Erosion-driven uplift of the modern Central Alps

Abstract

We present a compilation of data of modern tectono-geomorphic processes in the Central European Alps which suggest that observed rock uplift is a response to climate-driven denudation. This interpretation is predominantly based on the recent quantification of basinaveraged Late Holocene denudation rates that are so similar to the pattern and rates of rock uplift rates as determined by geodetic leveling. Furthermore, a GPS data-based synthesis of Adriatic microplate kinematics suggests that the Central Alps are currently not in a state of active convergence. Finally, we illustrate that the Central Alps have acted as a closed system for Holocene redistribution of sediment in which the peri-Alpine lakes have operated as a sink for the erosional products of the inner Central Alps.While various hypotheses have been put forward to explain Central Alpine rock uplift (e.g. lithospheric forcing by convergence, mantle processes, or ice melting) we show with an elastic model of lithospheric deformation, that the correlation between erosion and rock uplift rates reflects a positive feedback between denudation and the associated isostatic response to unloading. Thus, erosion does not passively respond to advection of crustal material as might be the case in actively converging orogens. Rather, we suggest that the geomorphic response of the Alpine topography to glacial and fluvial erosion and the resulting disequilibrium for modern channelized and associated hillslope processes explains much of the pattern of modern denudation and hence rock uplift. Therefore, in a non-convergent orogen such as the Central European Alps, the observed vertical rock uplift is primarily a consequence of passive unloading due to erosion.

Lithological control on the landscape form of the upper Rhône Basin, Central Swiss Alps

“…Wittmann et al (2007) measured Holocene erosion rates in Alpine river sediments, which correlate very well with geodetically based rock uplift rates. These relationships have been used to suggest that vertical movement of rock has mainly been caused by isostatic compensation of removed material (Champagnac et al, 2009). In thematically related studies, several authors concluded that erosion rates directly correlate with geomorphological variables like slope gradients and local-as well as basin-scale relief that can be extracted from digital elevation models (Granger et al, 1996;Schaller et al, 2001;Montgomery and Brandon, 2002).…”

“…These high uplift rates were related to a combination of ongoing collisional processes (Persaud and Pfiffner, 2004), erosional (Champagnac et al, 2009) and glacial unloading (Gudmundsson, 1994). Uplift rates are highest in the eastern part of the study area (1.5 mm a −1 ) and decrease to < 0.3 mm a −1 towards Lake Geneva (Fig.…”

Deciphering neotectonics from river profile analysis in the karst Jura Mountains (northern Alpine foreland)

“…The European Alps are in a post-collisional regime (Champagnac et al 2009;Sue et al 2007;Nocquet 2012;Valla et al 2012), and are characterized by isostatic-related extension and uplift, due to the interaction between buoyancy forces and erosional dynamics (Sue et al 1999;Champagnac et al 2007;Sue et al 2007;Delacou et al 2008;Serpelloni et al 2013;Vernant et al 2013;Baran et al 2014). …”

Seismic and non-seismic influences on coastal change in Alaska--Fieldtrip guide and conference abstracts, 5th International Conference of IGCP 588

“…Most active mountain ranges have been extensively shaped throughout Quaternary glaciation, but have only remnants of glaciers and glacial landforms today. For that reason our understanding of coupling between glacial erosion and tectonic processes is mostly based on the study of the geomorphology of deglaciated landforms (Brocklehurst and Whipple, 2002Whipple, , 2007Champagnac et al, 2009), and on conceptual (Whipple et al, 1999), analytical (Tomkin and Roe, 2007), and numerical models (Tomkin and Braun, 2002;Tomkin, 2007;Herman and Braun, 2008;Yanites and Ehlers, 2012). The St. Elias Range provides the opportunity for direct field investigations of glacial erosion processes in an active orogen and testing glacial erosion models (e.g.…”