Geological evidence of pre-2012 seismic events, Emilia-Romagna, Italy

Riccardo Caputo Riccardo Caputo,Maria Eliana Poli Maria Eliana Poli,Kyriaki Iordanidou Kyriaki Iordanidou,Giorgos Papathanassiou Giorgos Papathanassiou,Marco Stefani Marco Stefani,Sotiris Sboras Sotiris Sboras,Luca Minarelli Luca Minarelli,Adriano Zanferrari Adriano Zanferrari,Dimitra Rapti-Caputo Dimitra Rapti-Caputo

doi:10.4401/ag-6148

Riccardo Caputo Riccardo Caputo, Maria Eliana Poli Maria Eliana Poli + Show 7 more

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https://doi.org/10.4401/ag-6148

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Abstract

<p>In May 2012, two moderate (-to-strong) earthquakes that were associated with a noticeable aftershock sequence affected the eastern sector of the Po Plain, Italy, in correspondence with a buried portion of the Apennines thrust belt. The Provinces of Ferrara, Modena and Bologna (Emilia Romagna Region), Mantua (Lombardy Region), and Rovigo (Veneto Region) were affected to different extents. The first shock (Ml 5.9 according to the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology), and Mw 6.1 according to the US Geological Service) occurred on May 20, 2012, at 2:03 a.m. (GMT); this was the strongest of the sequence, and it was followed by several aftershocks (up to Ml 5.1). This first event produced secondary ground deformation effects, which were mainly associated with liquefaction phenomena that were spread across the broader epicentral region, and particularly in the western sector of the Ferrara Province [Papathanassiou et al. 2012, this volume]. A few weeks after the earthquake, a paleoseismological trench was excavated south of San Carlo village, where earthquake-induced effects were widely documented. This report presents the preliminary results of the paleoseismological investigation and documents the occurrence in the same area of paleo-events older than the May 2012 earthquakes. […]</p>

Highlights

In May 2012, two moderate (-to-strong) earthquakes that were associated with a noticeable aftershock sequence affected the eastern sector of the Po Plain, Italy, in correspondence with a buried portion of the Apennines thrust belt
The trench site As a consequence of the May 20, 2012, earthquake, south of San Carlo village the eastern levee of the paleoReno River was largely affected by a system of parallel ground ruptures, These developed with a systematic NE-SW
Depositional features observed in the trench Due to the abandonment of this Reno River reach, which was dated to the second half of the XVIII century, the investigated sector had preserved the geomorphic expression of the sedimentary bodies well

Summary

Introduction

In May 2012, two moderate (-to-strong) earthquakes that were associated with a noticeable aftershock sequence affected the eastern sector of the Po Plain, Italy, in correspondence with a buried portion of the Apennines thrust belt. 2. Geomorphical and paleogeographic framework In the investigated area, the liquefaction process, the locally associated surface fracturing, and the sand ejection that were induced by the May 20, 2012, earthquake were concentrated along an elongated topographic rise (Figure 1) that stretched from the villages of Sant'Agostino to Vigarano Mainarda, in the south-western portion of the Ferrara Province [Papathanassiou et al 2012].

Results

Conclusion