Carbon dixide emission in Italy: Shallow crustal sources or subduction related fluid recycling?

Anomalous non-volcanic CO2 release in central and southern Italy has been highlighted by ten years of detailed investigations on Earth degassing processes. Two regional degassing structures are located in the Tyrrhenian sector where more then 200 emissions of CO2 are located and has been recently included in the first web based catalogue of degassing sites (http://googas.ov.ingv.it). The total amount of CO2 released by the two structures were evaluated to be > 2×1011 mol a-1 ( >10% of the estimated global volcanic CO2 emission). The anomalous flux of CO2 suddenly disappears in the Apennine in correspondence of a narrow band where most of the Italian seismicity concentrates. Here, at depth, the gas accumulates in crustal traps generating CO2 overpressurised reservoirs. These overpressured structures are, in our opinion, one of the main cause of Apennine earthquake activation processes. The results of these investigations suggested that Earth degassing in Italy may have an active primary role in the geodynamics of the region. What is the origin of gas? The large extension of the degassing structures and petrologic data suggested that the main source of gas is a mantle metasomatised by the fluids produced in the subdacted slabs. However, has been also hypothesised the presence of localised crustal source of the gas. This matter will be discussed on the base of unpublished isotopic data of the main gas emissions

Carbon Dioxide degassing at Latera caldera (Italy): evidence of geothermal reservoir and evaluation of its potential energy

In order to test the potentiality of soil CO2 diffuse degassing measurements for the study of underground mass and heat transfer in geothermal systems detailed surveys were performed at Latera Caldera which is an excellent test site, due to the abundant available subsurface data. Over 2500 measurements of soil CO2 flux revealed that endogenous CO2 at Latera Caldera concentrates on a NE-SW band coinciding with a structural high of fractured Mesozoic limestones hosting a water-dominated high-enthalpy geothermal reservoir. The total hydrothermal CO2 degassing from the structural high has been evaluated at 350 t d-1 from an area of 3.1 km2. It has been estimated that such a CO2 release would imply a geothermal liquid flux of 263 kg s-1, with a heat release of 239 MW. The chemical and isotopic composition of the gas indicates a provenance from the geothermal reservoir and that CO2 is partly originated by thermal metamorphic decarbonation in the hottest deepest parts of the system and partly has a likely mantle origin. The ratios of CO2, H2, CH2 and CO to Ar, were used to estimate the T-P conditions of the reservoir. Results cluster at T ~ 200-300°C and PCO2 ~ 100-200 bars, close to the actual well measurements. Finally the approach proved to be an excellent tool to investigate the presence of an active geothermal reservoir at depth and that the H2-CO2-CH4-CO-Ar gas composition is a useful T-P geochemical indicator for such CO2 rich geothermal systems

One year of geochemical monitoring of groundwater in the Abruzzi region after the 2009 earthquakes.

The presence of a deep and inorganic source of CO2 has been recently recognized in Italy on the basis of the deeply derived carbon dissolved in the groundwater. In particular, the regional map of CO2 Earth degassing shows that two large degassing structures (Tuscan Roman degassing structure, TRDS, and Campanian degassing structure, CDS) affect the Tyrrhenian side of the Italian peninsula. The comparison between the map of CO2 Earth degassing and of the location of the Italian earthquakes highlights that the anomalous CO2 flux suddenly disappears in the Apennine in correspondence of a narrow band where most of the seismicity concentrates. A previous conceptual model proposed that in this area, at the eastern borders of TRDS and CDS, the CO2 from the mantle wedge intrudes the crust and accumulate in structural traps generating over-pressurized reservoirs. These CO2 over-pressurized levels can play a major role in triggering the Apennine earthquakes. The 2009 Abruzzo earthquakes, like previous seismic crises in the Northern Apennine, occurred at the border of the TRDS, suggesting also in this case a possible role played by deeply derived fluids in the earthquake generation. Detailed hydro-geochemical campaigns, with a monthly frequency, started immediately after the main shock of the 6th of April 2009. The new campaigns include the main springs of the area which were previously studied in detail, during a campaign performed ten years ago, constituting a pre-crisis reference case. Almost one year of geochemical data of the main dissolved ions, of dissolved gases (CO2, CH4, N2, Ar, He) and of the stable isotopes of the water (H, O), CO2 (13C) and He (3He/4He), highlight both that the epicentral area of L’Aquila earthquakes is affected by an important process of CO2 Earth degassing and that that the gases dissolved in the groundwater reflects the input in to the aquifers of a deep gas phase, CO2- rich, with an high He content and with low 3He/4He ratios, similar to the gases emitted by natural manifestations located in the northern Apennines which are fed by deep pressurized reservoirs. Furthermore a systematic increase in the content of the deeply derived CO2 dissolved in the aquifers occurred respect to the July 1997 samples. This increase, followed by a gentle decline of the anomaly, can be compatible with the occurrence of an episode of deep CO2 degassing concurrently with the earthquakes. The origin of this regional variation is under investigation and, at the present moment, an unambiguous interpretation of the data is not possible because the lack of a systematic monitoring of the springs before the seismic events and because eventual seasonal effects on observed variation in CO2 flux are still under investigatio

Handgrip strength predicts persistent walking recovery after hip fracture surgery

Background In older people, hip fractures often lead to disability and death. We evaluated handgrip strength, an objective measure of physical function for bedridden patients, as a predictor of walking recovery in the year after fracture surgery. Methods This multicenter prospective cohort study included 504 patients, aged 70 years or more, who were admitted to the hospital for hip fracture surgery and were formerly able to walk independently. A multidimensional geriatric evaluation that included a physical examination, Short Portable Mental Status Questionnaire, Geriatric Depression Scale, Charlson Index, Basic Activities of Daily Living, and grip strength was administered at the time of admission. Follow-ups were performed every 3 months for 1 year after surgery to assess functional status and survival. The walking recovery probability was evaluated using multivariable logistic regression models. Results The mean age of the participants was 85.3 ± 5.5 years, and 76.1% of the participants were women. The mean grip strength was greater in men (β: 6.6 ± 0.62, P <.001) and was directly related to the Short Portable Mental Status Questionnaire results (P <.001), Basic Activities of Daily Living results (P <.001), serum vitamin D levels (P =.03), and time before surgery (P <.001), whereas it was inversely related to age (P <.001), Geriatric Depression Scale score (P <.001), and Charlson Index (P <.001). After adjusting for confounders, the grip strength was directly associated with the probability of both incident and persistent walking recovery (odds ratio highest tertile vs lowest tertile, 2.84, confidence interval, 1.76-4.59 and 2.79, confidence interval, 1.35-5.79, respectively). Conclusions In older patients with hip fractures, early grip strength evaluation might provide important prognostic information regarding the patient's future functional trajectory. © 2013 Elsevier Inc. All rights reserved

effects of the s process on fe group elements in meteorites

In the present paper we investigate the possible connection between s-process nucleosynthesis occurring during the asymptotic giant branch (AGB) phase of low-mass stars (LMS) and the isotopic anomalies of the "Fe-group" elements observed in several macroscopic samples of meteorites or in grains formed as circumstellar condensates (hereafter CIRCONs). The available measurements of chromium, iron, and nickel are well reproduced by stellar models, which account for the largest shifts in the heaviest isotopes of each element: in particular ^(54)Cr, ^(58)Fe, and ^(64)Ni. Moreover, many circumstellar condensates reflect ^(50)Ti excesses and some production of ^(46, 47, 49)Ti, as predicted by slow-neutron captures in AGB stars. Nevertheless, some difficulties are found in comparing theoretical calculations of s-process nucleosynthesis with calcium, silicon, and zinc isotopic anomalies

Hydrogeochemistry of surface and spring waters in the surroundings of the CO2 injection site at Hontomín–Huermeces (Burgos, Spain)

In this paper the very first geochemical and isotopic data related to surface and spring waters and dissolved gases in the area of Hontomín–Huermeces (Burgos, Spain) are presented and discussed. Hontomín–Huermeces has been selected as a pilot site for the injection of pure (>99%) CO2. Injection and monitoring wells are planned to be drilled close to 6 oil wells completed in the 1980s for which detailed stratigraphical logs are available, indicating the presence of a confined saline aquifer at the depth of about 1500 m into which less than 100,000 tons of iquid CO2 will be injected, possibly starting in 2013. The chemical and features of the spring waters suggest that they are related to a shallow hydrogeological system as the concentration of the Total Dissolved Solids approaches 800 mg/L with a Ca2+(Mg2+)-HCO3− composition, similar to that of the surface waters. This is also supported by the oxygen and hydrogen isotopic ratios that have values lying between those of the Global and the Mediterranean Meteoric Water Lines. Some spring waters close to the oil wells are haracterized by relatively high concentrations of NO3− (up to 123 mg/L), unequivocally suggesting an anthropogenic source that adds to the main water–rock interaction processes. The latter can be referred to Ca-Mg-carbonate and, at a minor extent, Al-silicate dissolution, being the outcropping sedimentary rocks characterized by Palaeozoic to Quaternary rocks. Anomalous concentrations of Cl−, SO42−, As, B and Ba were measured in two springs discharging a few hundred meters from the oil wells and in the Rio Ubierna. These contents are significantly higher than those of the whole set of the studied waters and are possibly indicative of mixing processes, although at very low extent, between deep and shallow aquifers. No evidence of deep-seated gases interacting with the Hontomín–Huermeces waters was recognized in the chemistry of the disolved gases. This is likely due to the fact that they are mainly characterized by an atmospheric source as highlighted by the high contents of N2, O2 and Ar and by N2/Ar ratios that approach that of ASW (Air Saturated Water) and possibly masking any contribution related to a deep source. Nevertheless, significant concentrations (up to 63% by vol.) of isotopically negative CO2 (<−17.7‰ V-PDB) were found in some water samples, likely related to a biogenic source. The geochemical and isotopic data of this work are of particular importance when a monitoring program will be established to verify whether CO2 leakages, induced by the injection of this greenhouse gas, may be affecting the quality of the waters in the shallow hydrological circuits at Hontomín–Huermeces. In this respect, carbonate chemistry, the isotopic carbon of dissolved CO2 and TDIC (Total Dissolved Inorganic Carbon) and selected trace elements can be considered as useful parameters to trace the migration of the injected CO2 into near-surface environments