Can we distinguish meteorological conditions associated with rockfall activity using dendrochronological analysis? - An example from the Tatra Mountains (Southern Poland)

Improved tree-ring sampling strategy enhances the detection of key meteorological drivers of rockfall activity

“…On forested slopes, growth disturbances in trees are reliable ecological indicators of past rockfall activity and fluctuations thereof over decadal to centennial timescales (Alestalo, 1971;Stoffel et al, 2010;Bollati et al, 2018). Yet, apart from Perret et al (2006), Šilhán et al (2011), Zielonka and Wronska-Walach (2019) and , reconstructed time series of rockfall were only rarely compared to instrumental data with the aim to detect meteorological drivers of process activity and fluctuations in activity. This lack of dendrogeomorphic studies looking at actual drivers of rockfall activity is attributed (1) to the presence of non-climatic trends in reconstructions that can be intrinsic to the dendrogeomorphic approach and (2) to the absence of clear guidelines regarding sampling design that would allow obtaining robust relations between rockfall activity reconstructed from tree rings and the assessment of meteorological drivers of activity.…”

“…In that sense, our results differ from the other climate-rockfall assessments based on dendrogeomorphic reconstructions (Perret et al, 2006;Šilhán et al, 2011) and, in more general terms, from a large body of monitoring literature demonstrating that thermal conditions and especially freeze-thaw cycles would control rockfall frequency in mountainous regions (Matsuoka and Sakai, 1999;Frayssines and Hantz, 2006;D'Amato et al, 2016;Matsuoka, 2019). Several hypotheses may explain the absence of relationships between rockfall activity and thermal variables at Saint Guillaume, such as (1) the resolution of the dendrogeomorphic records which only partly represent rockfall activity and probably do not include high-frequency-low-magnitude events; (2) the complex influence of freeze-thaw cycles on rockfall activity, with events occurring more frequently during warming and thawing than during cooling periods (D'Amato et al, 2016) and under moisture-saturated freeze-thaw conditions (Krautblatter and Moser, 2009); or (3) the use of the SAFRAN re-analysis dataset which does not reflect microclimatic variations and effects related to microtopography of cliffs (Matsuoka and Sakai, 1999;Schneuwly and Stoffel, 2008b;Matsuoka, 2019;Zielonka and Wronska-Walach, 2019).…”

“…Paradoxically, whereas tree-ring series have been used extensively to quantify rockfall frequency variations over time, dendrogeomorphic studies have only rarely attemptedwith the exception of , Šilhán et al (2011), Zielonka and Wronska-Walach (2019) and Mainieri et al (2020) to identify drivers or to correlate changes in rockfall frequency with changing weather conditions. This scarcity of analyses on rockfall drivers is explained partly by the absence of clear guidelines regarding the sampling strategy required to obtain reliable chronologies that can be used for comparison with meteorological time series.…”

Współczesna ewolucja rzeźby Tatr

“…2017, Kłapyta i in. 2016, Zielonka, Wrońska-Wałach 2019. Charakterystyka ilościowa procesów sekularnych przedstawiona jest w tabeli 1.…”

Experimental field study on the fatigue and failure mechanisms of coastal chalk cliffs: Implementation of a multi-parameter monitoring system (Sainte-Marguerite-sur-Mer, France)

“…In coastal cliff environments, these external factors can include subaerialincluding subsurfaceagents (e.g., precipitation (Duperret et al, 2002;Brooks et al, 2012;Bernatchez et al, 2021;Young et al, 2021), water table fluctuations (Hutchinson, 1969;Lageat et al, 2006;Pierre and Lahousse, 2006), variations in temperature (Bernatchez et al, 2011(Bernatchez et al, , 2021Letortu et al, 2015a)), marine actions (e.g., mean sea-level variations, tide, sea state (Guilcher, 1954;Robinson, 1977;Sunamura, 1977;Carter and Guy, 1988)) and anthropogenic phenomena (e.g., coastal defence structures that modify sediment transport (Costa et al, 2004)). In other environments, such as glacial and mountain regions, monitoring projects have identified the influence of rainfall (e.g., Rapp, 1960;André, 1997;Ilinca, 2009;Zielonka and Wrońska-Wałach, 2019;Mainieri et al, 2020), snowmelt (Reid et al, 1988), freeze-thaw cycles (e.g. Wieczorek and Jäger, 1996;Matsuoka and Sakai, 1999;Ilinca, 2009) and solar heating (Collins and Stock, 2016), to be the main triggering mechanisms for rock fall activity.…”