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To cite this version:Candice Lagny. The emissions of gases from abandoned mines : role of atmospheric pressure changes and air temperature on the surface. Environmental Earth Sciences, Springer Abstract Intrinsic parameters influence abandoned mine gas emissions. Independently of the presence or not of noxious gas in mine voids, meteorological factors influenced directly the gas outflow or inflow. Measurement stations were installed in the exits located in abandoned mines of the iron Lorraine basin, the Lorraine and the North East France coal basins to enhance the gas flow behaviour. Closure methods of the mines and exits from the abandoned mines are quite different. For the first, shafts are associated with adits. Some of them are closed with bars to avoid people entrance into abandoned mine workings but gas flow is enabled. For the second, there are essentially shafts which are secured. Some of them are equipped with a vent to enable outflow of the mine gas in specific conditions. Mine gas parameters were measured. Besides, external parameters like temperature and atmospheric pressure were monitored. Gas flow can be influenced mainly by the temperature difference between external atmosphere and mine workings (in iron mines, which can be considered as an open system) while atmospheric pressure influences gas flow in the coal mines, which can be considered as closed systems. Modelling has confirmed the differential pressure value measured that exceeds friction losses.

International audienceThe METSTOR project offers a methodology to look for potentially interesting CO2 storage areas in France at the initial stage, before the "site selection" step. Our tool, embodied in a Geographic Information System, is based on an interactive map of CO2 storage capacities. Other relevant information layers are included. The geographic layers are complemented with a series of online technical notices. It seems to be the first open online GIS that offers policy makers, businesses and the public at large an integrated access to that necessary information. Our prototype, limited mainly to the Paris Basin, is released online at www.metstor.fr

International audienceStudies were carried out in the iron and coal basins of Lorraine (North-East of France) which indicated that oxygen-depleted air and carbon dioxide was being emitted into built-up areas related to former mine workings. Investigations were carried out to determine the origin of this gas production indicated that carbon dioxide production could be caused by the oxidation of iron sulphide minerals (pyrite and marcasite) and reaction of sulphuric acid with carbonates minerals to produce carbon dioxide gas. These reactions have produced highly mineralised mine water with circum-neutral pH values and a low content of dissolved metals and metalloids. Through a bibliographic study, similar neutral mine drainage has been observed and assumptions were made on the reactions which could take place. A conceptual model is proposed to explain the gas emissions

International audienceINERIS has worked for several years on the characterization of O2-defficient and CO2-enriched gas production and migration processes above a partly flooded, former coal mining area. To understand the origin of this gas production, a borehole 90 meters deep was drilled next to the area of gas emmanation. Several investigations were conducted to improve the understanding of the gas production mechanisms in relation to the presence of water. This paper deals with the results of experiments conducted in situ and tests done in the laboratory. One hypothesis is based on the results obtained: marcasite, which has been observed in rock samples, is oxidized by contact with air that migrates through mining fractures in the rock. CO2 is produced through carbonate dissolution because of the production of acidic fluids in the water. Noxious gas emissions can occur during drops in the atmospheric pressure, leading to gas migration through foundation cracks, allowing CO2 to enter into houses