Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Geographisches Institut » Physische Geographie » Prof. Dr. Markus Egli » Egli

Completed research project

Title / Titel Influence of permafrost on chemical and physical weathering
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung With increasing temperatures, permafrost is continuously thawing. This will lead in future to different thermal and hydrological conditions in the soil and regolith in cold regions. Therefore, climate change is assumed to cause a marked change in weathering conditions in high Alpine areas. Long-term chemical weathering and physical erosion rates are interrelated processes. In order to better understand landscape response to climate change, it is important to quantify both processes. The planned investigations generally aim at the estimate of element denudation/weathering rates and short- and long-term erosion of high Swiss Alpine soils (Upper Engadine: Albula and Val Bever). Both types of sites will be considered: a) with and b) without permafrost. The main objectives include
1) the evaluation of chemical weathering mechanisms using tracers such as immobile elements and Sr-isotopes
2) the determination of soil erosion rates (long-term) using two different techniques: a) in situ produced cosmogenic 10Be in soil sections and b) the inventory of meteoric 10Be in soils. Short-term erosion rates will be estimated using 137Cs as tracer.
3) determination of organic matter stocks in soil and characterisation and 14C dating of labile and stable (resistant to a H2O2 treatment) organic matter fractions.
4) Mapping of present day permafrost distribution and monitoring of near-surface and ground surface temperatures is essential for the understanding and prediction of the weathering behaviour of high Alpine regions.
An important and innovative aspect is that chemical weathering and particularly erosion rates will be characterised using a multi-method approach. A cross-check of all the methods used will allow an extended interpretation and mutual control of the results. Furthermore, novel or very recently developed methods (erosion rates determined by meteoric 10Be using a non-steady-state approach; spatial on-site detection and characterisation of permafrost using a highly novel 3-D geophysical approach, 14C dating of stable (H2O2-resistant) soil organic matter, etc.) will be applied for the first time in high Alpine regions. The expected new insights will lead to a better understanding of the processes of high mountain soils and are a further step towards improving climate-related modelling of fast warming scenarios and increasing system disequilibria.
Keywords / Suchbegriffe erosion, weathering, 10Be, 137Cs, geomorphology
Project leadership and contacts /
Projektleitung und Kontakte
Prof Markus Egli, PhD (Project Leader)
PD Susan Ivy Ochs, PhD
PD Christof Kneisel, PhD
Prof Chrsitine Alewell, PhD
Funding source(s) /
Unterstützt durch
SNF (Personen- und Projektförderung), Other Public Sources (e.g. Federal or Cantonal Agencies)
In collaboration with /
In Zusammenarbeit mit
Laboratory of Ion Beam Physics, ETHZ Switzerland
Dept. Geography, Univ. of Würzburg Germany
Institute of Environmental Geosciences, Univ. of Basel Switzerland
Duration of Project / Projektdauer Sep 2011 to Aug 2015