Efficiency of frost-cracking processes through space and time: An example from the eastern Italian Alps S. Savi a, ⁎, R. Delunel b , F. Schlunegger b a University of Potsdam, Germany b University of Bern, Switzerland abstract article info Article history: Received 15 September 2014 Received in revised form 13 January 2015 Accepted 15 January 2015 Available online xxxx Keywords: Frost-cracking Sediment production Sediment supply Spatial and temporal denudation rate Climatic variations Holocene It is widely accepted that climate has a strong impact and exerts important feedbacks on erosional processes and sediment transport mechanisms. However, the extent at which climate influences erosion is still a matter of de- bate. In this paper we test whether frost-cracking processes and related temperature variations can influence the sediment production and surface erosion in a small catchment situated in the eastern Italian Alps. To this extent, we first present a geomorphic map of the region that we complement with published 10 Be-based denudation rates. We then apply a preexisting heat-flow model in order to analyze the variations of the frost-cracking inten- sity (FCI) in the study area, which could have controlled the sediment production in the basin. Finally, we compare the model results with the pattern of denudation rates and Quaternary deposits in the geomorphic map. The model results, combined with field observations, mapping, and quantitative geomorphic analyses, reveal that frost-cracking processes have had a primary role in the production of sediment where the intensity of sediment supply has been dictated and limited by the combined effect of temperature variations and conditions of bedrock preservation. These results highlight the importance of a yet poorly understood process for the production of sediment in mountain areas. © 2015 Elsevier B.V. All rights reserved. 1. Introduction During the past two decades, the extent at which climate influences erosion and limits the height of mountain ranges has been discussed in a controversial way, highlighting the difficulties in discriminating the effects of climate versus tectonic on denudation rates (Molnar and England, 1990; Raymo and Ruddiman, 1992; Egholm et al., 2009; Koppes and Montgomery, 2009; Thomson et al., 2010; Willenbring and von Blanckenburg, 2010; Egholm, 2013; Herman et al., 2013). More recently, the development of in situ produced, cosmogenic- nuclide techniques has allowed a substantial enrichment of data quantifying denudation rates in different regions of the world and on multisecular to millennial time scales. Still, denudation rate values measured through cosmogenic nuclides include the effects of a series of processes (e.g., physical and chemical weathering, sediment produc- tion, etc.) and conditions (e.g., hillslope-channel connectivity, transport capability of streams and rivers, etc.), which could be difficult to disentangle from each other but which influence the landscape's response to environmental changes (Harvey, 2002). This is particularly the case for cold regions and mountain areas not glaciated nowadays, where periglacial processes including frost-cracking have been proposed as a very efficient mechanism of bedrock erosion and sedi- ment production (Anderson, 1998; Hales and Roering, 2005, 2007; Delunel et al., 2010, and references therein). As frost-cracking and relat- ed periglacial activities are mostly dependent on temperature-driven ice dynamics and water availability, they are strongly influenced by climatic oscillations. In this context, Anderson (1998) proposed a model in which the relationships between temperature gradients in bedrock and the depth at which frost cracking occurs were addressed. This author proposed that frost-cracking intensities increase at greater depths with decreasing surface temperatures. Hales and Roering (2007) expanded this model by considering hydrologic and heat-flow gradients in order to assess the role of frost-cracking and ice- segregation mechanisms for the conditioning of rockfalls. They suggested that not only the intensity of the frost-cracking increases with depth, but also that the efficiency of the frost-cracking mechanism reaches a maximum where positive mean annual air temperatures (MAATs) of ca. 0 °C prevail. More recently, Anderson et al. (2013) explored the role of regolith production as a function of temperature variations and introduced the concept of limited-water circulation that significantly affects the magnitude of frost-cracking prediction in permafrost environments. They also reported that aspect-related microclimates can influence the transport efficiency on hillslopes via creeping, which partially influences the patterns and rates of denudation. Although these studies indicate an important control of Geomorphology xxx (2015) xxx–xxx ⁎ Corresponding author. Tel.: +49 3319775856. E-mail address: sara.savi@geo.uni-potsdam.de (S. Savi). GEOMOR-05053; No of Pages 13 http://dx.doi.org/10.1016/j.geomorph.2015.01.009 0169-555X/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Geomorphology journal homepage: www.elsevier.com/locate/geomorph Please cite this article as: Savi, S., et al., Efficiency of frost-cracking processes through space and time: An example from the eastern Italian Alps, Geomorphology (2015), http://dx.doi.org/10.1016/j.geomorph.2015.01.009