75 research outputs found
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
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
Integrated Multidisciplinary Approach for the Study of the Geothermal Potential of Umbria (Central Italy)
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
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
Influence of depth, temperature, and structure of a crustal heat source on the geothermal reservoirs of Tuscany: numerical modelling and sensitivity study
The development of a new database of gas emissions in Italy: a collaborative web environment for collecting and publishing data on natural gas emissions.
In spite of the large extension of the Earth degassing process and of the correlations with
geodynamic processes and large scale geochemical processes, the Earth degassing process
in the world is still poorly known. Beside the scientific interest on studying gas emissions, a
better knowledge of the degassing process is crucial for mitigate gas hazard correlated to the
release of dangerous gases (e.g., CO2, H2S) from natural emissions, that, like in Italy, caused
many lethal accidents to animals and humans.
After years of data collection organized on a base of a single research group, institution, or
project, there is clearly a need for common frameworks that allow to aggregate data in order to
observe the phenomena at various scale. The development of Googas in 2007 (Chiodini et al.,
2008), funded by the Italian Civil Defence and focused on the serialization of data and the
publication of a web map of gas emissions, was the first attempt to create a collaborative
database on gas emissions. Googas, that represented an important advance in the knowledge of
the phenomenon at the national scale, is however a static representation of the results of the
project.
Starting from the Googas experience, we are now extending the capabilities of Googas on the
user side, developing a new web environment for collecting and publishing data of gas natural
emissions dynamically. The collaborative environment allows researchers from different
institutions to collect data in the most seamless way, and data to be published directly from
within the same system.
The web interface allows to insert data interactively into a spatially referred relational database
management system. Moreover, researchers are aware of the activity of the others and can
access data, leave comments as soon as data is being inserted. This new system aims to
excite, inspire, and encourage participation among researchers.
As gas emissions are inherently referred to geographic locations, published digital data will be
available in several formats, including the ones conformant to Open Gis Consortium (OGC)
standards, for an easy access by using Geographical Information Systems (GIS).
The publication of data on the website will be ruled by a licensing system that facilitates and
encourages the scientific method processes. The license will allow to use and distribute the
data, to produce works from the data and to build up new data from it, as long as these rules are
maintained and the attribution to the original work is being referred. In this way, the efforts to
publish the data are balanced by the guarantees that the data's access will remain open.
This new database of Italian gas emissions is an interesting environment where researchers can
insert data in a common interface asynchronously and the results are immediately tangible. The
development of this project is undergoing and researchers and developers interact closely,
introducing and testing new features during the development phase.
We believe that the development of this new environment represent a starting point towards the
foundation of a collaborative database of gas emissions at global scale.PublishedSan Francisco California USA5.10. TTC - Sistema webope
Advective heat transport associated with regional Earth degassing in central Apennine (Italy)
In this work we show that the main springs of the central Apennine transport a total amount of heat of
∼2.2 109 J s−1. Most of this heat (57%) is the result of geothermal warming while the remaining 43% is
due to gravitational potential energy dissipation. This result indicates that a large area of the central
Apennines is very hot with heat flux values 4300 mWm−2. These values are higher than those
measured in the magmatic and famously geothermal provinces of Tuscany and Latium and about 1/3 of
the total heat discharged at Yellowstone. This finding is surprising because the central Apennines have
been thought to be a relatively cold area. Translated by CO2 rich fluids, this heat anomaly suggests the
existence of a thermal source such as a large magmatic intrusion at depth. Recent tomographic images of
the area support the presence of such an intrusion visible as a broad negative velocity anomaly in seismic
waves. Our results indicate that the thermal regime of tectonically active areas of the Earth, where
meteoric waters infiltrate and deeply circulate, should be revised on the basis of mass and energy
balances of the groundwater systems.Published65–741.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive2.4. TTC - Laboratori di geochimica dei fluidi4.5. Studi sul degassamento naturale e sui gas petroliferiJCR Journalrestricte
Carbon dioxide degassing and thermal energy release in the Monte Amiata volcanic-geothermal area (Italy)
The quaternary volcanic complex of Mount Amiata is located in southern Tuscany (Italy) and represents
the most recent manifestation of the Tuscan Magmatic Province. The region is characterised by a large
thermal anomaly and by the presence of numerous CO2-rich gas emissions and geothermal features,
mainly located at the periphery of the volcanic complex. Two geothermal systems are located, at increasing
depths, in the carbonate and metamorphic formations beneath the volcanic complex. The shallow
volcanic aquifer is separated from the deep geothermal systems by a low permeability unit (Ligurian
Unit). A measured CO2 discharge through soils of 1.8 109 mol a 1 shows that large amounts of CO2
move from the deep reservoir to the surface. A large range in d13CTDIC ( 21.07 to +3.65) characterises
the waters circulating in the aquifers of the region and the mass and isotopic balance of TDIC allows distinguishing
a discharge of 0.3 109 mol a 1 of deeply sourced CO2 in spring waters. The total natural CO2
discharge (2.1 109 mol a 1) is slightly less than minimum CO2 output estimated by an indirect method
(2.8 109 mol a 1), but present-day release of 5.8 109 mol a 1 CO2 from deep geothermal wells may
have reduced natural CO2 discharge. The heat transported by groundwater, computed considering the
increase in temperature from the infiltration area to the discharge from springs, is of the same order
of magnitude, or higher, than the regional conductive heat flow (>200 mWm 2) and reaches extremely
high values (up to 2700mWm 2) in the north-eastern part of the study area. Heat transfer occurs mainly
by conductive heating in the volcanic aquifer and by uprising gas and vapor along fault zones and in those
areas where low permeability cover is lacking. The comparison of CO2 flux, heat flow and geological setting
shows that near surface geology and hydrogeological setting play a central role in determining CO2
degassing and heat transfer patterns
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