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  • 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry  (14)
  • 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
  • INGV  (11)
  • Agu  (5)
  • Geological Society of America  (3)
  • MDPI Publishing
  • Nature Publishing Group
  • 2005-2009  (19)
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Years
Year
  • 1
    Publication Date: 2017-04-04
    Description: Thermogenic hydrocarbons entirely deriving from the thermal degradation of organic matter usually exhibit methane to ethane plus propane ratios smaller than 100. We present hydrocarbon distribution data of continental hydrothermal gases, whose methane has been independently identifi ed to derive from the abiogenic reduction of CO2. We fi nd that excess amounts of methane with respect to thermogenic hydrocarbon distributions are characteristic for the investigated gases. A similar pattern is observed for well discharges whose temperatures are too high to support any microbially mediated methanogenesis. These findings strongly suggest that abiogenic methane production in continental-hydrothermal systems is a more widespread process than previously assumed. The maximum contribution of such emissions to the modern atmospheric CH4 budget is estimated at ~1%.
    Description: Published
    Description: 495–498
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: methane ; isotopic composition ; abiogenic hydrocarbons ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
    Publication Date: 2017-04-04
    Description: Le metodologie di indagine geochimica applicate ad un’ampia porzione dell’Appennino meridionale, esteso dalla Calabria settentrionale ai Monti Nebrodi, nell’ambito del progetto INGV-DPC S2, hanno consentito di valutare le caratteristiche dei fluidi emessi in coincidenza di importanti lineamenti strutturali, permettendo di evidenziare le relazioni intercorrenti tra l’assetto tettonico e la genesi, la circolazione ed il comportamento dei fluidi circolanti. L’area di studio rappresenta la porzione più meridionale dell’Arco Calabro, il cui stile deformativo dominante dal Pleistocene medio all’attuale, è caratterizzato da una estensione ESE-WNW. Nella Sicilia nord-orientale, le faglie neotettoniche dislocano i livelli crostali più superficiali e si dispongono secondo direzioni preferenziali orientati circa NW-SE con meccanismi deformativi a componente trascorrente ed estensionale e N-S/NE-SO con meccanismi deformativi trascorrenti, a tratti con componente compressiva. Le strutture crostali radicate sono rappresentate dal sistema “Patti-Eolie”, che si connette a terra con il sistema “Tindari-Letojanni” e dal “sistema di Messina”. Il primo mostra, anche a livello sismologico, caratteri deformativi transtensivi; nel secondo sistema, caratterizzato da faglie a prevalente componente distensiva del rigetto la catena presenta un tasso di sollevamento recente non uniforme, con valori massimi lungo la costa messinese ionica e tassi minori lungo quella tirrenica. L’esistenza di fenomeni attivi di sollevamento regionale è dimostrato da alcune evidenze, come la presenza di argille marine quaternarie affioranti diverse centinaia di metri al di sopra del livello del mare nonché di piattaforme di abrasione tirreniane ben sviluppate ad una altitudine di circa 130 m. nei pressi di Taormina e sul versante calabrese dello stretto di Messina. La struttura tettonica più importante che interseca il sistema Ibleo-Maltese è costituito dal sistema di faglie di Messina, orientato NNE-NNW. Il terremoto di Messina del 1908 è stato attribuito ad una “faglia cieca” nell’area di Messina. Lungo le principali strutture tettoniche, sono presenti attività idrotermali e di degassamento note da tempi storici, che dal punto di vista geochimico mostrano caratteristiche molto diverse in funzione della loro ubicazione.
    Description: Published
    Description: Reggio Calabria
    Description: 3.2. Tettonica attiva
    Description: open
    Keywords: fluidi ; Tettonica attiva ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Extended abstract
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  • 3
    Publication Date: 2017-04-03
    Description: In September 2002, a series of tectonic earthquakes occurred north of Sicily, Italy, followed by three events of volcanic unrest within 150 km. On October 28, 2002, Mt. Etna erupted; on November 3, 2002, submarine degassing occurred near Panarea Island; and on December 28, 2002, Stromboli Island erupted. All of these events were considered unusual: the Mt. Etna NE-rift eruption was the largest in 55 yr, the Panarea degassing was one of the strongest ever detected there, and the Stromboli eruption, which produced a landslide and tsunami, was the largest effusive eruption in 17 yr. Here, we investigate the synchronous occurrence of these clustered unrest events, and develop a possible explanatory model. We compute short-term earthquake-induced dynamic strain changes and compare them to long-term tectonic effects. Results suggest that the earthquake-induced strain changes exceeded annual tectonic strains by at least an order of magnitude. This agitation occurred in seconds, and may have induced fluid and gas pressure migration within the already active hydrothermal and magmatic systems.
    Description: In press
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 3.1. Fisica dei terremoti
    Description: 3.2. Tettonica attiva
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: 3.6. Fisica del vulcanismo
    Description: 4.2. TTC - Scenari e mappe di pericolosità sismica
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: open
    Keywords: earthquake trigger ; magma and gas eruptions ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
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  • 4
    Publication Date: 2017-04-04
    Description: We report here on the real-time measurement of CO2 and SO2 concentrations in the near-vent volcanic gas plume of Mount Etna, acquired by the use of a field portable gas analyzer during a series of periodic field surveys on the volcano’s summit. During the investigated period (September 2004 to September 2005), the plume CO2/SO2 ratio ranged from 1.9 to 10.8, with contrasting composition for Northeast and Voragine crater plumes. Scaling the above CO2/SO2 ratios by UV spectroscopy determined SO2 emission rates, we estimate CO2 emission rates from the volcano in the range 0.9–67.5 kt d 1 (average, 9 kt d 1). About 2 kt of CO2 were emitted daily on average during quiescent passive degassing, whereas CO2 emission rates from Etna’s summit were 10–40 times larger during the 2004–2005 effusive event (with a cumulative CO2 release of 3800 kt during the 6 months of the eruption). Such a syneruptive increase, ascribed to the replenishment of the shallow (〈6 km) volcanic plumbing system by CO2-rich (0.25 wt %) more primitive magmas, supports the potential of CO2 output rates as key parameters for volcanic hazard assessment.
    Description: Published
    Description: B09207
    Description: JCR Journal
    Description: reserved
    Keywords: carbon dioxide ; Mt. Etna ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 5
    Publication Date: 2017-04-04
    Description: A new method using ammonia solutions in pre-evacuated quartz bottles has been experimented for volcanic gas sampling and analysing. Various tests (reproducibility, variability and comparison with known methods such as NaOH pre-evacuated bottles and acid condensates) have been performed to check for their efficiency. By using ammonia solutions, acid gases (St, HCl, HF), carbon dioxide, noncondensible gases (N2, Ar, …) and metallic trace elements (MTE) can be measured with standard methods (HPLC, GC, titrimetry, ICP-MS). Results showthat acid gases, CO2 and noncondensible gases are sampled and analysedwith similar efficiency inNH4OHbottles than by using the known and accurate NaOH method.Moreover, a key point is that NH4OH solutions, after undergoing adequate processing (oxidation and acidification) allow also precise MTE measurements by using standard ICP-MS methods. Such MTE measurements appear much more reliable than those performed on acid condensates. Pre-evacuated ammonia bottles appear therefore as an optimum tool to collect volcanic gases and to obtain their complete chemical composition.
    Description: Published
    Description: 244-256
    Description: JCR Journal
    Description: reserved
    Keywords: lcanic gas; sampling ; acid gases ; noncondensible gases ; metallic trace elements ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 6
    Publication Date: 2017-04-04
    Description: Fissure eruptions may provide important information on the shallow propagation of dikes at volcanoes. Somma-Vesuvius (Italy) consists of the active Vesuvius cone, bordered to the north by the remnants of the older Somma edifice. Historical chronicles are considered to define the development of the 37 fissure eruptions between A.D. 1631 and 1944. The 1631 fissure, which reopened the magmatic conduit, migrated upward and was the only one triggered by the subvertical propagation of a dike. The other 25 fissure eruptions migrated downward, when the conduit was open, through the lateral propagation of radial dikes. We suggest two scenarios for the development of the fissures. When the summit conduit is closed, the fissures are fed by vertically propagating dikes. When the summit conduit is open, the fissures are fed by laterally propagating dikes along the volcano slopes. Consistent behaviors are found at other composite volcanoes, suggesting a general application to our model, independent of the tectonic setting and composition of magma. At Vesuvius, the historical data set and our scenarios are used to predict the consequences of the emplacement of fissures after the opening of the conduit. The results suggest that, even though the probability of opening of vents within the inhabited south and west slopes is negligible, the possibility that these are reached by a lava flow remains significant.
    Description: Published
    Description: 673-676
    Description: reserved
    Keywords: fissures ; dike propagation ; conduit ; Vesuvius ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
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  • 7
    Publication Date: 2017-04-04
    Description: A tomomorphometric analysis of the Somma-Vesuvius topography is presented. This consists in extracting horizontal cross sections at different altitudes, and in determining some morphometric parameters: radius of the circle with a surface area equal to the cross section, circularity, ratio between the major and minor axis of the best fitting ellipse, orientation a of the ellipse major axis, and the x-y centroid. The Somma includes three portions: the apron zone, the flanks, and the summit caldera boundary. Between 225 m and 525 m, a is 50 –60 . Between 600 m and 775 m, a is 130 –135 . These are the preferred strike of the eruptive fissures affecting the northwestern Somma flanks, the faults affecting the whole edifice, the nodal planes from local earthquakes. The Somma activity developed along a NE-SW structural discontinuity, whereas the post-caldera activity concentrated along a NW-SE striking structure. Somma activity migrates from SE to NW.
    Description: Published
    Description: L17305
    Description: JCR Journal
    Description: reserved
    Keywords: Tomomorphometry ; Somma-Vesuvius volcano ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
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  • 8
    Publication Date: 2017-04-04
    Description: Finding the geometry of aquifers in an active volcano is important for evaluating the hazards associated with phreatomagmatic phenomena and incidentally to address the problem of water supply. A combination of electrical resistivity tomography (ERT), self-potential, CO2, and temperature measurements provides insights about the location and pattern of ground water flow at Stromboli volcano. The measurements were conducted along a NE-SW profile across the island from Scari to Ginostra, crossing the summit (Pizzo) area. ERT data (electrode spacing 20 m, depth of penetration of 200 m) shows the shallow architecture through the distribution of the resistivities. The hydrothermal system is characterized by low values of the resistivity (〈50 W m) while the surrounding rocks are resistive (〉2000 W m) except on the North-East flank of the volcano where a cold aquifer is detected at a depth of 80 m (resistivity in the range 70–300 W m). CO2 and temperature measurements corroborate the delineation of the hydrothermal body in the summit part of the volcano while a negative self-potential anomaly underlines the position of the cold aquifer.
    Description: Published
    Description: L17304
    Description: JCR Journal
    Description: reserved
    Keywords: hydrogeology ; Stromboli volcano ; CO2 ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.02. Exploration geophysics::04.02.04. Magnetic and electrical methods ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 9
    Publication Date: 2017-04-04
    Description: This paper presents a comparison between the pattern of surface ruptures produced by a single earthquake and patterns of cumulative deformation. We performed a detailed study of the 1999 earthquake coseismic ruptures and of the long-term tectonic landforms in a key area of the Du¨zce fault segment of the North Anatolian fault. We observed a scaleindependent en echelon arrangement of the coseismic surface ruptures. As a whole, the long-term geomorphic expression of the Du¨zce Fault near the 1999 ruptures is evidence of the principal slip zone at depth that accommodates the bulk of the displacement during an individual rupture event. This may stay localized through many rupture episodes with persistent geometry and kinematics. The long-term tectonic and geomorphic expression of the fault in a broader area around the 1999 ruptures defines a wider deformation zone. In fact, an old and complex fault arrangement has been mapped, partially coinciding with the 1999 rupturing fault, suggesting that the 1999 ruptures are an incomplete expression of the long-term Du¨zce fault system. The relationships between the coseismic and the old fault systems suggest an evolution of the fault pattern trough time, with a tendency to simplify a geometric complexity into a straighter, mature trace. The integrated investigation of long-term tectonic morphologies and structural pattern offers a noteworthy frame to interpret the coseismic rupture kinematics and clarifies their complexities. Moreover, to fully understand the principal slip zone at depth, this work shows the importance of the study of strain distribution pattern and evolution of surface rupturing faults.
    Description: Published
    Description: B06312
    Description: JCR Journal
    Description: reserved
    Keywords: Coseismic ruptures ; tectonic ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
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  • 10
    Publication Date: 2020-11-23
    Description: Gas data of the Los Azufres geothermal field were analyzed using a method based on equilibrium of the Fischer- Tropsch (FT) reaction: CH4 + 2H2O = 4H2 +CO2 and on the combined pyrite-hematite-magnetite (HSH2) reactions: 5/4 H2 +3/2 FeS2 +3/4 Fe2O3 + 7/4 H2O = 3 H2S +Fe3O4 in order to estimate reservoir temperature and excess steam. The solution of equilibrium equations produces a grid (FT-HSH2). This method is suitable for reservoirs with relatively high H2S but low H2 and NH3 concentrations in the fluid as is the case of the Los Azufres well discharges. Reservoir temperature and reservoir excess steam values were estimated for initial and present conditions in representative wells of the field to study the evolution of fluids, because of exploitation and waste fluids reinjection. This method was very useful in estimating reservoir temperatures in vapor wells, while in two-phase wells it was found that as the well produces a smaller fraction of water, the reservoir temperature estimation agrees qualitatively with results from cationic or silica geothermometers. For liquid-dominated wells the reservoir temperature estimations agree with temperatures obtained from the well simulator WELFLO. This indicates that FT-HSH2 results provide the temperature of the fluid entering the well where the last equilibrium occurs. Results show a decrease in reservoir temperatures in the southern zone of the field where intensive reinjection takes place. With exploitation, it was also noted that the deep liquid phase in the reservoir is changing to two-phase increasing the reservoir steam fraction and the non-condensable gases in well discharges.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: Los Azufres geothermal field ; gas geochemistry ; geothermal gas equilibria ; reservoir exploitation ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 11
    Publication Date: 2019-11-04
    Description: Radon-in-soil monitoring at the Poas volcano (Costa Rica) has been performed together with water chemistry from the hot crater lake since 1981 and 1983 respectively. The results are discussed as a function of the eruptive evolution of the volcano over a 13 years period (1981-1994). It is shown that no definitely clear precursory radon signals have been recorded. On the contrary, ionic species concentrations are likely to be considered good precursors, together with the temperature variations of the crater lake water.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: Poas volcano ; geochemistry ; radon ; precursor ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 12
    Publication Date: 2019-11-04
    Description: A theoretical method for estimating the characteristics of radon transport in homogeneous soil is developed. The method allows the following characteristics to be estimated: depth distribution function of the soil gas radon concentration, equilibrium radon concentration in the soil air, depth at which the radon concentration reaches its equilibrium value, radon flux density from the Earths surface, and convective radon transport velocity. The method is based on soil gas radon concentration measurements and is appropriate in the case of relatively uniform geology.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: method ; radon ; soil ; convectiv evelocity ; radon flux density ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 13
    Publication Date: 2019-11-04
    Description: The identified emissions of abiogenic carbon dioxide, carbon monoxide and methane are generally attributed to volcanic activity or to geochemical processes associated with thermometamorphic effects. In this paper we show another possible abiogenic source of emission, induced by mechanical, and not thermal, stresses. We investigated the mechanochemical production of carbon dioxide and methane when friction is applied to marly-type rock and studied the mechanisms determining the strong CO2 and CH4 emissions observed. A ring mill was used to apply friction and oriented pressure upon a synthetic calcite-clay mixture of varying proportions. We found that the CO2 and CH4 release versus the grinding action has a non-linear trend reflecting the behaviour of decreasing crystallinity, which indicates a close link between crystallinity and gas production. For the CO2 emission, we propose a release mechanism connected with the friction-induced fractures and the increase in structural disorders induced by creep in the lattice. The CH4 emission could be explained by a Sabatier reaction in which CO2 and hydrogen are involved to form CH4 and water.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: gas geochemistry ; earthquake precursors ; greenhouse gases ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
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  • 14
    Publication Date: 2019-11-04
    Description: Sampled from the Gangxi oil field in the Huanghua depression, Bohaiwan Basin, the crude oil He and Ar isotopic compositions and their geochemical significance were investigated. The result shows that i) the 3He/4He values of the six oil samples free from air contamination indicate a mantle helium contribution ranging between 13.9% and 32.8% and averaging 24.1%, which means that the Gangxi oil field once had a tectonic background of the mantle-derived helium input and higher geothermal flow with an average of 75.0 mWm-2; ii) deduced from the 40Ar/36Ar aging effect the Gangxi oil should be derived from the Tertiary; iii) water injection is the main reason for the air contamination for the Gangxi oil noble gases and the relations between 3He/4He and 4He/20Ne as well as 40Ar/36Ar and 4He/20Ne are of an applicative potential in estimating the water injection effect and the connectivity of producing formations. The search for the crude oil He and Ar isotopes provides a new approach to inferring natural gas and oil sources, tectonic backgrounds, geothermal flow and water injection effect.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: crude oil ; noble gas tracing ; Gangxi oil field ; Huanghua depression ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 15
    Publication Date: 2019-11-04
    Description: Under strong motion earthquakes, structures receive various types of damage. The most fatal damage is the loss of lateral strengths of a structure. The loss of lateral resistance causes a total collapse of the structure due to the P-d effect associated with the lateral displacements and the gravity loading. To eliminate such a collapse mode, to introduce into the ordinary stiff structure a flexible element which remains elastic is very effective. The flexible-stiff mixed structure can behave preferably in many aspects under strong earthquakes.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: collapse mode ; damage concentration ; P-d effect ; flexible-stiff mixed structure ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
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  • 16
    Publication Date: 2019-11-04
    Description: Long-term geochemical monitoring performed in the seismic area of the Umbria-Marche region of Italy (i.e. Central Apennines) has allowed us to create a model of the circulation of fluids and interpret the temporal chemical and isotopic variations of both the thermal springs as well as the gas vents. Coincident with the last seismic crisis, which struck the region in 1997-1998, an enhanced CO2 degassing on a regional scale caused a pH-drop in all the thermal waters as a consequence of CO2 dissolution. Furthermore, much higher 3He/4He isotope ratios pointed to a slight mantle-derived contribution. Radon activity increased to well above the ±2 sinterval of the earlier seismic period, after which it abruptly decreased to very low levels a few days before the occurrence of the single deep-located shock (March 26, 1998, 51 km deep). The anomalous CO2 discharge was closely related to the extensional movement of the normal faults responsible for the Mw 5.7, 6.0 and 5.6 main shocks that characterized the earlier seismic phase. In contrast, a clear compressive sign is recognizable in the transient disappearance of the deep-originating components related to the Mw 5.3, 51 km-deep event that occurred on March 26, 1998. Anomalies were detected concomitantly with the seismicity, although they also occurred after the seismic crisis had terminated. We argue that the observed geochemical anomalies were driven by rock permeability changes induced by crustal deformations, and we describe how, in the absence of any release of elastic energy, the detection of anomalies reveals that a seismogenic process is developing. Indeed, comprehensive, long-term geochemical monitoring can provide new tools allowing us to better understand the development of seismogenesis.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: geochemical monitoring ; seismicity ; helium ; thermal waters ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 17
    Publication Date: 2019-11-04
    Description: Terrestrial heat flow density, q, is inversely correlated with the age, t, of tectono-magmatic activity in the Earth's crust (Polyak and Smirnov, 1966; etc.). «Heat flow-age dependence» indicates unknown temporal heat sources in the interior considered a priori as the mantle-derived diapirs. The validity of this hypothesis is demonstrated by studying the helium isotope ratio, 3He/4He = R, in subsurface fluids. This study discovered the positive correlation between the regionally averaged (background) estimations of R- and q-values (Polyak et al., 1979a). Such a correlation manifests itself in both pan-regional scales (Norhtern Eurasia) and separate regions, e.g., Japan (Sano et al., 1982), Eger Graben (Polyak et al., 1985) Eastern China rifts (Du, 1992), Southern Italy (Italiano et al., 2000), and elsewhere. The R-q relation indicates a coupled heat and mass transfer from the mantle into the crust. From considerations of heat-mass budget this transfer can be provided by the flux consisting of silicate matter rather than He or other volatiles. This conclusion is confirmed by the correlation between 3He/ 4He and 87Sr/86Sr ratios in the products of the volcanic and hydrothermal activity in Italy (Polyak et al., 1979b; Parello et al., 2000) and other places. Migration of any substance through geotemperature field transports thermal energy accumulated within this substance, i.e. represents heat and mass transfer. Therefore, only the coupled analysis of both material and energy aspects of this transfer makes it possible to characterise the process adequately and to decipher an origin of terrestrial heat flow observed in upper parts of the earth crust. An attempt of such kind is made in this paper.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: heat flow ; helium isotope ratio ; geothermal energy ; mass transfer ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.03. Heat generation and transport
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  • 18
    Publication Date: 2019-11-04
    Description: In order to obtain information on the hydrological signature of rivers during and after heavy rain events, small catchment areas are selected as experimental sites. Hydrograph separations based on environmental tracers are performed. Natural isotopic tracers such as 18O, 2H and particularly 222Rn may help to distinguish the components dominating the outflow, particularly of 'pre-event waters', 'event waters' and 'post-event waters'. Even with moderate concentrations in groundwater, radon can be a very sensitive indicator of groundwater input into rivers. The selected microbasin under investigation is situated in the western part of Luxembourg and belongs to the Attert River catchment. At chosen points at the basin's outflow radon detectors continuously measure radon activity in water. The radon monitors are installed together with high precision thermometers, conductivity meters, flow meters and automatic water samplers for chemical analysis. Besides the continuous measurements, grab water samples are taken at different locations along the stream, most of them during periods of heavy rain events. Presented are the results of a one year measurement campaign. During the dry season i.e. during more or less continuous discharge conditions, the observed mean values do not show substantial variations and can be used as reference values. Fluctuations of the measured data during rain events are discussed and the interplay between the different parameters analysed.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: radon ; hydrology ; tracer ; hydrograph separation ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1312041 bytes
    Format: application/pdf
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  • 19
    Publication Date: 2019-11-04
    Description: Pre-seismic related strains in the Earth s crust are the main cause of the observed geophysical and geochemical anomalies in ground waters preceding an earthquake. Posoc?je Region, situated along the Soc?a River, is one of the most seismically active areas of Slovenia. Our measuring stations close to the Posoc?je Region were installed in the thermal springs at Bled in 1998 and at Zatolmin in 1999. Since the beginning of our survey, radon concentration, electrical conductivity and water temperature have been measured continuously once every hour. In May 2002, the number of geochemical parameters monitored was extended to ionic concentration, pH and Eh, which are analysed once a month. Before seeking a correlation between geochemical and geophysical anomalies with seismic events, the influence of meteorological (atmospheric precipitation, barometric pressure) and hydrological (water table of the Tolminka River) factors on observed anomalies were studied. Results at Zatolmin showed that some radon variation during the period from June to October 2002 may be related to seismic activity and not only to meteorological effects.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: radon ; electrical conductivity ; ions ; thermal springs ; earthquakes ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1456098 bytes
    Format: application/pdf
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