Natural CO2 Seeps Offshore Panarea: A Test Site for Subsea CO2 Leak Detection Technology (original) (raw)
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Natural CO2Seeps Offshore Panarea: A Test Site for Subsea CO2Leak Detection Technology
Marine Technology Society Journal, 2015
DuringRV Poseidoncruise POS469 (May 2014), the distribution ofpCO2in the near field of submarine volcanic gas flares in shallow water depths down to 50 m below sea level was continuously monitored using three different and independent methodologies.In situnondispersive infrared (NDIR) spectrometry, pH measurements, and onboard membrane inlet mass spectrometry (MIMS) were used to determine the fate of rising CO2bubbles and the dissolved CO2plume patterns in a 300 × 400-m working area. TheIn situsensor carrier platform, a towed video-controlled water sampling rosette, equipped with CTD sensors, guaranteed excellent ground truthing of seafloor characteristics and bubble discharge. Sensor data and near-seafloor observations indicated that the gas bubbles (<9 mm in diameter, >97 vol.% of CO2) dissolved very rapidly within the first 10 m above seafloor. Bottom water masses enriched withpCO2(up to 1,100 μatm) show low pH values (up to 7.80) and tend to spread rather downslope west th...
Monitoring techniques of a natural analogue for sub-seabed CO2 leakages
Energy Procedia, 2011
Carbon dioxide sequestration in sub-seafloor aims to store CO 2 inside geological trapping structures below the seafloor. However there are concerns related to the possibility of leakage from the storage sites and potential consequences on the marine environment. In order to develop safe and reliable methods for CO 2 monitoring, field studies were conducted in a natural analogue-an area where there is a natural release of CO 2 from the seafloor. Due to the very high volume of gas emitted, this natural analogue could be considered as the worst-case scenario for a possible leakage from a sub-seabed storage site. Sampling procedures for free and dissolved gas and measuring techniques of the main physical and chemical parameters were developed for use both from the surface and directly underwater by scientific scuba divers. The first results of the research indicate that high levels of CO 2 released in the marine realm strongly affect the local environmental conditions with a generalized acidification of the seawater. The experience gained in this study allows further development of a more accurate and suitable monitoring suite that will integrate sensors for measuring pH, dissolved CO 2 , and eventually, acoustic systems for the detection, monitoring and quantification of gas bubbles. The monitoring system could be deployed on the seafloor for long-term monitoring or could be carried onboard movable platforms such as ROV's (Remote Operated Vehicles) or AUV's (Autonomous Underwater Vehicles) for systematic surveys of the sub-seabed storage areas.
Applied Geochemistry, 2010
To understand the effects of increased levels of CO2 on the marine realm, it is possible to study areas where, for natural reasons, there are emissions of CO2 from the seabed. One of these areas is located east of Panarea Island (Aeolian Islands – Southern Tyrrhenian Sea – Italy). Here, the volcanic activity that characterizes the Aeolian archipelago causes a continuous release of CO2 (up to 98% of the total gas) from several vents on the seafloor in shallow water. This area was studied by means of surface techniques and direct SCUBA diving surveys; the data presented refers to a field campaign performed in 2008. To collect the necessary data, some dedicated sampling and measuring techniques were developed for use in an underwater environment. The chemistry of the fluids and their influence on the water body was determined via logs and transects in the field and by gas-chromatographic and liquid-chromatographic laboratory analysis. The flux from some of the main gas vents was also measured directly underwater. Furthermore, some laboratory experiments in a two-layer stratified fluid were conducted to understand the main features of the physical interaction of a gas plume with the surrounding environment. Both field and laboratory experiments show that there is a development of a pseudo-convective cell around the rising plume with the formation of vortices that act as a physical barrier thus reducing the interaction between the plume and the surrounding water.
Greenhouse Gases: Science and Technology, 2011
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.
Use of the Panarea Natural Test Laboratory for Offshore CO2 Leakage Monitoring and Impact Studies
Fourth EAGE CO2 Geological Storage Workshop, 2014
The natural CO2 leaking site near Panarea Island, Italy, has been used as a field laboratory to study potential impacts of CO2 on surface water chemistry and biology and to test innovative monitoring tools. Work involved 4 campaigns, one for each season, in which a 700 m long transect was sampled, benthic chamber measurements were made, and ADCP current measurements were conducted. In addition, an in house developed pCO2 continuous monitoring station was deployed for a 6 month period, during which it measured temperature and pCO2 values once every two hours and transmitted the values in real time to a web-based server. Results show the complexity of working at a real world site, as the dynamic marine system results in plume smearing and rapid dilution of the leakage signal. While making monitoring more difficult, this dilution means that impact will be limited (at least at leakage rates comparable to the Panarea site). In addition, the results also imply that future biological impact studies must take into account temporal variability, and not address only static pCO2 conditions.
Development of an innovative marine monitoring system for CO2 leaks: system design and testing
Energy Procedia, 2009
A critical component of long term geological sequestration of anthropogenic CO 2 will be our ability to adequately monitor a chosen site to ensure public and environmental safety. Near surface monitoring is particularly important, as it is possible to conduct sensitive and direct measurements at the boundary between the subsurface and the biosphere (i.e. surface water or atmosphere). While discontinuous surface monitoring is often performed, continuous monitoring is preferable if one hopes to observe a leak in its early stages to allow for rapid remedial action. The geochemical signal that may result from a near-surface CO 2 leak might take the form of increased soil gas concentrations (on land) or changing pH, Eh, and aqueous chemistry (in groundwater or surface water), and thus continuous monitoring stations capable of analyzing for these parameters have great potential for early leak detection. In the framework of the EC-funded CO2GeoNet and CO2ReMoVe projects innovative monitoring systems have been designed and constructed for autonomous deployment in marine environments above geological CO 2 storage sites. The system developed within CO2GeoNet was tested at a site in the Gulf of Trieste where there is no gas release; this site was chosen due to easy access and the presence of an existing oceanographic buoy onto which the monitoring station was mounted. Tests on this early prototype highlighted the various difficulties of working in marine environments, and this experience formed the basis for a new system developed for deployment at the Panarea test site within CO2ReMoVe. This second site is located off the coast of Panarea Island, to the north of Sicily, where naturally-produced CO 2 leaks from the seabed into the water column. The advantage of this site is that the leaks occur in a relatively near-shore environment (<300m) and in water that is not too deep (<25m), thereby allowing for easy access by SCUBA divers for system testing and maintenance. This location allowed the unit to be connected via cable, rather than a buoy, which makes power supply and data transfer simpler. The system developed for this site consists of three monitoring points that are connected to a land-based control unit. Each point, located 100, 200, and 300m from shore in different CO 2 flux regimes, is able to measure dissolved CO 2 and CH 4 , conductivity, pH, and temperature using low cost but sensitive sensors. The complete system consists of flexible solar panels, a central control unit and three monitoring points, and data download is conducted using a GPRS connection and a web server. Difficulties with the initial deployment in early April of 2008 has necessitated further development work, with the second deployment planned for early November. The following paper discussed the experience gained with these stations, and presents data analysis and anomaly recognition from a land-based monitoring station that has been collecting dissolved CO 2 data for over 18 months.
Detection and impacts of leakage from sub-seafloor deep geological carbon dioxide storage
Nature Climate Change, 2014
Fossil fuel power generation and other industrial emissions of carbon dioxide are a threat to global climate 1 , yet many economies will remain reliant on these technologies for several decades 2 . Carbon dioxide capture and storage (CCS) in deep geological formations provides an e ective option to remove these emissions from the climate system 3 . In many regions storage reservoirs are located o shore 4,5 , over a kilometre or more below societally important shelf seas 6 . Therefore, concerns about the possibility of leakage 7,8 and potential environmental impacts, along with economics, have contributed to delaying development of operational CCS. Here we investigate the detectability and environmental impact of leakage from a controlled sub-seabed release of CO 2 . We show that the biological impact and footprint of this small leak analogue (<1 tonne CO 2 d −1 ) is confined to a few tens of metres. Migration of CO 2 through the shallow seabed is influenced by near-surface sediment structure, and by dissolution and re-precipitation of calcium carbonate naturally present in sediments. Results reported here advance the understanding of environmental sensitivity to leakage and identify appropriate monitoring strategies for full-scale carbon storage operations.