HR: 1340h
AN: B33A-0238    [Abstracts]
TI: Carbon Dioxide Concentrations in the Atmosphere of Underground Environments as Tracers of Climatic Changes
AU: * Madonia, P
EM: p.madonia@pa.ingv.it
AF: I.N.G.V. Sezione di Palermo, Via Ugo La Malfa 153, Palermo, 90146 Italy
AU: Di Pietro, R
EM: carburangeli@neomedia.it
AF: Legambiente C.R.S. Gestione Riserve Naturali, Via Agrigento 30, Palermo, 90100 Italy
AU: Francofonte, V
AF: I.N.G.V. Sezione di Palermo, Via Ugo La Malfa 153, Palermo, 90146 Italy
AB: Carbon dioxide is often observed in concentrations much higher than in external atmosphere inside underground environments, both of natural (caves) and artificial (galleries) origin. With the aim of evaluating the possible use as a tracer of climatic changes, CO2 static concentrations have been discontinuously monitored since the year 2000 in the atmosphere of the Carburangeli and Santa Ninfa Caves, located in a limestone karst areas near the city of Palermo and in a gypsum karst area in the Belice Valley (Sicily, Italy) respectively. The measurements have been acquired with a portable 0-9999 ppm infrared spectrometer, together with dripping waters rate, air temperature and relative humidity (both continuous and discontinuous measures); free CO2 contents of dripping waters have been determined with titration method. Highest values were recorded in Carburangeli cave, when underground air temperature is colder than external atmosphere: in this case air circulation is blocked and carbon dioxide concentration arises. Very high concentrations of carbon dioxide were recorded also in winter, when hot winds blew from SE. The main source for carbon dioxide has been individuated in the dripping waters, which rate depends on the dynamic of rainfall events. These preliminary data suggests that carbon dioxide concentrations in the underground atmosphere of Carburangeli cave strongly depend on the delicate equilibria between internal and external air temperatures and dripping waters rate, being all these parameters affected by possible climate changes. Atmospheric warming and intensification of rainfalls rate might be traced by variations in the space-time dynamic of carbon dioxide inside the cave.
DE: 3322 Land/atmosphere interactions
DE: 1655 Water cycles (1836)
DE: 1600 GLOBAL CHANGE (New category)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting