From Deep Crust to Landslide – Structural Controls on Slope Instability in Western Norway 

Western Norway is a geologically complex region where deep-seated crustal structures—Caledonian shear zones, detachment faults, and Proterozoic basement fabrics—intersect with active geohazard processes. Inherited structures like bedding, joints, faults, foliation, folds and weak rocks control many slope instabilities (e.g., Agliardi et al., 2001; Brideau et al., 2009). Consistent with this principle, numerous large rockslides or risk sites in the region (e.g., Åknes and Hegguraksla in the Storfjord area, Tafjord, Loen) occur along or adjacent to pre-existing bedrock structures, yet the causal link between crustal architecture and slope-scale failure mechanisms remains poorly constrained.

Supervisors

Main supervisor: Carolina Cavalcante, UiB-GEO
Co-supervisor: Mathilde Sørensen, UiB-GEO

Project description

This project integrates geological mapping, structural analysis of shear zones, fractures and faults, and landslide inventory (NGU, EPOS-NO, historical events) to evaluate how inherited crustal structures control the slope susceptibility to rockslide. 

The chosen study area is Fykse, located on the eastern side of the Fyksesund Bridge (W Norway) within the context of the Caledonian nappes. In this area, the Caledonian Upper Allochthonous oceanic units are in tectonic contact against the continental upper Bergsdalen Nappe. The study area hosts a post-glacial landslide that seems to be related to mica-rich gneiss and marble of the Upper Bergsdalen Nappe together with joints and faults. Together, rock rheology and structural features seem to be the most important factors controlling the Fykse landslide that occurred approximately 11,000 years ago (Helle, 2008). The landslide involved a volume of 10 million m³ (Aarseth, I. 2025), and its crown is situated at about 480 m above the slide deposit.  

The student will first acquire landslide occurrence data from the NVE website and compile existing geological maps (NGU) for the Fykse area. Because the landslide occurred approximately 11,000 years ago, the original crown and scarps are no longer clearly visible due to post-glacial weathering, vegetation cover, and modern infrastructure (houses, roads). Therefore, rather than mapping fresh geomorphic features, the student will adopt a relict-structure approach: using high-resolution digital elevation models (DEMs) and LiDAR-derived hillshade images to identify subtle, relict lineaments and slope breaks that likely correspond to the original landslide crown, main scarp, and lateral margins. These interpreted features will be will be assessed through direct field observations during two field campaigns (5–10 days each) through targeted inspection of bedrock exposures along inferred scarp positions, measuring foliation, joints, faults, and fracture density in accessible outcrops. The student will then perform stereonet and spatial analysis (dip/dip direction rose diagrams, contour plots) to test whether the orientation of inherited structures correlates with the interpreted landslide boundaries. By combining structural geology, relict landslide mapping, and GIS-based inventory analysis, the student will deliver a process-based model explaining how crustal-scale anisotropies localized the Fykse landslide despite 11,000 years of degradation, and more broadly, how such approaches can inform rockslide susceptibility in similar geological settings across Western Norway. 

The project is suitable for students holding a Bachelor's degree in Geology or Geophysics. Potential candidates should have taken and passed the following courses (or their equivalents): GEOV104-Introduction to Structural Geology and Tectonics

Overview photo of the study area, Fykse. Green hills and large bourlders in the fields. Houses can be seen in the background.
Overview photo of Fykse, where field work will take place. Photo: https://kringom.no/en/hardanger-og-voss/kvam/fykse (external link)

References:

  • Aarseth, I. 2025. Kringon, a gate to Vestland. Fykse | Kringom 
  • Agliardi, F., Crosta, G. & Zanchi, A. 2001. Structural constraints on deep-seated slope deformation kinematics. Engineering Geology, 59, 83–102. 
  • Brideau, M.-A., Yan, M. & Stead, D. 2009. The role of tectonic damage and brittle rock fracture in the development of large rock slope failure. Geomorphology, 103, 30 – 49. 
  • Helle, S.K. 2008. Early post-deglaciation shorelines and se-level changes along Hardangerfjorden and adjacent fjord areas, W Norway. Doktoravhandling. Bergen. University of Bergen. 

Proposed course plan

Last updated: 23.06.2026