The objective of this project is to date paraglacial rock-slope failures in the north-western part of Iceland (Westfjords) with a geomorphological approach, combining relative dating procedures. The temporal scale considered includes the whole deglaciation period, i.e. the last 15,000 years. Field investigations are selected in the Westfjords, in North-West Iceland, where landslide bodies are numerous, and 186 of them have been already mapped during a preliminary research (Peras et al. 2016).
We combine the use several approaches:
(i) geomorphic analyses (landform mapping and geomorphological stacking; e.g. dated raised beaches covered with landslide deposits), (ii) deposit relative dating through stratigraphy, radiocarbon and tephrochronology analyses.
The two approaches were already applied in Iceland and gave new results with absolute and relative ages for seventeen landslides published in recent high level and international literature by the PI of the PARI project and the team involved (Mercier et al., 2013, 2017; Coquin et al., 2015, 2016, 2019; Cossart et al., 2013, 2014, 2017; Feuillet et al., 2014; Decaulne et al., 2016; Peras et al., 2016). Nevertheless, none of the Westfjords landslides are dated so far; that’s a gap we have identified and propose to fill.
The expected results are:
(i) New insights for landslides chronology in the Icelandic Westfjords based on relative and absolute procedures. Such new results will procure benchmarks regarding deglaciation in NW Iceland, where the documentation in the international literature is lacking. Those results will represent the first application of these chronology methods on landslides in this area of Iceland and will be published in high impact peer review journals (e.g. Quaternary Science Reviews, IF: 4.112). (ii) The impact of deglaciation on the evolution of landscapes and landforms. The contribution of glacial debuttressing and landsliding to glacial troughs development as cirques and U-shaped valley will be a significant new input to explain the excavation of so-called “glacial” landforms. These results will be published in high impact peer review journals, e.g., Earth Surface Processes and Landforms (IF: 3.694) or Geomorphology (IF: 4.139).