Patterns of Quaternary uplift of the Corinth rift southern border (N Peloponnese, Greece) revealed by fluvial landscape morphometry

Abstract

The Rift of Corinth is a world-class example of young active rifting and, as such, is an ideal natural laboratory of continental extension. However, though much investigated for two decades, several aspects of the mechanisms at work are still poorly understood. The aim of this paper is a detailed morphometric study of the fluvial landscape response to the tectonic uplift of the rift southern shoulder in order to reconstruct the rift's Quaternary evolution, with special attention to timing, location, and intensity of uplift episodes. Based on the use of a large set of catchment and long profile metrics complemented by the new R/S R integrative approach of the regional drainage network, we identified three distinct episodes of uplift of the northern Peloponnese coastal tract, of which the intermediate one, dated around 0.35-0.4 Ma, is only recorded in the topography of the central part of the rift shoulder, and the youngest one appears to have propagated from east to west over the last 10-20 ka. While net uplift remained minimum in the eastern part of the study area during the whole Quaternary, it shows a clear maximum in the central part of the rift shoulder since 0.4 Ma and an eastward shift of this maximum in recent times. Maximum uplift rates calculated from the morphometric data are of > 1.05 and 2-5 mm year -1 for, the mid-Middle Pleistocene and Holocene uplift episodes, respectively. The morphometric evidence reveals an onshore uplift history remarkably consistent with the rift evolution reconstructed from other data sets. In the long term, it shows a stable pattern of maximum activity in the central part of the rift, confirming previous conclusions about the absence of rift propagation. In the short term, it sheds light on a possible E-W migration of the zone of recent uplift, suggesting that in the near future fault activity and seismic hazard might concentrate in the Heliki-Aegion area, at the western tip of this uplift wave.

Applying Pattern Oriented Sampling in current fieldwork practice to enable more effective model evaluation in fluvial landscape evolution research

“…Viveen et al 2014), (2) the more erosional and morphological records that are often more focused on tectonic forcing (e.g. Beckers et al 2015;Demoulin et al 2015) and (3) study of long-term denudation rates (e.g. Willenbring et al 2013;Veldkamp et al 2016).…”

“…chi plots, hypsometric integrals, geophysical relief, R/SRe.g. Cohen et al 2008;Perron and Royden 2013;Demoulin et al 2015) can be used to quantify field characteristics and integrated into a common geographic information system (GIS) software package, which will facilitate pattern-matching with model output in addition to greater understanding of the Figure 4). Significantly more work is needed to quantify the match between field and modelled data in relation to long profiles however.…”

Testing geomorphic signal of active normal faulting: The case of the Cittanova Fault (Calabria, southern Italy)

“…According to Demoulin et al . (), ‘…the concavity of a real river profile, which is represented by the m/n exponent of A in Equation , will be given by the m/n value in Equation that yields the best linear fit of the z = f ( χ ) profile called the chi plot. Once concavity has been determined, steepness, defined as the coefficient of A in Equation or, similarly, of χ in Equation , simply corresponds to the slope of the regression line’.…”

“…The integral transformation of the river profile's horizontal coordinate into the variable χ (chi) (Perron and Royden, ) offers a viable solution to this problem, since it can be used to reveal the steepness of river reaches independently from the calculation of channel slope. Recently, the χ metric was shown to be useful in detecting the effects of drainage reorganization and particularly the horizontal migration of drainage divides (Mudd et al ., ; Willett et al ., ; Demoulin et al ., ; Yang et al ., ; Harel et al ., ). On the other hand, there has been little work testing its reliability as a proxy of differential displacement along the strike of normal fault segments (Topal et al ., ).…”

Answer to referee 1

“…1a). The delta fronts are highly unstable (Ferentinos et al, 1988;Lykousis et al, 2009), which favors frequent submarine landsliding Tinti et al, 2007;Fig. 1b).…”