Giorgio Caramanna | Independent Scholar (original) (raw)
Papers by Giorgio Caramanna
We investigated the role of pH reduction, due to natural CO2 release, on the abundance, distribut... more We investigated the role of pH reduction, due to natural CO2 release, on the abundance, distribution and diversity of planktonic prokaryotes in seawater. A field experiment has been carried out during May 2008 on the seafloor east of Panarea Island in the Southern Thyrrenian Sea (Mediterranean Sea). Approaching the vent field pH values decreased from 8.1 to 6.3. Microbial assemblages are under analysis.
Environmental Earth Sciences, 2018
The sinkhole known as 'Pozzo del Merro' possesses unusual, geological and natural features, provi... more The sinkhole known as 'Pozzo del Merro' possesses unusual, geological and natural features, providing an important opportunity to study the geological and hydrological characteristics of the area, and, at the same time, to preserve an ecosystem inhabited by rare species. The site has been the object of numerous studies carried out by scholars from a wide range of disciplines, but a true morphological survey has not been performed until now due to logistical difficulties that include the lack of adequate measuring positions and the difficulty of establishing a clear view between points. The principle benefits of an accurate morphological survey include: (a) a better understanding of the geomorphological characteristics of the site, which will in turn lead to better litho-stratigraphic correlations, (b) the opportunity to obtain accurate measurements of the zero levels of several piezometric measurements, (c) the identification of any secondary cavities which might be hidden by vegetation, and (d) allowing a virtual access to the site to both researchers and general public who cannot currently visit the site due to safety issues and ecosystem vulnerability. These considerations led to the decision to undertake a detailed survey using a combination of different geomatic 'classic' techniques, including the use of total stations, GPS/GNSS geodetic surveying, and laser scanning. The availability of an imaging rover, an innovative photogrammetric multifocal instrument, suggests to repeat the survey to experiment this completely new technology.
Underwater natural emissions of CO2 can be studied to develop detection and monitoring techniques... more Underwater natural emissions of CO2 can be studied to develop detection and monitoring techniques for sub-seabed storage areas. We studied a CO2 degassing area close to the volcanic island of Panarea in the Aeolian Archipelago (Italy). The gas is composed mainly by CO2 (up to 98%) with presence of H2S (up to 2%). The main observed impact on the environment was a general acidification of the seawater. It seems that the thermocline acts as a barrier for the detection of the reduced pH signal. A lab rig was developed to simulate CO2 seepage on water and sediments. Sediments pack the first section of a vertical column of 2 m of length and 40 cm of diameter, the rest is filled with water. CO2 can be injected as gas from the base; sensors will be able to monitor the main chemical parameters and samples can be collected for further analysis. Video-techniques can be applied to study the physical behaviour of the plume of bubbles generated by the injection of the gas through the water.
Årsliste 2007The report gives an overview of the current knowledge about what impacts CO2 leaking... more Årsliste 2007The report gives an overview of the current knowledge about what impacts CO2 leaking from future sub-seabed storage sites may cause to the marine environment. Only a couple of such sites exist today, and no apparent leaks have been detected there. So experience must be gained from other sites where CO2 is emitted naturally from the seabed into the sea, from natural analogues on land, or from experimental work. After learning more about the behaviour and reaction of certain organisms to high-CO2 exposures, monitoring tools and procedures can be established in order to get an early warning of leaks. This may be combined with monitoring techniques for the physical and chemical characteristics of sediments and the seawater above.Norwegian Research Concil - CLIMIT programm
![Research paper thumbnail of [The “Pozzo del Merro” drowned sinkhole: 20 years of exploration and study]](https://attachments.academia-assets.com/99897421/thumbnails/1.jpg)
](Acque sotterranee, Dec 20, 2022
c) Città metropolitana di Roma Capitale-Dipartimento IV-Servizio 2 "Geologico, difesa del suolo, ... more c) Città metropolitana di Roma Capitale-Dipartimento IV-Servizio 2 "Geologico, difesa del suolo, rischio idraulico e territoriale",
The Italian landscape is characterized by a widespread presence of limestone and karst phenomena ... more The Italian landscape is characterized by a widespread presence of limestone and karst phenomena with the formation of caves and sinkholes often hosting springs or small lakes. Scientific diving is a powerful tool to study the geological features of these cavities as it allows for data collection on geomorphology, palaeontology, palaeoclimatology and hydrogeology. Case studies are illustrated of geological investigations in karst springs, sinkholes and submarine caves. Owing to the potentially hazardous environments, sound procedures, training and specific methodologies for data collection have been developed and applied. In all of these situations, direct exploration by scientific diving permitted the collection of information which otherwise would not have been possible to attain.
Carbon Capture and Storage (CCS) aims to capture CO2 from fossil-fuel sources, transport and stor... more Carbon Capture and Storage (CCS) aims to capture CO2 from fossil-fuel sources, transport and store it in suitable geological formations where it will be confined for extremely prolonged times. This is considered a feasible way of mitigating global warming. The seafloor is one of the target areas to safely store large volumes of anthropogenic CO2 through the development of sub-seabed CO2 geological storage. For the UK and large parts of Europe, the North Sea is potentially the most suitable location for CCS projects required to achieve planned targets in the reduction of CO2 emission. Other sub-seabed areas are studied for their storage potential in America and Asia. Even if the technology is considered proven, following the experience gained from the oil industry in using CO2 for enhanced oil recovery (EOR), and a few CO2 storage pilot projects, the risk of CO2 seepage must be addressed considering potential consequences on the marine environment. CO2 emissions may affect the seaflo...
Frontiers in Marine Science, 2021
Submarine fluids emissions in the form of geothermal vents are widespread in a variety of geologi... more Submarine fluids emissions in the form of geothermal vents are widespread in a variety of geological settings ranging from volcanic to tectonically active areas. This overview aims to describe representative examples of submarine vents in shallow-water areas around the globe. The areas described include: Iceland, Azores, Mediterranean Sea (Italy and Greece), Caribbean, Baja California, Japan, Papua, New Zealand, Taiwan. Common and divergent characteristics in terms of origin and geochemistry of the emitted fluids and their impact on the indigenous organisms and the surrounding environment have been identified. In the hottest vents seawater concentration is common as well as some water vapor phase separation. Carbon dioxide is the most common gas often associated with compounds of sulfur and methane. In several vents precipitation of minerals can be identified in the surrounding sediments. The analyses of the microbial communities often revealed putative chemoautotrophs, with Campylo...
Geochemistry, 2015
This study investigates the potential risks associated with high levels and long term exposure of... more This study investigates the potential risks associated with high levels and long term exposure of carbon dioxide (CO2) on the mobility and speciation of exchangeable metals in soils. CO2 incubation batch experiments at high pressure and temperature coupled with geochemical modelling were carried out to elucidate the behavior and mobilisation of metals and the response of soil chemical parameters as a result of long term CO2 exposure. A t-Student analysis was performed to ascertain whether differences in the mean concentration of exchangeable metals in soils before and after CO2incubations are attributable to increase of metal molibilisation because of the long term CO2 exposure. The t-Student revealed the CO2 long term incubation was statistically significant (p<0.05) for the exchangeable concentration of Ni, Zn, and Pb. The CO2-soil incubation induces the acidification of the pore water of soils via CO2 hydrolysis and as a consequence, it increases the exchangeable concentration of Ni, Zn, and Pb in the soils. As, Al, Cr, Cu, and Fe show a different mobilisation pattern depending on the moisture content in soils. Al 3+ , Fe 2+ , Cr 3+ , and Cu 2+ as free cations, As as HAsO2, Pb 2+ and PbHCO3-, Zn 2+ and ZnHCO3-, are predicted to be the predominant aqueous complexes in the pore water of the incubated soils.
Greenhouse Gases: Science and Technology, 2011
Developing reliable detection and monitoring techniques for underwater CO 2 seepage and its effec... more Developing reliable detection and monitoring techniques for underwater CO 2 seepage and its effects on the marine environment is important for a wide range of topics; for example: volcanic surveillance, risk assessment of potential leakages from sub-seabed CO 2 storage sites, and to forecast the effects of ocean acidifi cation. A novel approach is to use areas where natural release of CO 2 is present as 'fi eld-laboratories' for validation of CO 2 monitoring techniques and procedures. One such area was identifi ed close to the volcanic island of Panarea (Italy). Here, CO 2 seeps from the seafl oor in shallow water allowing scuba divers to collect the needed data. Moreover, the coastal setting allows use of small boats for the marine operations, thus strongly reducing the costs. The applied study techniques examined are mainly sampling methods for free and dissolved gases, direct measurement of the CO 2 fl uxes, pH measurement along the water column, and verifi cation of the impact of CO 2 on the local environment. From these fi rst results, the submarine degassing area of Panarea can be realistically considered a natural laboratory where it is possible to test and validate detection methods for the prompt identifi cation of potential seepage from sub-seabed CO 2 storage areas. The particularly favorable environment permits the use of simplifi ed logistics, thus reducing the costs of the research to almost negligible values if compared with any high-seas operation.
Karst phenomena in the Abruzzo region are widespread present due to the diffusion of carbonatic o... more Karst phenomena in the Abruzzo region are widespread present due to the diffusion of carbonatic outcrops, instead the sinkholes phenomena strict sense in the plain areas are still less known and studied. Several landforms, in the past supposed to be related to karst phenomena, could be due to deep piping phenomena triggered by sudden and catastrophic events. Ancient chronicles indicate that these phenomena are related to high magnitude seis-mic events; examples are the collapses during the 1703 Aquila earthquake and 1915 Avezzano earthquakes in the Fucino Plain. Piping sinkholes could have been triggered by these ancient earthquakes, sub-circular ponds, that lie in several plains of the Abruzzo region, could represent these piping sinkholes actually water filled. Areas affected by these phenomena are intermountains tectonic valleys bordered by direct or strike-slip regional faults and filled by thick alluvial deposits (i.e. Sulmona and Fucino plains). In some river valleys, showing ...
Potential CO2 seepage during a CCS project will not only reduce its performing efficiency, but ca... more Potential CO2 seepage during a CCS project will not only reduce its performing efficiency, but can also impact the local environment. Though scientists announce with confidence that CCS is a safe technology to store CO2 deep underground, it is essential to study the effects of CO2 seepage, to avoid any possible influences on soils. As a simplified environment, laboratory experiments can easily be controlled and vital to be studied to be compared with more complex natural analogues and modelling works. Recent research focuses on the effects on ecosystems of CO2 leakage. However, the impacts of long-term, low level exposure for both surface and subsurface ecosystems, as well as soil geochemistry changes are currently not clear. Moreover, previous work has focussed on pure CO2 leakage only and its impacts on the ecosystem. However, in a more realistic scenario the gas coming from a capture process may contain impurities, such as SO2, which are more dangerous than pure CO2 and could cau...
c-34010-Sgonico (TS)-Italy d C.N.R.-I.G.G.-U.O.S. of Rome, c/o Department of Earth Sciences The s... more c-34010-Sgonico (TS)-Italy d C.N.R.-I.G.G.-U.O.S. of Rome, c/o Department of Earth Sciences The studied area is located in the Southern Tyrrhenian Sea near the volcanic island of Panarea (Aeolian Islands, Italy). The degassing area lies two nautical miles east of the main island and is surrounded by several islets and shoals. Here, CO 2 flows steadily from the seafloor in shallow water (10 to 40 metres deep), originating areas of diffuse seepage and several spots of higher gas flow with the formation of bubble plumes. The area, even if not suitable for CO 2 storage, can be considered as a field-lab where it is possible to study the effects of high levels of CO 2 on the marine realm and validate measuring, monitoring and verification (MMV) techniques for sub-seabed CO 2 leakages. The studied area Location of the studied area; the red stars represent the sampled vents The volcanic island of Panarea is characterized by the presence of continuous emission of volcanic gases from the seafloor. In November 2002 the system increased its flow of some order of magnitude and since then a steady release of gas is present generating bubble plumes that, in the shallowest points, reach the sea surface. Due to the environmental conditions, the area close to the shore and shallow water can be utilized as a "natural lab" to study the effect of high levels of CO 2 on the marine realm by surface techniques and directly by means of SCUBA diving. Since 2002, over one hundred hours of diving have been utilized to collect samples of fluids and sediments and to study the biota. After a first phase of volcanic surveillance, the island is more recently studied as a "natural analogue" for the development of reliable monitoring techniques for potential seepage from sub-seabed carbon storage sites. Hereby we present a synthesis of eight years of research in the area.
Greenhouse Gases: Science and Technology, 2012
In sub-seabed storage, CO 2 is injected under the seafl oor in geological structures that are abl... more In sub-seabed storage, CO 2 is injected under the seafl oor in geological structures that are able to trap and retain it. Even if the overall procedure is considered safe, the effects of potential seepage must be addressed in order to develop a reliable risk assessment of the process. This study focuses on the effects of CO 2 seepage on the chemistry of sediments and on the overlying water column in shallow-water environments. To study these effects, an experimental rig was designed, fabricated, and tested. The main unit of the rig is a transparent Plexiglas vertical cylindrical vessel that can be fi lled with sediment in the bottom section and water in the upper part. CO 2 is injected as gas from the bottom through nozzles fed by a CO 2 cylinder. Sensors are used to monitor the variation of the main physical and chemical properties of water and sediments. Gas, water, and sediment samples can be collected for further analysis. The results highlight a fast response of the system to the injected CO 2 with a sharp reduction of the pH values of the interstitial water inside the sediments; once the injection stops, a recovery toward the initial values is recorded. The water above the sediment is also affected by the presence of CO 2 ; in this case the gas-water interaction is controlled by the water movements induced by the rising bubble column.
Energy Procedia, 2014
Laboratory experiments for the assessment of the physical and chemical impact of potential CO 2 s... more Laboratory experiments for the assessment of the physical and chemical impact of potential CO 2 seepage on seawater and freshwater environments.
Energy Procedia, 2013
It is imperative to understand the potential effects of CO 2 seepage on the local environment. Ac... more It is imperative to understand the potential effects of CO 2 seepage on the local environment. Accordingly, a flow through column system was designed and carried out to understand the potential impacts caused by CO 2 seepage, focusing on soil geochemistry changes. The main results of the laboratory experiments indicate that increased levels of CO 2 generate a quick drop in pH for both limestone sand and silica sand, and slightly increased ions concentration in solution phase. Once the seepage is stopped, a partial recovery for limestone sand towards the initial values of pH is recorded.
We investigated the role of pH reduction, due to natural CO2 release, on the abundance, distribut... more We investigated the role of pH reduction, due to natural CO2 release, on the abundance, distribution and diversity of planktonic prokaryotes in seawater. A field experiment has been carried out during May 2008 on the seafloor east of Panarea Island in the Southern Thyrrenian Sea (Mediterranean Sea). Approaching the vent field pH values decreased from 8.1 to 6.3. Microbial assemblages are under analysis.
Environmental Earth Sciences, 2018
The sinkhole known as 'Pozzo del Merro' possesses unusual, geological and natural features, provi... more The sinkhole known as 'Pozzo del Merro' possesses unusual, geological and natural features, providing an important opportunity to study the geological and hydrological characteristics of the area, and, at the same time, to preserve an ecosystem inhabited by rare species. The site has been the object of numerous studies carried out by scholars from a wide range of disciplines, but a true morphological survey has not been performed until now due to logistical difficulties that include the lack of adequate measuring positions and the difficulty of establishing a clear view between points. The principle benefits of an accurate morphological survey include: (a) a better understanding of the geomorphological characteristics of the site, which will in turn lead to better litho-stratigraphic correlations, (b) the opportunity to obtain accurate measurements of the zero levels of several piezometric measurements, (c) the identification of any secondary cavities which might be hidden by vegetation, and (d) allowing a virtual access to the site to both researchers and general public who cannot currently visit the site due to safety issues and ecosystem vulnerability. These considerations led to the decision to undertake a detailed survey using a combination of different geomatic 'classic' techniques, including the use of total stations, GPS/GNSS geodetic surveying, and laser scanning. The availability of an imaging rover, an innovative photogrammetric multifocal instrument, suggests to repeat the survey to experiment this completely new technology.
Underwater natural emissions of CO2 can be studied to develop detection and monitoring techniques... more Underwater natural emissions of CO2 can be studied to develop detection and monitoring techniques for sub-seabed storage areas. We studied a CO2 degassing area close to the volcanic island of Panarea in the Aeolian Archipelago (Italy). The gas is composed mainly by CO2 (up to 98%) with presence of H2S (up to 2%). The main observed impact on the environment was a general acidification of the seawater. It seems that the thermocline acts as a barrier for the detection of the reduced pH signal. A lab rig was developed to simulate CO2 seepage on water and sediments. Sediments pack the first section of a vertical column of 2 m of length and 40 cm of diameter, the rest is filled with water. CO2 can be injected as gas from the base; sensors will be able to monitor the main chemical parameters and samples can be collected for further analysis. Video-techniques can be applied to study the physical behaviour of the plume of bubbles generated by the injection of the gas through the water.
Årsliste 2007The report gives an overview of the current knowledge about what impacts CO2 leaking... more Årsliste 2007The report gives an overview of the current knowledge about what impacts CO2 leaking from future sub-seabed storage sites may cause to the marine environment. Only a couple of such sites exist today, and no apparent leaks have been detected there. So experience must be gained from other sites where CO2 is emitted naturally from the seabed into the sea, from natural analogues on land, or from experimental work. After learning more about the behaviour and reaction of certain organisms to high-CO2 exposures, monitoring tools and procedures can be established in order to get an early warning of leaks. This may be combined with monitoring techniques for the physical and chemical characteristics of sediments and the seawater above.Norwegian Research Concil - CLIMIT programm
Acque sotterranee, Dec 20, 2022
c) Città metropolitana di Roma Capitale-Dipartimento IV-Servizio 2 "Geologico, difesa del suolo, ... more c) Città metropolitana di Roma Capitale-Dipartimento IV-Servizio 2 "Geologico, difesa del suolo, rischio idraulico e territoriale",
The Italian landscape is characterized by a widespread presence of limestone and karst phenomena ... more The Italian landscape is characterized by a widespread presence of limestone and karst phenomena with the formation of caves and sinkholes often hosting springs or small lakes. Scientific diving is a powerful tool to study the geological features of these cavities as it allows for data collection on geomorphology, palaeontology, palaeoclimatology and hydrogeology. Case studies are illustrated of geological investigations in karst springs, sinkholes and submarine caves. Owing to the potentially hazardous environments, sound procedures, training and specific methodologies for data collection have been developed and applied. In all of these situations, direct exploration by scientific diving permitted the collection of information which otherwise would not have been possible to attain.
Carbon Capture and Storage (CCS) aims to capture CO2 from fossil-fuel sources, transport and stor... more Carbon Capture and Storage (CCS) aims to capture CO2 from fossil-fuel sources, transport and store it in suitable geological formations where it will be confined for extremely prolonged times. This is considered a feasible way of mitigating global warming. The seafloor is one of the target areas to safely store large volumes of anthropogenic CO2 through the development of sub-seabed CO2 geological storage. For the UK and large parts of Europe, the North Sea is potentially the most suitable location for CCS projects required to achieve planned targets in the reduction of CO2 emission. Other sub-seabed areas are studied for their storage potential in America and Asia. Even if the technology is considered proven, following the experience gained from the oil industry in using CO2 for enhanced oil recovery (EOR), and a few CO2 storage pilot projects, the risk of CO2 seepage must be addressed considering potential consequences on the marine environment. CO2 emissions may affect the seaflo...
Frontiers in Marine Science, 2021
Submarine fluids emissions in the form of geothermal vents are widespread in a variety of geologi... more Submarine fluids emissions in the form of geothermal vents are widespread in a variety of geological settings ranging from volcanic to tectonically active areas. This overview aims to describe representative examples of submarine vents in shallow-water areas around the globe. The areas described include: Iceland, Azores, Mediterranean Sea (Italy and Greece), Caribbean, Baja California, Japan, Papua, New Zealand, Taiwan. Common and divergent characteristics in terms of origin and geochemistry of the emitted fluids and their impact on the indigenous organisms and the surrounding environment have been identified. In the hottest vents seawater concentration is common as well as some water vapor phase separation. Carbon dioxide is the most common gas often associated with compounds of sulfur and methane. In several vents precipitation of minerals can be identified in the surrounding sediments. The analyses of the microbial communities often revealed putative chemoautotrophs, with Campylo...
Geochemistry, 2015
This study investigates the potential risks associated with high levels and long term exposure of... more This study investigates the potential risks associated with high levels and long term exposure of carbon dioxide (CO2) on the mobility and speciation of exchangeable metals in soils. CO2 incubation batch experiments at high pressure and temperature coupled with geochemical modelling were carried out to elucidate the behavior and mobilisation of metals and the response of soil chemical parameters as a result of long term CO2 exposure. A t-Student analysis was performed to ascertain whether differences in the mean concentration of exchangeable metals in soils before and after CO2incubations are attributable to increase of metal molibilisation because of the long term CO2 exposure. The t-Student revealed the CO2 long term incubation was statistically significant (p<0.05) for the exchangeable concentration of Ni, Zn, and Pb. The CO2-soil incubation induces the acidification of the pore water of soils via CO2 hydrolysis and as a consequence, it increases the exchangeable concentration of Ni, Zn, and Pb in the soils. As, Al, Cr, Cu, and Fe show a different mobilisation pattern depending on the moisture content in soils. Al 3+ , Fe 2+ , Cr 3+ , and Cu 2+ as free cations, As as HAsO2, Pb 2+ and PbHCO3-, Zn 2+ and ZnHCO3-, are predicted to be the predominant aqueous complexes in the pore water of the incubated soils.
Greenhouse Gases: Science and Technology, 2011
Developing reliable detection and monitoring techniques for underwater CO 2 seepage and its effec... more Developing reliable detection and monitoring techniques for underwater CO 2 seepage and its effects on the marine environment is important for a wide range of topics; for example: volcanic surveillance, risk assessment of potential leakages from sub-seabed CO 2 storage sites, and to forecast the effects of ocean acidifi cation. A novel approach is to use areas where natural release of CO 2 is present as 'fi eld-laboratories' for validation of CO 2 monitoring techniques and procedures. One such area was identifi ed close to the volcanic island of Panarea (Italy). Here, CO 2 seeps from the seafl oor in shallow water allowing scuba divers to collect the needed data. Moreover, the coastal setting allows use of small boats for the marine operations, thus strongly reducing the costs. The applied study techniques examined are mainly sampling methods for free and dissolved gases, direct measurement of the CO 2 fl uxes, pH measurement along the water column, and verifi cation of the impact of CO 2 on the local environment. From these fi rst results, the submarine degassing area of Panarea can be realistically considered a natural laboratory where it is possible to test and validate detection methods for the prompt identifi cation of potential seepage from sub-seabed CO 2 storage areas. The particularly favorable environment permits the use of simplifi ed logistics, thus reducing the costs of the research to almost negligible values if compared with any high-seas operation.
Karst phenomena in the Abruzzo region are widespread present due to the diffusion of carbonatic o... more Karst phenomena in the Abruzzo region are widespread present due to the diffusion of carbonatic outcrops, instead the sinkholes phenomena strict sense in the plain areas are still less known and studied. Several landforms, in the past supposed to be related to karst phenomena, could be due to deep piping phenomena triggered by sudden and catastrophic events. Ancient chronicles indicate that these phenomena are related to high magnitude seis-mic events; examples are the collapses during the 1703 Aquila earthquake and 1915 Avezzano earthquakes in the Fucino Plain. Piping sinkholes could have been triggered by these ancient earthquakes, sub-circular ponds, that lie in several plains of the Abruzzo region, could represent these piping sinkholes actually water filled. Areas affected by these phenomena are intermountains tectonic valleys bordered by direct or strike-slip regional faults and filled by thick alluvial deposits (i.e. Sulmona and Fucino plains). In some river valleys, showing ...
Potential CO2 seepage during a CCS project will not only reduce its performing efficiency, but ca... more Potential CO2 seepage during a CCS project will not only reduce its performing efficiency, but can also impact the local environment. Though scientists announce with confidence that CCS is a safe technology to store CO2 deep underground, it is essential to study the effects of CO2 seepage, to avoid any possible influences on soils. As a simplified environment, laboratory experiments can easily be controlled and vital to be studied to be compared with more complex natural analogues and modelling works. Recent research focuses on the effects on ecosystems of CO2 leakage. However, the impacts of long-term, low level exposure for both surface and subsurface ecosystems, as well as soil geochemistry changes are currently not clear. Moreover, previous work has focussed on pure CO2 leakage only and its impacts on the ecosystem. However, in a more realistic scenario the gas coming from a capture process may contain impurities, such as SO2, which are more dangerous than pure CO2 and could cau...
c-34010-Sgonico (TS)-Italy d C.N.R.-I.G.G.-U.O.S. of Rome, c/o Department of Earth Sciences The s... more c-34010-Sgonico (TS)-Italy d C.N.R.-I.G.G.-U.O.S. of Rome, c/o Department of Earth Sciences The studied area is located in the Southern Tyrrhenian Sea near the volcanic island of Panarea (Aeolian Islands, Italy). The degassing area lies two nautical miles east of the main island and is surrounded by several islets and shoals. Here, CO 2 flows steadily from the seafloor in shallow water (10 to 40 metres deep), originating areas of diffuse seepage and several spots of higher gas flow with the formation of bubble plumes. The area, even if not suitable for CO 2 storage, can be considered as a field-lab where it is possible to study the effects of high levels of CO 2 on the marine realm and validate measuring, monitoring and verification (MMV) techniques for sub-seabed CO 2 leakages. The studied area Location of the studied area; the red stars represent the sampled vents The volcanic island of Panarea is characterized by the presence of continuous emission of volcanic gases from the seafloor. In November 2002 the system increased its flow of some order of magnitude and since then a steady release of gas is present generating bubble plumes that, in the shallowest points, reach the sea surface. Due to the environmental conditions, the area close to the shore and shallow water can be utilized as a "natural lab" to study the effect of high levels of CO 2 on the marine realm by surface techniques and directly by means of SCUBA diving. Since 2002, over one hundred hours of diving have been utilized to collect samples of fluids and sediments and to study the biota. After a first phase of volcanic surveillance, the island is more recently studied as a "natural analogue" for the development of reliable monitoring techniques for potential seepage from sub-seabed carbon storage sites. Hereby we present a synthesis of eight years of research in the area.
Greenhouse Gases: Science and Technology, 2012
In sub-seabed storage, CO 2 is injected under the seafl oor in geological structures that are abl... more In sub-seabed storage, CO 2 is injected under the seafl oor in geological structures that are able to trap and retain it. Even if the overall procedure is considered safe, the effects of potential seepage must be addressed in order to develop a reliable risk assessment of the process. This study focuses on the effects of CO 2 seepage on the chemistry of sediments and on the overlying water column in shallow-water environments. To study these effects, an experimental rig was designed, fabricated, and tested. The main unit of the rig is a transparent Plexiglas vertical cylindrical vessel that can be fi lled with sediment in the bottom section and water in the upper part. CO 2 is injected as gas from the bottom through nozzles fed by a CO 2 cylinder. Sensors are used to monitor the variation of the main physical and chemical properties of water and sediments. Gas, water, and sediment samples can be collected for further analysis. The results highlight a fast response of the system to the injected CO 2 with a sharp reduction of the pH values of the interstitial water inside the sediments; once the injection stops, a recovery toward the initial values is recorded. The water above the sediment is also affected by the presence of CO 2 ; in this case the gas-water interaction is controlled by the water movements induced by the rising bubble column.
Energy Procedia, 2014
Laboratory experiments for the assessment of the physical and chemical impact of potential CO 2 s... more Laboratory experiments for the assessment of the physical and chemical impact of potential CO 2 seepage on seawater and freshwater environments.
Energy Procedia, 2013
It is imperative to understand the potential effects of CO 2 seepage on the local environment. Ac... more It is imperative to understand the potential effects of CO 2 seepage on the local environment. Accordingly, a flow through column system was designed and carried out to understand the potential impacts caused by CO 2 seepage, focusing on soil geochemistry changes. The main results of the laboratory experiments indicate that increased levels of CO 2 generate a quick drop in pH for both limestone sand and silica sand, and slightly increased ions concentration in solution phase. Once the seepage is stopped, a partial recovery for limestone sand towards the initial values of pH is recorded.