Geochemistry of fluids discharged over the seismic area of the Southern Apennines (Calabria region, Southern Italy): Implications for Fluid-Fault relationships

The first comprehensive geochemical data-set of the fluids circulating over a 14,000 km2-wide seismicprone area of the Southern Apennines, Calabria Region (Italy), is presented here. The geochemical investigations were carried out with the twofold aim of constraining the origin and interactions of the circulating fluids and to investigate possible relationships with local faults. Sixty samples of both thermal and cold waters were collected, from which the dissolved gases were extracted. The geochemical features of the water samples display different types and degrees of water–rock interactions, irrespective of the outlet temperature. The calculated equilibrium temperatures of the thermal waters (60–160 C) and the low heat flow of thewhole study area, are consistent with a heating process due to deep water circulation and rapid upflow through lithospheric structures. The composition of the dissolved gases reveals that crustal-originating gases (N2 and CO2-dominated) feed all the groundwaters. The 3He/4He ratios of the dissolved He, in the range of 0.03–0.22Rac for the thermal waters and 0.05–0.63Rac for the cold waters (Rac = He isotope ratio corrected for atmospheric contamination), are mainly the result of a two-component (radiogenic and atmospheric) mixing, although indications of mantle-derived He are found in some cold waters. As the study area had been hit by 18 of the most destructive earthquakes (magnitude ranging from 5.9 to 7.2) occurring over a 280-a time span (1626–1908) in the Southern Apennines, the reported results on the circulating fluids may represent the reference for a better inside knowledge of the fault-fluid relationships and for the development of long-term geochemical monitoring strategies for the area

Chemical and isotopic characterisation of gas and water in a scientific

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Radon and helium as pathfinders of fault systems and groundwater evolution in different Italian areas

Groundwater surveys in some Italian areas with different geological and geodynamical features were performed in order to evaluate dissolved rare gases (222Rn, He and Ar) as potential tracers of fault systems and groundwater evolution (fluid origin, water-rock-gas interaction, fluid migration and mixing phenomena). The obtained results showed that the highest values of Rn and He were found along important fault systems cutting the investigated areas, where the fault-related permeability increases deep-seated fluid circulation. However, dissolved-radon anomalies may be due to: a) a rapid ascent of Rn-bearing fluids, equilibrated with lithologies richer in U than outcropping formation; b) a local enrichment of U due to the action of low enthalpy groundwater or strong carrier gas (CO2) discharges usually occurring along the fault systems

Soil-gas survey of liquefaction and collapsed caves during the Emilia seismic sequence

Immediately after the 20th May 2012 Mw 5.9 main shock Emilia earthquake and during the seismic sequence of May-June, 2012, geochemical field investigations were carried out into the epicentral area. This paper provides preliminary soils measurements of CO2 and CH4 performed on widespread liquefactions and ground fractures, occurred after the main shock. Soil gas concentrations and flux measurements on some collapsed caves, already studied in 2008, were repeated again during the seismic sequence of 2012. Observations related to gap forming between buildings and sidewalk, damage of roads, tilting of electricity poles, sand eruption from a well and settlement of ground are also presented

The Tor Caldara CO2 Diffuse Degassing Structure (DDS): 222Rn/220Rn output before and after the August, 22, 2005 Anzio Earthquake (Mw=4.6).

Soon after a 222Rn and 220Rn survey in soil gases, performed (June 2005) in the frame of the Diffuse Degassing in Italy risk assessment project, a moderate earthquake (Mw=4.6) occurred in the Anzio offshore, on August, 22, 2005, only 5 miles from the Tor Caldara Diffuse Degassing Structure (DDS onward). Having available the pre-earthquake 222Rn and 220Rn grid-map on around 50 soil-gas points and being 222Rn both a stress-pathfinder and a discriminative component of activated-faults, a mirrorlike survey was repeated on the same 50 sites, soon after the close earthquake. Later, during a quiescent-aseismic period (December, 2005), a CO2 flux survey was performed for the same 50 sites, adding detailed measurements (more than 100 sites) for the highest flux sectors. The aim of this survey was both to have an overall picture of the background CO2 flux and to calculate the total budget of CO2 flux throughout the DDS, to better interpret the 222Rn and 220Rn areal surveys before and after the seismic event. Herewith, we distinguish the contribution of organic, diffusive and advective CO2 flux. Hints of convection and strong degassing linked to the fracture field, inside the DDS, have been envisaged on selected points, where continuous monitoring stations could be strategic, for seismic, volcanic and NGH surveillance. Despite we found higher 222Rn values in soils after the earthquake, suggesting an enhanced local degassing probably linked to a stress signal throughout the DDS as a whole, the results highlight an unmodified shape and location of the 222Rn anomalies before and after the earthquake. This evidence excludes both that the activated seismogenic segment has affected in some ways both the DDS degassing patterns and that fracture field changed. A similar result could be expected if the activated fault was oriented along the DDS itself and reached the surface. This evidence is well correlated with the reconstructed focal mechanism of the earthquake, pertaining to the transfer structure of the Ardea Graben , located along a peripheral sector of the degassing Alban Hills volcano and intersecting the DDS Tor Caldara itself. The shape and location of 222Rn anomalies inside the DDS for both the surveys are strictly inversely correlated with the areal CO2 flux data. The geometry of the degassing pathways is probably linked to the barrier action (sealing power) of the clays cropping out in the study area. These clays are generated by the strong leaching of the outcropping sedimentary Pleistocene rocks due to the huge flux of volcanic gas -rich fluids

A Multidisciplinary Approach to Earthquake Research: Implementation of a Geochemical Geographic Information System for the Gargano Site, Southern Italy

A priority task for correct environmental planning is to evaluate Natural Hazards, especially in highly populated areas. In particular, thorough investigations based on different Earth Science techniques must be addressed for the Seismic Hazard Assessment (SHA) in tectonically active areas. Not only the management but also the multidisciplinary analysis of all the SHA-related data sets is best performed using a Geographic Information System. In this paper we show how a researchoriented GIS is built and used in a practical case. The Geochemical Geographic Information System (G2IS) was developed and applied to the Gargano promontory (southern Italy) in the framework of an EC research project, the Geochemical Seismic Zonation (GSZ) Project. This multidisciplinary – multiscaling powerful tool is described in its structure, updating procedures and manipulation techniques. Preliminary results are presented on the detection of geochemically active fault zones and their correlation with remote sensing data and other evidences of seismogenic structures.Published255-278JCR Journalreserve

Thermal anomalies and fluid geochemistry framework in occurrence of the 2000-2001 Nizza Monferrate seismic sequence (northern Italy): Episodic changes in the fault zone heat flow or chemical mixing phenomena?

International audienceThe paper discusses the correlation between the heating of shallow groundwater over a 10 × 20 km wide area close to the town of Nizza Monferrato (Piemonte Region, Northern Italy) and the concomitant local seismic sequences during the period August 2000 ? July 2001. The first seismic sequence started on 21 August 2000 with a Ml = 5.2 earthquake. Within few hours, the local authorities received calls alerting that the groundwater temperature rose from 10 to 30°C in many shallow wells. Our geochemical experimental data and the geological-seismotectonic framework do not allow the hypothesis of simple fluid mixing between the thermal reservoir of Acqui Terme and the Nizza-Monferrato shallow groundwater to explain the observed thermal anomalies. On the other hand, we invoke more complex processes such as frictional heating, mechano-chemistry, fault-valve mechanism, adiabatic decompression and hydrogeologically driven heat flow i.e., thermal effects due to variations of basin-scale permeability field. All these processes are able to transmit heat to the surface and to generate a transient incremental heat flow better than the mass transfer occurring typically when fluids from different reservoirs mix

Contribution of Rare and Low-Frequency Variants to Multiple Sclerosis Susceptibility in the Italian Continental Population

Genome-wide association studies identified over 200 risk loci for multiple sclerosis (MS) focusing on common variants, which account for about 50% of disease heritability. The goal of this study was to investigate whether low-frequency and rare functional variants, located in MS-established associated loci, may contribute to disease risk in a relatively homogeneous population, testing their cumulative effect (burden) with gene-wise tests. We sequenced 98 genes in 588 Italian patients with MS and 408 matched healthy controls (HCs). Variants were selected using different filtering criteria based on allelic frequency and in silico functional impacts. Genes showing a significant burden (n = 17) were sequenced in an independent cohort of 504 MS and 504 HC. The highest signal in both cohorts was observed for the disruptive variants (stop-gain, stop-loss, or splicing variants) located in EFCAB13, a gene coding for a protein of an unknown function (p < 10–4). Among these variants, the minor allele of a stop-gain variant showed a significantly higher frequency in MS versus HC in both sequenced cohorts (p = 0.0093 and p = 0.025), confirmed by a meta-analysis on a third independent cohort of 1298 MS and 1430 HC (p = 0.001) assayed with an SNP array. Real-time PCR on 14 heterozygous individuals for this variant did not evidence the presence of the stop-gain allele, suggesting a transcript degradation by non-sense mediated decay, supported by the evidence that the carriers of the stop-gain variant had a lower expression of this gene (p = 0.0184). In conclusion, we identified a novel low-frequency functional variant associated with MS susceptibility, suggesting the possible role of rare/low-frequency variants in MS as reported for other complex diseases

Feasibility study (I stage) of CO2 geological storage by ECBM tecniques in the Sulcis Coal Province (SW Sardinia).

An ECBM feasibility study started for the Sulcis Coal Province (SW Sardinia, Italy): available geochemical, structural-geology, stratigraphic and reservoir engineering considerations as well as the newly gathered experimental data are discussed, including: fluid geochemistry (major and minor elements, dissolved gases, C and He isotopic ratios) of different strata/reservoir, coal composition and experimental data on CO2/CH4 adsorption-desorption on coal. A MapInfo GIS structure was built up including stratigraphic, geo-structural, hydro-geochemical, coal-compositional and environmental-impact information as well as the CO2 sources location and typology. Despite preliminary, these data highlighted both the challenging positive and negative aspects of the Sulcis Coal Province versus the exploitation of the ECBM technique. The most important objective of this phase I of the project is the selection of the best Sulcis ECBM test-pilot site, which will be followed (Phase II-2007) by the choice of a scaled up site and possibly by a future network (Phase III-2008). CO2 geological storage and CH4 production potentials in Sulcis have been grossly evaluated as a whole, in the frame of the Sardinia region CO2 sources, including the coal-fired power plants, both existent and foreseen (hundreds of millions of tonnes of CO2 are possible to be stored underground in the next decades).UnpublishedTrondheim, Norway4.4. Scenari e mitigazione del rischio ambientaleope

Groundwater of Rome

This paper describes the contents of the new Hydrogeological Map of the City of Rome (1:50,000 scale). The map extends to the entire municipality (1285 km2) and is based on both the most recent scientific studies on the groundwater field and new survey activities carried out in order to fill the data gaps in several areas of the examined territory. The map is the result of a combination of different urban groundwater expertise and Geographic Information System (GIS)-based mapping performed using the most recent available data and has been produced with the intention of furnishing the City of Rome with the most recent and updated information regarding groundwater