Seismotectonics and landslides of the Crati Graben (Calabrian Arc, Southern Italy)

Abstract

The Crati Graben is a depression of Plio-Holocene age mainly controlled by extensional N-S striking faults and WNW-ESE transcurrent faults, in its northern and southern extremity. It is characterized by high landslide susceptibility due to the particular geo-structural pattern and seismotectonic characters. Landslides involve many villages, infrastructure and food crops, bringing serious economic and social damage. The seismotectonic and landslides Main Map of the Crati Graben, described in this paper, represents an update in detail of the framework of landslide risk areas and shows the main active and recent faults of the Crati Graben. The landslides and the faults, have been identified and classified, originally at detail scale (1:5000) and, then, represented at 1:50,000 scale. The geo-structural and geomorphological data were analysed in a geographic information system. The work has revealed a correlation between the trend of faults with respect to the distribution of landslides and of the historical and instrumental seismicity. The work presents an updated knowledge framework of risk conditions of the study zone, where risk areas related to slope instability are hierarchically classified according to the destructive potential of landslides. This document may be therefore a useful reference in planning and prioritising in the design of interventions for the safety of slopes and waterways.ARTICLE HISTORY

Fault‐controlled base‐of‐scarp deposits

“…The Civita section developed in the northern sector of the Crati Basin along a fault‐segment of the 15‐km long Pollino Fault (Colella, 1988a,b; Filice and Seeber, 2019), and pertain to the Pleistocene Synthem (PlS) defined by Spina, Tondi, and Mazzoli (2011; Figure 4a). The Pollino Fault has an oblique normal‐sinistral kinematics (Chiarabba, Agostinetti, & Bianchi, 2016; Ghisetti & Vezzani, 1982; Monaco & Tansi, 1992; Tansi et al., 2007, 2016; Van Dijk et al., 2000) forming a SW facing fault scarp that favoured the formation of several vertically stacked Plio–Pleistocene deltaic units having a total thickness of ~300 m (Colella, 1988b; Figure 4a). Depositional architectures indicate a dominant southwest evolution of the system (Colella, 1988a).…”

Evidences of Soil Consumption Dynamics over Space and Time by Data Analysis in a Southern Italy Urban Sprawling Area

“…The main soil types falling in Rende municipality vary from poorly to moderately differentiated soils [53] such as Fluvisols, Leptosols, Arenosols, Cambisols, Calcisols, The Crati valley represents a tectonic depression NW oriented and situated in axial position respecting the Apennine Chain, and it is limited by faults [49,50]. It is a graben enclosed in three morpho-structural highs: the Sila Massif to the east, the Coastal Chain to the west and south, and the Pollino group to the north [51,52].…”

LiDAR and UAV System Data to Analyse Recent Morphological Changes of a Small Drainage Basin

“…From a geological point of view, the study catchment ( Figure 1B), located on the eastern border of the Crati Graben [36][37][38], consists of Upper Pliocene fine-grained sediments made by marine grey-blue clays and silty clays. The maximum outcropping thickness of the formation is about 100 m. Field surveys highlight that the top of the clay formation is made up of a weathered thickness of yellow-colored silty clays up to 3 m (Figure 3, Photo P1).…”