SP3.3: Mass movement assessment and modelling in recent ice-free areas

Subproject 3.3

Mass movement assessment and modelling in recent ice-free areas

The retreat of glacier ice fundamentally changes stability of the surrounding rock and debris slopes due to the massive thermal, mechanical and hydrological change initiating massive creep and rock slope failures (Haeberli et al., 2010). Alpine and arctic polythermal glaciers develop permafrost below the upper cold-based glaciers and unfrozen rock below the warm based lower glacier parts. Glacier retreat and warming cause high rates of permafrost degradation and sometimes aggradation, sudden changes in hydro- and cryostatic pressures and fast changes in lateral ice-stresses on slopes (Krautblatter & Leith, 2015).

In SP3.3, we will develop generic mechanical models that undergo rapid thermal, mechanical and hydrological change. Release of ice stress and thermal conditions will be refined by additional information on glacier retreat (SP2.1) and on simulated basal ice temperatures (SP3.2). For the latter temperatures, SP3.3 will build on the finite-element Elmer/Ice applications calibrated to the benchmark glaciers for the last decades (SP3.2). Here, these simulations will be extended to cover the last century.

The presumable starting date is the end of the Little Ice Age (LIA). The modelling strategy is an initial equilibration run under LIA conditions followed by a forward simulation to present day forced by climatic data (e.g. ERA-20C, ERA5, CORDEX-CORE) downscaled to local AWS measurements (joint effort with SP3.1).
The centennial scope assures that the long-term memory is imprinted in the 3D temperature field. Accounting for both retreat and temperature information, we will develop generic rock-ice-mechanical models using the benchmark sites Vernagtferner and Hintereisferner.
The benchmark model will apply temperature-dependent changes in rock stability, ice stability in fractures and rock-ice interfaces as well as changes in hydro- and cryostatic forcing and lateral destabilisation due to reducing glacier support (Krautblatter et al. 2013).
Model development will occur on basis of discontinuum mechanical (UDEC) models that have been developed in recent research projects (Mamot et al., 2020). The generic mechanical models will be clustered to specific conditions indicated by glacier retreat and elevation change information outside glaciers to constrain models that anticipate the propensity of major hazards due to rock slope and debris slope failures in the recently ice-free slope and glacier forefields.

 

For specific information on the sub-project please contact: Prof. Dr. Michael Krautblatter, Ingenieurfakultät Bau, Geo & Umwelt, Arcisstr. 21, 80333 Munich, T: 089-289-25866, m.krautblatter@tum.de, http://www.landslides.geo.tum.de

Co-PIs: J. Fürst (FAU Geography), B. Etzelmüller, S. Westermann (Univ. Oslo)


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Felix Pfluger

Felix Pfluger

felix.pfluger@tum.de

I am Felix. My research focuses on understanding the interaction between glaciers and permafrost in alpine environments. During paraglacial transition phases, as the landscape changes from ice to ice-free states, geomorphic activity is higher than usual. The relatively rapid and drastic change in thermal and hydrological characteristics predisposes rock slopes to a more fragile state. Furthermore, the evolution of permafrost in space is critical for the assessment of rock slope stability and potential hazards.

 

My aim is to develop a rock-ice mechanical model suitable to predict rock mass failure concomitant with changing cryospheric conditions. Besides rock mechanical laboratory experiments I will take advantage of the capabilities of the MOCCA group by having a joint field campaign using geophysics to explore glacial and permafrost conditions at a study site in Kaunertal. The knowledge of seismic, geoelectric and radar measurements will complement the permanent temperature monitoring of rock surface temperature to gain insights into the thermal characteristics at the study site. By coupling the mechanical model to a dynamic thermal model, we will be able to assess and predict rock mass failures in time.

 

Besides scientific goals you can hang out with me to blues rock music, even better to play some music together, to do some rock climbing or go fishing. As growing up in the Alps I am happy to work on a local study site in my home region.