mineral) palsa east of Umiujaq, Nunavik shows a mean annual temperature of -0.6°C. A pressure transducer positioned near the bottom of the palsa (at the freezing front) provides us with a continuous 1-year record of the pore pressure indicating a strong hydraulic gradient into the palsa. The development of a numerical model to simulate the thermal processes throughout the year within the palsa is in progress. Since the frozen core of the structure is rather close to the melting point of ice, we consider this site as a unique opportunity to observe the progress of climatic change in the Arctic. Therefore, we have plans to extend the monitoring operation beyond 2003 (Georg Delisle).
The Potsdam Research Unit of the Alfred Wegener Institute for Polar and Marine Research (Hans-W. Hubberten) co-ordinates the multidisciplinary terrestrial part of the joint German-Russian project "System Laptev Sea 2000". An expedition to the Lena Delta took place in July and August 2001 (Expedition leaders: Eva-Maria Pfeiffer and Mikhail N. Grigoriev), consisting of 8 German and 8 Russian scientists and technicians from Moscow, St. Petersburg, Yakutsk and Tiksi. Team 1 focused on modern processes in permafrost soils and the underlying frozen sequences and used a biological station of the Lena Delta Reserve on Samoylov Island in the central part of the Lena Delta as a research base. At four measuring sites installed in 1998, the energy and water balances of the active layer are registered year round. During the field season the pedogenic and soil microbial parameters, which control the production, oxidation and emission rates of trace gases, were studied as well as the carbon flux (CH4, CO2). The emission of CH4 and CO2 from other possible sources, such as lakes and ice complex deposits, has been studied. Surprisingly high methane emissions have been observed from the frozen soil as well as from the ice wedge part of the ice complex. Several cores were drilled down to 8.5 m into the permafrost, which will mainly be used for microbial and molecular biological investigations.
Under the umbrella of the IPA-IASC project ACD (Arctic Coastal Dynamics, Project leader: Volker Rachold, Team 2 concentrated on the study of the coastal dynamics at the west coast of the Lena Delta using a field camp at Babaryna Island. After investigating the coastal processes at the eastern and western coasts of the Laptev Sea in 1999 and 2000, three weeks were dedicated to study the complex system of the coast of the sandy Arga Complex, which is separated from the open ocean by shallow lagoons and tens of kilometers long north-south tending sand barriers. An unexpected result was the importance or even dominance of wind erosion and accumulation compared to wave action. Apart from geodetic measurements to compare the actual coastline with older air photos in order to determine the coastal retreat rate, shore face profiles were measured from the barriers to the 10 m isobath and sediment samples were taken. Some results of this project are shown in 14 articles actually in press in a special volume of the journal "Polarforschung" which will be printed at the beginning of next year. A small group from AWI carried out geocryological studies in Central Yakutia between the middle Lena and the Aldan rivers in cooperation with the Permafrost Institute, Yakutsk.

The Department of Physical Geography, University of Trier (Christof Kneisel) has continued the investigation of a mountain permafrost occurrence below the timberline in the Upper Engadine, eastern Swiss Alps. Geophysical measurements were carried out and monitoring of ground temperature is now maintained for the third year to study the physical processes controlling the interaction of permafrost with the environment at this sporadic permafrost site. The measurement of the the near surface ground temperature is extended along altidudinal belts from the subalpine zone to the periglacial/subnival zone.

After completion of the PACE project the Giessen PACE group (Lorenz King) continues mountain permafrost research in the Mattertal, Valais, Swiss Alps. Temperature data of the borehole Stockhornplateau (3410 m) near Zermatt indicate a permafrost thickness of about 160 m and an active layer thickness of about 2 m. Deepest ground temperatures of -2.6°C were reached in a depth of 22.5 meters. Further ground temperature measurements have been started at the lower end of the discontinuous permafrost belt in the Gornergrat area above Zermatt. The data will contribute to the programme of Thomas Herz concerning the influence of a coarse-grained debris cover on energy transfer processes between atmosphere and lithosphere and ground temperatures in the alpine periglacial belt. At the end of September, the test area Grächen-Seetalhorn will be instrumented with a 30 m borehole and a meteorological station.

Mountain permafrost investigations are also carried out in the neighbouring Turtmann valley, Valais, Switzerland by a research group of the Department of Geography at the University of Bonn (Richard Dikau). The valley is characterized by a high density of rock glaciers at all stages of activity. A main objective of the project is the scale dependent significance of rock glaciers to determine the sensitivity of high mountain geosystems to global environmental change. Through the combination of different approaches and methods in various spatial and temporal scales a holistic approach is to be achieved. A sediment budget for the catchment may support the hypothesis that the rock glacier process is the dominant sediment flux in alpine regions during the Holocene. A monitoring programme was started in 1990 with the following objectives: Reconstructing past and present permafrost distribution (Dikau, Nyenhuis, von Witsch), rock glacier distribution (Nyenhuis), geophysical methods (Nyenhuis, Pfeffer), rock glacier movement rates applying remote sensing and terrestrial surveying (Roer, von Elverfeldt), rock glacier movement pattern modelling by process based models (Hoffmann), bioindication of rock glacier systems (Roer), periglacial system components and their coupling/decoupling with the glacial situation (Otto), quantifying sediment storages (Knopp, Nyenhuis), surface analysis by remote sensing (Schreiner), morphometric landscape analyses (Rasemann).