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Projects and ongoing research


  • Geomorphic and hydrologic implications of permafrost degradation in the Alps (GeoHype)
    Project Manager
    Blöthe J, Kraushaar S
    Start/End of Project
    01.06.2018 until 01.06.2020
    Description
    High-mountain environments are highly sensitive towards a warming climate, which is dramatically reflected by the shrinkage of alpine glaciers. With more and more glaciers disappearing, attention has moved towards the hydrological importance of ice stored in the periglacial environment, projected to exceed glacier ice volume in the European Alps by the mid-21st century. However, surprisingly little is known about the current state of the ice stored in the periglacial zones of alpine landscapes. Our project aims to disentangle the contribution of active layer and permafrost body to the summer runoff from the upper Kaiserberg catchment in the Austrian Alps. To achieve this goal, we combine repeated electrical resistivity tomography (ERT) surveys on the Kaiserberg rock glacier with continuous discharge measurements from two hydrological stations that we installed in the basin. We further collect water samples over the course of the summer that are analysed for δ18O and δ2H isotopes and the radio nuclide 129I , that allow us to differentiate thawing permafrost from active-layer or precipitation derived discharge.
    Financing
    Dr. Hohmann Förderung der Gesellschaft für Erdkunde zu Köln; Hanna Bremer Stiftung
    Publications
    Journal Articles
  • Suspended sediment transport in German lowland rivers (in cooperation with BFG)
    Project Manager
    Hoffmann Th, Blöthe J
    Start/End of Project
    since 01.10.2017 (unlimited)
    Description
    Suspended sediment load dominates the sediment export from most lowland rivers around the world, also constituting a significant transport medium for pollutants and contaminants. This has important implications for the management of river systems that aims at achieving a good ecological and chemical status, as required for instance by the European Water Frame directive. A thorough understanding of the sources, transport mechanisms and sinks of suspended sediment is therefore a crucial prerequisite for successful management. However, sources and sinks of suspended sediment and the resulting concentration in the river water are highly variable throughout the year and in between years. In this project, we are interested in the spatiotemporal variability of suspended sediment transport in major German lowland rivers. In a first publication, we find that distinct breaks in the scaling relationship between suspended sediment concentration and discharge are induced by the organic matter concentration
    Contact Person
    Hoffmann Th
    Publications
    Journal Articles
    • Hoffmann T O, Baulig Y, Fischer H, Blöthe J H: Scale-breaks of suspended sediment rating in large rivers in Germany induced by organic matter Earth Surface Dynamics, 2020: https://doi.org/10.5194/esurf-2020-3
  • Outsize fan evolution in the upper Rhone valley, Switzerland
    Project Manager
    Schrott L, Blöthe J
    Start/End of Project
    01.08.2016 until 01.08.2018
    Description
    In the Upper Rhone Valley, Switzerland, three very large fan systems (footprint area ~1 km2 each) are fed by catchments of just about similar size. It remains largely unresolved if these so called outsize fans evolve as the result of high-frequency or high-magnitude processes? Especially in the European Alps, where slopes adjust to postglacial conditions, this question has important implications for natural hazard assessment and for understanding postglacial landscape development. Grounding on three different methods, geomorphometric analysis of high-resolution digital topography, ground penetrating radar surveys, and surface exposure dating using cosmogenic radionuclides, we seek to analyze 1) the morphology of the fans and its feeder basins, 2) the sedimentary facies and architecture of the deposits, and 3) the chronology of the events that lead to the formation of the fans
  • Rock glacier permafrost in the Central Andes of Argentina (PermArg): regional distribution – ice content – hydrological significance
    Project Manager
    Schrott L, Blöthe J
    Start/End of Project
    01.01.2015 until 01.01.2019
    Description
    Rock glaciers are the predominant periglacial landform in the Central Andes. Within the permafrost body and the seasonally frozen active layer, rock glaciers potentially store large amounts of water. As opposed to ice glaciers, it remains largely unclear how the dynamics of these water reservoirs affect the hydrology of these regions. Due to their large abundance in this part of the Andes, the hydrological significance of rock glaciers has triggered a strong scientific debate. Therefore local studies assessing water storage capacities of rock glaciers are urgently needed The Central Andes of Argentina between 30 and 33°S represent an ideal location to close this research gap, because the study area features probably the highest rock glacier concentration in the world, the agriculture critically depends on melt water, and “Morenas Coloradas” and “Dos Lenguas” rock glaciers have been subject of previous permafrost investigations. The aims of the proposed research project are (i) to determine how climate, topography and lithology control the spatial distribution of rock glaciers in the Central Andes of Argentina between 30 and 33°S; (ii) to quantify seasonally stored and released water equivalents from active layer sediments as well as ice contents of permafrost bodies in two local rock glaciers; and (iii) to estimate water storage capacities of rock glacier permafrost in the whole study area. To achieve these objectives we will use a combination of field geophysics (electrical resistivity tomography (ERT), refraction seismic tomography (RST), ground penetrating radar (GPR)) and four phase modeling to estimate the volumetric ice contents of the active layer and the permafrost bodies of the “Morenas Coloradas” and “Dos Lenguas” rock glaciers. Local investigations will be complemented by direct observations of sediment properties, thermal monitoring and field based mapping. Regional controls of the rock glacier distribution will be investigated by compiling and analyzing a remote sensing based inventory that further serves as basis for a first order quantification of the water storage capacities of rock glaciers based on empirical field data. This enables us to draw quantitative conclusions on the hydrological significance of Andean rock glacier permafrost.
    Financing
    Deutsche Forschungsgemeinschaft
    Publications
    Journal Articles
    • Halla C, Blöthe J H, Trombotto D, Schrott L: Permafrost in Argentiniens Anden - eine bedeutende hydrologische Ressource Geographische Rundschau, 2018; 70: 36-40