http://hdl.handle.net/2122/215 Tue, 21 May 2013 19:59:43 GMT 2013-05-21T19:59:43Z http://hdl.handle.net/2122/8711 Title: Geochemical insight into differences in the physical structures and dynamics of two adjacent maar lakes at Mt. Vulture volcano (southern Italy) Authors: Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nuccio, P. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nicolosi, M.; Università di Palermo; Paternoster, M.; Università della Basilicata; Rosciglione, A.; Università di Palermo Abstract: We report on the first geochemical investigation of the Monticchio maar lakes (Mt. Vulture volcano, southern Italy) covering an annual cycle that aimed at understanding the characteristic features of the physical structures and dynamics of the two lakes. We provide the first detailed description of the lakes based on high-resolution CTD profiles, chemical and isotopic (H and O) compositions of the water, and the amounts of dissolved gases (e.g., He, Ar, CH4 and CO2). The combined data set reveals that the two lakes, which are separated by less than 200 m, exhibit different dynamics: one is a meromictic lake, where the waters are rich in biogenic and mantle-derived gases, while the other is a monomictic lake, which exhibits complete turnover of the water in winter and the release of dissolved gases. Our data strongly suggest that the differences in the dynamics of the two lakes are due to different density profiles affected by dissolved solutes, mainly Fe, which is strongly enriched in the deep water of the meromictic lake. A conceptual model of water balance was constructed based on the correlation between the chemical composition of the water and the hydrogen isotopic signature. Gas-rich groundwaters that feed both of the lakes and evaporation processes subsequently modify the water chemistry of the lakes. Our data highlight that no further potential hazardous accumulation of lethal gases is expected at the Monticchio lakes. Nevertheless, geochemical monitoring is needed to prevent the possibility of vigorous gas releases that have previously occurred in historical time. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8711 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8710 Title: Active degassing of mantle-derived fluid: A geochemical study along the Vulture line, southern Apennines (Italy Authors: Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Martelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nuccio, P. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Paternoster, M.; Università della Basilicata; Fin, S.; Isotope Geosciences Unit, Scottish Universities Environmental Research Centre, Abstract: We report the results of a geochemical study of gas emissions along a NE–SW transect in southern Italy in order to test the hypothesis that the region around Monte Vulture is affected by degassing of mantle-derived fluids through a lithospheric discontinuity. We also investigated lavas from the Monte Vulture volcano displaying 3He/4He (up to ~6.0 Ra) and Sr isotopes that are consistent with an origin inmantle that has hadminimal pollution from subducted Adriatic slab. Similar 3He/4He in fluids from around Mt. Vulture indicate that the deep volcanic systemis still degassing. Mantle-derived He occurs in fluids along the length of the Vulture line, reinforcing the hypothesis that it is a deep tectonic discontinuity along which mantle fluids and/or melts advect to the surface. The CO2/3He ratios are highly variable (2.7×108–2.15×1011) in response to processes such as gas dissolution into aquifers, addition of crustal gases and degassing fractionation. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8710 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8697 Title: Sulphur-gas concentrations in volcanic and geothermal areas in Italy and Greece: Characterising potential human exposures and risks Authors: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Aiuppa, A.; Università di Palermo, Dipartimento DiSTeM; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Calabrese, S.; Università di Palermo, Dipartimento DiSTeM; Kyriakopoulos, K.; University of Athens, Dept. Geology and Geoenvironment, Greece; Liotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Longo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Abstract: Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000 μg m−3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000 μg m−3). The data obtained using passive samplers represent time-averaged values over periods from a few days up to 1 month, and hence concentrations probably reached much higher peak values that were potentially also dangerous to healthy people. The present study provides evidence of a peculiar volcanic risk associated with tourist exploitation of active volcanic areas. This risk is particularly high at Mt. Etna, where the elderly and people in less-than-perfect health can easily reach areas with dangerous SO2 concentrations via a cableway and off-road vehicles Wed, 31 Jul 2013 22:00:00 GMT http://hdl.handle.net/2122/8697 2013-07-31T22:00:00Z http://hdl.handle.net/2122/8691 Title: Intersection of exogenous, endogenous and anthropogenic factors in the Holocene landscape: A study of the Naples coastline during the last 6000 years Authors: Romano, P.; Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino 10, 80138 Naples, Italy; Di Vito, M. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Giampaola, D.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Cinque, A.; Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino 10, 80138 Naples, Italy; Bartoli, C.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Boenzi, G.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Detta, F.; Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino 10, 80138 Naples, Italy; Di Marco, M.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Giglio, M.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Iodice, S.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy; Liuzza, V.; Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino 10, 80138 Naples, Italy; Ruello, M. R.; Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino 10, 80138 Naples, Italy; Schiano di Cola, C.; Soprintendenza Speciale ai Beni Archeologici di Napoli e Pompei, Museo Archeologico Nazionale, Naples, Italy Abstract: New data on the ancient landscape of Naples (southern Italy) during the middle and late Holocene from geo-archaeological excavations associated with public transport works were used to reconstruct the hill and coastal environment to the west of the ancient Graeco-Roman polis, where remains of human settlements date to the late Neolithic. The rich stratigraphic and archaeological records that emerged from the digs and from previous boreholes were measured and analysed by combining sedimentary facies analysis, tephrostratigraphy and archaeological data. Between the 5th and 4th millennia BP, a rocky profile with a wave-cut platform cutting across pyroclastites emplaced from the surrounding volcanoes was predominant in the coastal landscape. During the 3rd millennium BP, this rocky coast was progressively replaced by a sandy littoral environment primarily due to marine deposition, with a coastline located some hundred meters inland with respect to the modern one. The sedimentary record of the Greek and Roman periods indicates short-term fluctuations of the coastline, leading to the establishment of a backshore environment towards the end of the 6th century AD, when prograding river mouths and lobes of debris flows contributed to the advancing trend of the shoreline. The frequent archaeological remains from these periods indicate a stable settled area since Roman times. The shoreline was still subject to short-lived fluctuations between the 12th and 16th centuries, and attained its present position during the modern era with man-made reshaping of its profile. The construction of Relative Sea Level curves for two coastal sites reveals that the persistence of the foreshore environment in the Naples coastal strip during the 5th and 4th millennia BP was controlled by the counterbalancing effect of either the concurrent eustatic sea level rise or subsidence. On the other hand, the morpho-stratigraphic record for the last two millennia shows a significant correlation between sedimentation rate and settlement history, accounting for the dominant role of the anthropogenic forcing-factor in late Holocene landscape history. In particular, land mismanagement during Late Antiquity seems to have triggered a slope disequilibrium phase, exacerbating soil erosion and increasing the sediment accumulation rate in both foothill and coastal areas. Nonetheless, the environmental changes of the Chiaia coast during the last 2000 years clearly show volcanicetectonic perturbations influencing coastline development up to the modern era. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8691 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8667 Title: Terrain characterization and structural control of the Auca Mahuida volcanism (Neuquén Basin, Argentina) Authors: Ventura, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; De Ritis, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Longo, M.; Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata, Argentina; Chiappini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: Geomorphometric parameters (slope, aspect, valley depth, and areal density of cones) derived from a moderate resolution digital elevation model with a grid spacing of 100 m are used in an attempt to interpret the tectonic/structural features related to surface deformation in the Auca Mahuida volcanic terrain (Neuquén Basin, Argentina). The Auca Mahuida (2.03–0.88 Ma) is the southernmost volcanic field of the Payenia volcanic province, in the Andean foreland. The foreland is subjected to an E–W compression related to the eastward migration of the N–S striking thrust front of the Andes. The geomorphometric analysis indicates that the Auca Mahuida consists of a basal, E–W elongated lava field with monogenic vents and a summit, polygenic, also E–W elongated, cone. A N100◦E striking fault controls the southern flank of the field, which is also affected by scarps related to erosional and gravity-controlled processes. The drainage network shows a pseudo-radial pattern around the summit cone, and the Auca Mahuida’s deepest valley is structurally controlled by a NNW–SSE striking fault affecting the sedimentary basement. The volcanic field lies on a NE to E dipping substratum. The areal distribution of the monogenic cones is consistent with ascent of magmas along E–W striking fractures, and with elastic models of a pressurized hole (magma chamber) subjected to an E–W compression. At Auca Mahuida, the ascent of melts from the mantle is controlled, in the overriding crust, by tectonic structures formed in response to the E–W compression of the Andes. Wed, 31 Oct 2012 23:00:00 GMT http://hdl.handle.net/2122/8667 2012-10-31T23:00:00Z http://hdl.handle.net/2122/8663 Title: Integrating geologic fault data into tsunami hazard studies Authors: Basili, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Tiberti, M. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Kastelic, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Romano, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Piatanesi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Selva, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Lorito, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: We present the realization of a fault-source data set designed to become the starting point in regional-scale tsunami hazard studies. Our approach focuses on the parametric fault characterization in terms of geometry, kinematics, and assessment of activity rates, and includes a systematic classification in six justification levels of epistemic uncertainty related with the existence and behaviour of fault sources. We set up a case study in the central Mediterranean Sea, an area at the intersection of the European, African, and Aegean plates, characterized by a complex and debated tectonic structure and where several tsunamis occurred in the past. Using tsunami scenarios of maximum wave height due to crustal earthquakes (Mw=7) and subduction earthquakes (Mw=7 and Mw=8), we illustrate first-order consequences of critical choices in addressing the seismogenic and tsunamigenic potentials of fault sources. Although tsunamis generated by Mw=8 earthquakes predictably affect the entire basin, the impact of tsunamis generated by Mw=7 earthquakes on either crustal or subduction fault sources can still be strong at many locales. Such scenarios show how the relative location/orientation of faults with respect to target coastlines coupled with bathymetric features suggest avoiding the preselection of fault sources without addressing their possible impact onto hazard analysis results. Thu, 18 Apr 2013 22:00:00 GMT http://hdl.handle.net/2122/8663 2013-04-18T22:00:00Z http://hdl.handle.net/2122/8661 Title: Biogenic/Abiogenic Hydrocarbons Origin - Possible Role of Tectonically Active Belts Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: The creation of hydrocarbons is linked to tectono-geologic processes and particularly to orogenesis, rifting, overthrusts, erosion, deposition of sediments, deep gas emissions, etc.. Many have claimed the inadequacy of plate tectonics in linearly explain a number of phenomena involved in hydrocarbons generation and geological processes, and many others have defended the synthesis of hydrocarbons starting from inorganic minerals, proposing di erent geochemical processes. In this paper a possible mechanism for production of abiogenic hydrocarbons is proposed, linking it to a previously proposed orogenic isostatic model. While in plate tectonics the cold slab travels in contact with the lithosphere of the continental side, oxidizing materials faced to oxidizing materials, in this model the hightemperature reducing environment of the undepleted mantle rises up and come in contact with the relatively cold oxidizing lithospheric environment. Non-lithostatic overpressures and a number of chemical reactions are then favoured in this sort of tectonic oxidizingreducing pile, leading to a multiple origin of the hydrocarbons. The actual situation along the Italian Apennines orogenic belt seems in accord to the proposed model in which an important role should have the abiogenic hydrocarbons in particular those produced by the tectonic working at the western margin of the Adriatic plate. However, albeit a continuous accumulation of abiogenic hydrocarbons is witnessed by a number of planetary bodies of the Solar system, still no evaluation of the abiogenic/biogenic hydrocarbons rate is possible on our planet. Fri, 30 Nov 2012 23:00:00 GMT http://hdl.handle.net/2122/8661 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8660 Title: Geomorphological evidence from the MAPPA-Web-GIS: explanatory notes Authors: Bini, M.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italia; Bisson, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Capitani, M.; Laboratorio Mappa, Università di Pisa, Pisa, Italia; Noti, V.; Laboratorio Mappa, Università di Pisa, Pisa, Italia; Pappalardo, M.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italia Abstract: Detecting landforms in floodplains is perhaps the most challenging activity for a geomorphologist (Castiglioni 2001). In fact the natural evolution of a floodplain tends to cancel landforms soon after they are no longer active. The Pisa Plain, in particular, was formed in sea-level rise conditions, and thus its evolution was accompanied by a constant rise of base-level. Aggradation was then combined with progradation, resulting in a progressive burial of landforms. Nevertheless those landforms that were buried by more recent alluvium, such as stream channels or marshes, leave a fingerprint which may be visible on modern topography in the form of weak undulations in the ground floor. These are normally undetectable in the field and need an extremely detailed micro-relief representation to be highlighted. Such “inherited” landforms, even if recognized, are then difficult to classify and constrain chronologically. Finally their mutual relationships are hard to assess. Long-aged settlement contributes to modify past fluvial landforms in floodplains, creating an artificial drainage network and enhancing natural topographic highs building artificial ground levels. Specific great-scale surveys are necessary to investigate floodplains geomorphological setting, and a cross-disciplinary approach is in most cases indispensable (Piovan et alii 2006). A Digital Terrain Model reproducing the topography of investigated area with a very high spatial resolution becomes fundamental for studying some landscapes of difficult interpretation as the floodplains where the original morphologies can be lost or modified by the natural environmental changes or by the human activity (Ninfo et alii 2011). Mapping landforms is the first step to perform landscape interpretation. The representation code used by Italian scholars (Servizio Geologico Nazionale, 1994) is a powerful tool that provides all the necessary information to genetically constrain landforms and to assess their mutual relationship in time and space. In this work, though, we preferred not to use this type of representation. In fact in the MAPPA Project all data (archaeological, geological and geomorphological) are included in a digital mapping instrument (the MAPPA web-GIS) which provides access to all the project results for a wide community of end-users, such as researchers, professionals, operators of local public institutions, dealing with archaeological heritage protection, environmental management, natural hazard mitigation. This tool must be simple to consult and must enable real-time queries of data. For this reason a specific legend has been worked out for the MAPPA Web GIS geomorphological map. The milestone of geomorphological maps of the Pisa Plain (Mazzanti 1994) was actually based on cross-checking information on surface lithology with evidence from aerial photography and hystoricalarchaeological data. More recent documents (e.g. Provincia di Pisa http://sit.provincia.pisa.it), improved the resolution of the data but with limited accuracy due to the lack of a suitable topographic base. In the framework of the MAPPA Project new geomorphological evidence was collected thanks to the availability of a Lidar survey and new detailed remote sensing analyses (Bini et alii 2012). The Airborne Lidar Scanning (ALS), acquiring spatially dense altimetry data set over short periods of time, allows the production of very detailed Digital Terrain Models (DTM) even in areas strongly urbanized or covered by dense vegetation. Remote sensing enables to map those features that are hardly detectable in the field due to their scarce relief energy. The nature of surface fingerprints of buried landforms could be verified thanks to the project data base. These new data were represented according to a special code worked out in order to incorporate our data in the MAPPA-Web-GIS; this code will be illustrated in the following, together with the criteria used for landforms detection. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8660 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8658 Title: The Earth Expansion Evidence – A Challenge for Geology, Geophysics and Astronomy Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, E.; University of Bologna; Cwojdzinski, S.; Polish Geological Survey Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Fri, 30 Nov 2012 23:00:00 GMT http://hdl.handle.net/2122/8658 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8634 Title: Methane flux from miniseepage in mud volcanoes of SW Taiwan: Comparison with the data from Italy, Romania, and Azerbaijan Authors: Hong, W.- L..; Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10699, Taiwan; Etiope, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Yang, T. F.; Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10699, Taiwan; Chang, P.- Y.; Institute of Applied Geosciences, National Taiwan Ocean University, No. 2, Pei-Ning Road, Keelung City 202, Taiwan Abstract: Mud volcanoes (MVs) are considered important methane (CH4) sources for the atmosphere; gas is not only released from macro-seepage, i.e., from craters and visible gas bubbling manifestations, but also from invisible and pervasive exhalation from the ground, named miniseepage. CH4 flux related to miniseepage was measured only in a few MVs, in Azerbaijan, Italy, Japan, Romania and Taiwan. This study examines in detail the flux data acquired in 5 MVs and 1 ‘‘dry’’ seep in SW Taiwan, and further compares with other 23 MVs in Italy, Romania and Azerbaijan. Miniseepage from the six manifestations in SW Taiwan MVs and seeps annually contribute at least 110 tons of methane directly to the atmosphere, and represents about 80% of total degassing during a quiescent period. Combining miniseepage flux and geo-electrical data from the Wu-shan-ding MV revealed a possible link between gas flux and electrical resistivity of the vadose zone. This suggests that unsaturated subsoil is a preferential zone for shallow gas accumulation and seepage to the atmosphere. Besides, miniseepage flux in Chu-huo everlasting fire decreases by increasing the distance from the main gas channeling zone and molecular fractionation (methane/ethane ratio) is higher for lower flux seepage, consistently with what observed in other MVs worldwide. Measurements from Azerbaijan, Italy, Romania, and Taiwan converge to indicate that miniseepage is directly proportional to the vent output and it is a significant component of the total methane budget of a MV. A miniseepage vs. macro-seepage flux equation has been statistically assessed and it can be used to estimate theoretically at least the order of magnitude of the flux of miniseepage for MVs of which only the flux from vents was evaluated, or will be evaluated in future. This will allow a more complete and objective quantification of gas emission in MVs, thus also refining the estimate of the global methane emission from geological sources. Sun, 24 Mar 2013 23:00:00 GMT http://hdl.handle.net/2122/8634 2013-03-24T23:00:00Z