Roberto De Franco

Italian National Research Council | CNR · Institute of Environmental Geology and Geoengineering IGAG

Multi-refractor imaging is a technique for constructing a single two-dimensional image of a number of refractors by stacking multiple convolved and cross-correlated reversed shot records. The method is most effective with high-fold data that have been obtained with roll-along acquisition programs because the stacking process significantly improves...

A novel experiment of time lapse electrical resistivity tomography (TL-ERT) aimed at monitoring the dynamics of the saltwater intrusion in the coastland bounding the southern Venice Lagoon is presented. A dedicated apparatus was developed and operated for about 9 months from November 2005. The system acquired ten resistivity tomograms per day, five...

This paper presents an overview of the geophysical activities for the seismic microzonation of 138 municipalities belonging to four Italian regions (Abruzzo, Lazio, Marche and Umbria) that were severely damaged by the seismic sequence of Central Italy (August 2016–January 2017). This study is the result of a collaborative effort between research In...

The formation of Cenozoic mountain belts in the Mediterranean realm was preceded by tens of millions of years of subduction, forming volcanic arcs, and frontal contractional systems. In addition, subduction usually involves slab rollback and formation of oceanic backarcs. Although such structure must have influenced the orogeny of Mediterranean mou...

Forward modeling is a fundamental support to study the seismic response of reservoirs structure and subsurface architectures. Carbonate reservoirs result in non-univocal seismic response caused by the facies heterogeneity and due to the possible presence of infilling fluids. The carbonate ramp outcropping in the Majella Massif (Central Italy) is an...

In this paper we present a new methodological approach which integrates geological and geophysical data into a 3D modelling process to be mainly employed in seismic hazard assessment studies of earthquake-prone areas around the world, as well as in applications for land use and urban planning. As a case study, the reconstruction of a geology-based...

The Ceppo Lombardo (C.L.) Formation is a Neogene-Quaternary Clastic Unit of fluvial and/or fluvio-glacer origin, present in Po Plain at N and NE of Milan. The C.L. Formation is a conglomerate with sandstone matrix and/or gravel and/or clastic and the presence of levels of sandstone and locally flow structures. Characteristics and issues of C.L. For...

Large portions of the highly populated central Po Plain in northern Italy are susceptible to major liquefaction–induced ground failure and resulting damage, as illustrated by the 2012 Mw 5.6–5.8 earthquake sequence. Our work presents a comprehensive geomorphological, stratigraphic and geotechnical dataset from a 1012 km² study area in the alluvial...

This paper presents a laboratory experiment where electrical resistivity tomographies (ERTs), joined to surface monitoring with Laser Scanner, were acquired in time-lapse on a sandbox, subjected to impulsive shear strain. The experiment is an attempt to monitoring the different stages characterizing the hydro-geophysical status of a soil prone to l...

In August 2016, a magnitude 6.0 earthquake struck Central Italy, starting a devastating seismic sequence, aggravated by other two events of magnitude 5.9 and 6.5, respectively. After the first mainshock, four Italian institutions installed a dense temporary network of 50 seismic stations in an area of 260 km2. The network was registered in the Inte...

The first mainshock (Mw 6.0) of the 2016 Central Italy seismic sequence, severely struck the Amatrice village and the surrounding localities. After few days, some Italian Institutions, coordinated by the "Center for Seismic Microzonation and its applications", carried out several preparatory activities for seismic microzonation of the area. A tempo...

Synthetic seismic reflection modelling is a useful tool for geothermal exploration as it represents a remarkable support to calibrate geological-geophysical interpretations and model reconstructions, and to explore future seismic reflection acquisition and processing scenarios in geothermal prospecting.

We tested synthetic seismic reflection modelling along a seismic line (CROP-18A) in the geothermal field at Larderello (Italy). This seismic line is characterized by a discontinuous but locally very bright seismic marker, named K-horizon, which has been associated with various geological processes, including the presence of fluids at supercritical...

A geophysical conceptual model for sites prone to seismic liquefaction is presented, introducing a geophysical protocol to characterize the liquefaction proneness. Three parameters are used to characterize homogeneous units: vs, a proxy of the geotechnical classes of soils, vp related to the saturation degree and vp/vs ratio, related to the liquefa...

A geophysical experiment on liquefaction.

Subsidence over the last 0.78 myr of a basin in central Italy bounded by a normal fault caused the deactivation and uplift of an Early-Middle Pleistocene alluvial fan at the fault footwall. Uplift of the fan occurred with a basin-bounding fault slip-rate of the order of 0.2 mm a-1. Subsidence resulted in the reorganization of the river network due...

In the frame of the Integrated Method for Advanced Geothermal Exploration (IMAGE) Project, a reliable exploration and resource assessment workflow was implemented on the basis of an integrated and multidisciplinary approach. Our study addressed to a better understanding of the thermal structure of the deepest part of the Larderello geothermal field...

Although the geology of Italy offers substantial geothermal resources the opportunities for energy production are underexploited and the potential of such resources is almost unknown to the general public. In order to study the societal context of geothermal energy the Italian National Research Council conducted two homogenous case studies that wer...

We have evaluated a technique initially developed for the seismic refraction imaging, the stacked refraction convolution section (SRCS), which we have properly adapted to process ground-penetrating radar (GPR) refraction data. Through a mute operation, the subsurface refracting signals, recorded by the receiver from two reciprocal sources, are sele...

The structural complexity of back-arc basins is related to the evolution of the associated subduction system. Here we present an integrated geophysical and geological study that constrains the 3D spatial variability of magmatic activity along the Tyrrhenian back-arc basin. We use wide-angle seismic and gravity data, acquired in 2010 within the MEDO...

We present a comparison between the results of the processing of seismic profiles acquired in Somaliland, near the town of Boroma, in the frame of an UNESCO project for groundwater research. The main objective of the work was to support the siting of drilling water wells. The aim of geophysical survey was the identification of the geophysical param...

S U M M A R Y Geophysical data from the MEDOC experiment across the Northern Tyrrhenian backarc basin has mapped a failed rift during backarc extension of cratonic Variscan lithosphere. In contrast, data across the Central Tyrrhenian have revealed the presence of magmatic accretion followed by mantle exhumation after continental breakup. Here we an...

The Los Humeros Volcanic Complex (LHVC) is an important geothermal target in the Trans-Mexican Volcanic Belt. Understanding the structure of the LHVC and its influence on the occurrence of thermal anomalies and hydrothermal fluids is important to get insights into the interplay between the volcano-tectonic setting and the characteristics of the geo...

his paper presents the results of an assessment of public views on eventual geothermal energy development in Sicily. The research was carried out under a much wider research project, VIGOR, with the aim to explore the feasibility of geothermal energy utilization in southern Italy. This study has two primary objectives: (1) to explore the views and...

Although Italy has any possible reason to be considered a geothermal country, there appears to be little knowledge or understanding of the potentials of this energy source and its implications for the general society. This paper presents the results of a cultural and social acceptability assessment of geothermal energy exploitation in southern Ital...

Earth pyramids are tall tapered spires, slender or stocky, made of rock or soil material. This type of features have been marginally studied. Even if they are often included in parks and geosites. We start from this lack of studies to analyse the geometrical and physical-mechanical characteristics considering some case studies in northern Italy. Be...

[1] Extension of the continental lithosphere leads to the formation of rift basins, or rifted continental margins if break-up occurs. Seismic investigations have repeatedly shown that conjugate margins have asymmetric tectonic structures, and different amount of extension and crustal thinning. Here, we compare two coincident wide-angle and multicha...

In questo capitolo sono illustrate le campagne sismometriche e le analisi geofisiche-sismologiche finalizzate alla stima sperimentale della risposta di sito e delle caratteristiche amplificative della città di Umbertide e di alcuni siti in località del territorio comunale. Lo studio è stato svolto congiuntamente dall’OGS, Sezione Scientifica Ce...

In questo capitolo sono riassunti gli spettri elastici di risposta in accelerazione lisciati ottenuti dalle analisi numeriche e dalle analisi sperimentali e derivati dalla media degli spetti di risposta ottenuti su ogni singolo punto analizzato applicando i 5 accelerogrammi di input, caratterizzati da un periodo di ritorno di 475 anni (probabi...

1] In this work we investigate the crustal and tectonic structures of the Central Tyrrhenian back-arc basin combining refraction and wide-angle reflection seismic (WAS), gravity, and multichannel seismic (MCS) reflection data, acquired during the MEDOC (MEDiterráneo OCcidental)-2010 survey along a transect crossing the entire basin from Sardinia to...

In the framework of the interdisciplinary MEDOC (MEDiterràneo OCcidental) European project, the crustal structures of the Tyrrhenian basin were explored carrying out the acquisition of five seismic lines. Each line was investigated using both Wide Angle Reflection/Refraction (WARR) and Multichannel Seismic reflection (MCS) techniques. In this prese...

In the framework of the interdisciplinary MEDOC (MEDiterràneo OCcidental) European project, the crustal structures of the Tyrrhenian basin were explored carrying out the acquisition of five seismic lines. Each line was investigated using both Wide Angle Reflection/Refraction (WARR) and Multichannel Seismic reflection (MCS) techniques. In this prese...

In the framework of the interdisciplinary MEDOC (MEDiterràneo OCcidental) European project, the crustal structures of the Tyrrhenian basin were explored carrying out the acquisition of five seismic lines. Each line was investigated using both Wide Angle Reflection/Refraction (WARR) and Multichannel Seismic reflection (MCS) techniques. In this prese...

The 4D-time lapse seismic method allows to determine the changes occurring in a geological reservoir as a result of injection of gas, CO2, water or hydrocarbon production. This method involves acquisition, processing, and interpretation of repeated seismic surveys over the considered geological reservoir. The final result is a time-lapsed differenc...

In the Mondragone area, located at the south eastern edge of the Mt. Massico (Campania region) , hydrothermal evidences has been known since roman time. The area located at the foothill of the Mesozoic carbonatic structure of Mt. Petrino has been chosen to further improve the geothermal knowledge of the area through new geophysical, geological and...

Within more or less karstifed carbonates, fractures generally play an important role both in channelling the geothermal fluid flow and in the hot water storage, making limestones and dolostones among the more important potential geothermal reservoirs, worldwide. Carbonate rocks constitute the backbone of the Italian Apennines that have to be consid...

Extension of the continental lithosphere leads to the formation of rift basins and ultimately may create passive continental margins. The mechanisms that operate during the early stage of crustal extension are still intensely debated. We present the results from coincident multichannel seismic and wide‐angle seismic profiles that transect across th...

The multidisciplinary and integrated review of existing data (mainly acquired during oil exploration), specifically reread for geothermal purposes, and the integration with new data acquired in particular key areas, such as the Mazara Del Vallo site in the southern part of western Sicily, allowed us to better understand this -regional scale- medium...

This paper presents the preliminary results of a cultural and social acceptability assessment of geothermal energy exploitation in southern Italy; this research was carried out in the frame of the national project „VIGOR‟ led by CNR (Italian National Research Council) and the Italian Ministry of Economic Development to investigate the potentials of...

The San Lucano Valley (Belluno, Italy) was the core topic of the symposium: "L'armonia fra uomo e natura nelle valli dolomitiche" held in Agordo (Belluno) on the 12th and 13th November 2010. In this work the valley is analysed according to the following features: geological, geomorpholog-ical, structural, stratigraphic and ecological. The purpose o...

Carbonate aquifers, located in foreland tectonic settings, could represent important thermal water resources outside the volcanic areas, supplying spas or geothermal installations. Thermal springs constitute so the discharge areas of the deep marine and continental groundwaters flowing within these carbonate aquifers whose hydraulic conductivity an...

A characterization of medium enthalpy geothermal resources has been carried out in the Southern Apennines “Guardia Lombardi” site (Campania Region, Italy) within the framework of the Vigor Project. Due to the intense hydrocarbon exploration carried out in Italy since the ‘50, a wide public dataset of well data and seismic reflection profiles is ava...

This interdisciplinary study on the subsurface stratigraphy of the Po Plain (northern Italy) brings new evidence in support of a climate-driven erosional unloading of the Alps since the Middle Pleistocene. A newly acquired, high-resolution seismic profile and a critical review of industrial seismic lines were integrated with sedimentologic observat...

Following the April 6 2009 L’Aquila earthquake, a great effort has been carried out by numerous research institutions for seismic microzonation purposes of urban areas in order to evaluate the seismic potential of the main active faults of the epicentral area. This is the case of the active Mt. Pettino master extensional fault (hereafter PEF) which...

From a geothermal point of view western Sicily is a very interesting area, with the manifestation at surface of several thermal springs, localized areas of moderately high heat flux (more than 90 mW/m 2) and thick carbonates units uninterruptedly developing from surface up top great depths. In this area oil exploration provided new insights for the...