Mapping and quantifying CO2 leakage using the Ground CO2 Mapper

The standard method for mapping and quantifying CO2 leakage flux from the ground surface to the atmosphere involves performing numerous point flux measurements using the accumulation chamber technique and then applying geostatistical interpolation to infer spatial distribution and estimate total mass transfer. Monte Carlo simulations using the program MCFlux have recently demonstrated, however, that uncertainty in the resultant estimate can be large if the chosen sample spacing is insufficient to capture the spatial complexity and size distribution of the leakage anomalies. In an effort to reduce this uncertainty we have developed a new tool, called the Ground CO2 Mapper, that rapidly measures the concentration of CO2 at the ground surface as a proxy for flux. Recently published results have illustrated the capabilities of the Mapper in terms of sensitivity and spatial resolution, as well as possible influencing parameters such as wind strength. The present work examines the potential of combining Mapper results with point flux measurements (using multivariate geostatistics) to improve data interpretation, with the MCFlux program being used once again to assess uncertainty in the final estimates

Gas migration along fault systems and through the vadose zone in the Latera caldera (central Italy): Implications for CO2 geological storage

A clear and detailed understanding of gas migration mechanisms from depth to ground surface is fundamental to choose the best locations for C02 geological storage sites, to engineer them so that they do not leak, and to select the most appropriate monitoring strategy and tools to guarantee public safety. Natural test sites (or "natural analogues") provide the best opportunity to study migration mechanisms, as they incorporate such issues as scale, long-time system evolution, and interacting variables that cannot be adequately addressed with laboratory studies or computer models. To this end the present work examines the migration to surface of deep, naturally produced C02 along various buried and exposed faults in the Latera caldera (central Italy) by integrating structural geology and near-surface gas geochemistry surveys. Results show how gas migration is channelled along discrete, high -permeability pathways within the faults, with release typically occurring from spatially restricted gas vents. Size, distribution, and strength of these vents appear to be controlled by the evolution and deformation style of the fault, which is in turn linked to the rheology of the lithological units cut by the fault. As such gas migration can change drastically along strike. Gas migration in the vadose zone around these vents is also discussed, focussing on how the physical-chemical characteristics of various species (C02, CH4, and He) control their spatial distribution and eventual release to the atmosphere. (c) 2008 Elsevier Ltd. All rights reserved

Continuous monitoring of natural CO2 emissions near Rome: lessons for low-level CO2 leakage detection

Continuous monitoring has been carried out at a fluvial flood-plain site near Rome for over a year. There is a mix of biogenic CO2 and deep geogenic CO2 at the site at relatively low concentrations and fluxes compared with other natural CO2 seepage sites studied previously. Factors such as temperature and soil moisture clearly affect the CO2 concentration and flux and seasonal and diurnal influences are apparent. Statistical approaches are being used to try to define these relationships and separate out the two gas components, which would be necessary in any quantification of leakage from CO2 storage

Relationships between geogenic radon potential and gamma ray maps with indoor radon levels at Caprarola municipality (central Italy)

Exposures to relatively high indoor radon (222Rn) levels represents a serious public health risk because Rn is associated with lung cancer (Darby et al., 2001; WHO, 2009; Oh et al., 2016; Sheen et al., 2016). The risk is high because radon, and its short-lived decay products in the atmosphere, contributes for about 60% of the total annual effective dose (UNSCEAR, 2000; WHO, 2009). Cancer risk is increased by smoking being almost 9 times higher than the risk to non-smokers exposed to similar levels (EPA, 2009). Due to these reasons, it is very important to assess the indoor exposure of public to radon and their daughters. Rn is a natural ubiquitous gas and its abundance is mainly controlled by the geology, and in particular by the soil and rock content of its parent nuclide (238U). Furthermore, bedrock characteristics (i.e. permeability and porosity) and also fault activity can affect the amount of Rn released in the ground (Ciotoli et al., 2007; Barnet et al., 2018). As such, in conditions of permeable and/or fractured bedrock and high uranium content, high indoor radon concentrations are expected (Bossew and Lettner, 2007; Gruber et al., 2013; Cinelli et al., 2015; Ielsch et al., 2017; Ciotoli et al., 2017). A non-natural contribution that controls the indoor Rn levels is home construction type and building materials (Vauptic et al., 2002; Appleton, 2007). Additionally, meteorological factors, such as wind, temperature and humidity, can affect the rate of Rn entry into the buildings (Porstendörfer et al., 1994; Miles et al., 2005; Schubert et al., 2018). In this work, we propose a new geospatial technique to construct the geogenic radon potential (GRP) map of the Caprarola municipality (northern Lazio, central Italy) characterized by recent (about 100 Kyr) volcanic deposits with high content in radon parent nuclides (Ciotoli et al., 2017). GRP map has been obtained by using Empirical Bayesian Kriging Regression (EBKR) technique with soil gas radon, as the response variable, and a number of proxy variables (i.e. content of the radiogenic parent nuclides, the emanation coefficient of the outcropping rocks, the diffusive 222Rn flux from the soil, the soil-gas CO2 concentration, the Digital Terrain Model (DTM), the permeability of the outcropping rocks and the gamma dose radiation of the shallow lithology. Furthermore, possible relationships between predicted soil radon values (i.e. GRP) and gamma radiation distribution with the indoor concentrations measured in private and public buildings has been investigated, respectively. The obtained results confirm that GRP maps provide the local administration of a useful tool for land use planning and that, the mapping of gamma emission, allows to a fast and effective evaluation of indoor radon hazard because it is mainly influenced by the building materials rather than other anthropic controls

Comparison of radon mapping methods for the delineation of radon priority areas - an exercise

Background: Many different methods are applied for radon mapping depending on the purpose of the map and the data that are available. In addition, the definitions of radon priority areas (RPA) in EU Member States, as requested in the new European EURATOM BSS (1), are diverse. Objective: 1) Comparison of methods for mapping geogenic and indoor radon, 2) the possible transferability of a mapping method developed in one region to other regions and 3) the evaluation of the impact of different mapping methods on the delineation of RPAs. Design: Different mapping methods and several RPA definitions were applied to the same data sets from six municipalities in Austria and Cantabria, Spain. Results: Some mapping methods revealed a satisfying degree of agreement, but relevant differences were also observed. The chosen threshold for RPA classification has a major impact, depending on the level of radon concentration in the area. The resulting maps were compared regarding the spatial estimates and the delineation of RPAs. Conclusions: Not every mapping method is suitable for every available data set. Data robustness and harmonisation are the main requirements, especially if the used data set is not designed for a specific technique. Different mapping methods often deliver similar results in RPA classification. The definition of thresholds for the classification and delineation of RPAs is a guidance factor in the mapping process and is as relevant as harmonising mapping methods depending on the radon levels in the area.Funding: This work is supported by the European Metrology Programme for Innovation and Research (EMPIR), JRPContract 16ENV10 MetroRADON (www.euramet.com). The EMPIR initiative is co-funded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States

Indagini geofisiche e geochimiche di un sinkhole in formazione nell’area di Guidonia (Lazio)

The Plio-Quaternary Acque Albule Basin is already known for the occurrence of sinkholes; since the spring 2014, it has been ongoing the study of an active subsidence process, which formed a depressed area near the Guidonia village. During the last year, the phenomenon has become more intense giving rise to two collapses along the eastern rim of the depression. Thus, geophysical and geogeochemical investigation campaigns started in order to understand the genesis and evolution of the phenomenon. Survey results allowed a geological and structural characterization, showing the presence of “travertino” at the depression margins and its absence therein. It has been recognized, by the geophysics, features with NW-SE and NNE-SSW direction ascribable to a possible depression fracturing and consistent with regional structural trends. Thus, it has been possible to plan and perform geognostic investigation consisting in two drillings aimed to define the stratigraphy of the marginal and inner part of the depression.Published7 - 162TR. Ricostruzione e modellazione della struttura crostaleJCR Journa

On harmonization of radon maps

Background: Maps are important tools for geographic visualization of the state of the environment with respect to resources as well as to hazards. One of the hazards is indoor radon (Rn), believed to be the most important cause of lung cancer after smoking. In particular, as part of Rn mitigation policy and in compliance with the European Basic Safety Standards, EU Member States have to declare areas with elevated indoor Rn concentration levels. However, as this is done by national authorities according to individually chosen criteria, the resulting maps are not easily comparable.Objective: We aim to identify causes for the lack of compatibility of maps and suggest solutions for the problem.Design: This study draws from experiences of recent research projects, literature, and personal involvement of the authors in the discussions.Results: An overview is given on causes and effects of lack of compatibility between maps. Existing experiences are reported. Options for defining lack of compatibility and for identifying it are discussed. Methods for harmonization, that is, remediating lack of compatibility, are addressed.Conclusions: The difficulty of harmonization increases with the aggregation level of data which support maps. Harmonization is the more difficult, the higher aggregated the data are which support maps. In particular, harmonization of radon priority area maps is technically non-trivial, and theoretical efforts as well as practical tests will have to be undertaken.Special issue - European Radon Week 202

Overview of Radon Flux Characteristics, Measurements, Models and Its Potential Use for the Estimation of Radon Priority Areas

Radon flux measurements provide information about how much radon rises from the ground toward the atmosphere, thus, they could serve as good predictors of indoor radon concentrations. Although there are many different mapping methods with many different input data, radon flux data are generally missing and are not included for the delineation of radon priority areas (RPA). The aim of this literature review is to investigate to what extent radon flux was used, or could be used, for the delineation of RPAs. Numerous factors influencing radon flux were identified, but quantifying their contribution to radon flux measurement still remains a challenge. Different methods and measuring devices were used for the determination of radon flux, thus it is necessary to identify possible inconsistencies in order to harmonise different radon flux measurements. Due to the complexity of radon flux measurements, only two countries were identified to have performed national surveys on outdoor radon, which were of much smaller scale compared to those on indoor radon. A positive correlation between radon flux and radon quantities, such as radon in soil gas and indoor radon, indicates that radon flux could be used as an input parameter for the estimation of RPA. By reviewing radon flux models, it was concluded that up-to-date modelled radon flux maps have reached excellent spatial resolution and will be further improved, hence, they could serve as an input for the estimation and delineation of RPA

The consolidated European synthesis of CH4 and N2O emissions for the European Union and United Kingdom : 1990-2019

Funding Information: We thank Aurélie Paquirissamy, Géraud Moulas and the ARTTIC team for the great managerial support offered during the project. FAOSTAT statistics are produced and disseminated with the support of its member countries to the FAO regular budget. Annual, gap-filled and harmonized NGHGI uncertainty estimates for the EU and its member states were provided by the EU GHG inventory team (European Environment Agency and its European Topic Centre on Climate change mitigation). Most top-down inverse simulations referred to in this paper rely for the derivation of optimized flux fields on observational data provided by surface stations that are part of networks like ICOS (datasets: 10.18160/P7E9-EKEA , Integrated Non-CO Observing System, 2018a, and 10.18160/B3Q6-JKA0 , Integrated Non-CO Observing System, 2018b), AGAGE, NOAA (Obspack Globalview CH: 10.25925/20221001 , Schuldt et al., 2017), CSIRO and/or WMO GAW. We thank all station PIs and their organizations for providing these valuable datasets. We acknowledge the work of other members of the EDGAR group (Edwin Schaaf, Jos Olivier) and the outstanding scientific contribution to the VERIFY project of Peter Bergamaschi. Timo Vesala thanks ICOS-Finland, University of Helsinki. The TM5-CAMS inversions are available from https://atmosphere.copernicus.eu (last access: June 2022); Arjo Segers acknowledges support from the Copernicus Atmosphere Monitoring Service, implemented by the European Centre for Medium-Range Weather Forecasts on behalf of the European Commission (grant no. CAMS2_55). This research has been supported by the European Commission, Horizon 2020 Framework Programme (VERIFY, grant no. 776810). Ronny Lauerwald received support from the CLand Convergence Institute. Prabir Patra received support from the Environment Research and Technology Development Fund (grant no. JPMEERF20182002) of the Environmental Restoration and Conservation Agency of Japan. Pierre Regnier received financial support from the H2020 project ESM2025 – Earth System Models for the Future (grant no. 101003536). David Basviken received support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (METLAKE, grant no. 725546). Greet Janssens-Maenhout received support from the European Union's Horizon 2020 research and innovation program (CoCO, grant no. 958927). Tuula Aalto received support from the Finnish Academy (grants nos. 351311 and 345531). Sönke Zhaele received support from the ERC consolidator grant QUINCY (grant no. 647204).Peer reviewedPublisher PD