HR: 1340h
AN: B23D-1611    [Abstracts]
TI: The Carbon Cycle in Karst Areas: Anomalies of Carbon Dioxide Concentrations in the Underground Atmosphere of Carburangeli Cave (Italy).
AU: * Madonia, P
EM: p.madonia@pa.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa 153, Palermo, 90146, Italy
AU: Bellanca, A
EM: bellanca@unipa.it
AF: Dipartimento CFTA, Università di Palermo, Via Archirafi 36, Palermo, 90100, Italy
AU: Di Pietro, R
EM: r.dipietro@legambienteriserve.it
AF: Legambiente Comitato Regionale Siciliano, Gestione Riserve Naturali, Via Agrigento 67, Palermo, 90141, Italy
AU: Francofonte, V
EM: v.francofonte@pa.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa 153, Palermo, 90146, Italy
AU: Mirabello, L
EM: bellanca@unipa.it
AF: Dipartimento CFTA, Università di Palermo, Via Archirafi 36, Palermo, 90100, Italy
AU: Mastrolia, A
EM: a.mastrolia@pa.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa 153, Palermo, 90146, Italy
AB: The Carburangeli Cave is a small underground environment, protected by a natural reserve, located within a limestone karst area, very close to the ground surface, in the surroundings of the city of Palermo, on the northern coast of Sicily (Italy). Between August 2006 and August 2007 hourly measures of external air temperature, rainfall amount, underground air temperature and static carbon dioxide concentrations and dropping waters amount have been carried out, together with monthly sampling and chemical analysis of underground waters circulating inside the cave. Chemical analyses showed very high concentrations of bicarbonates and calcium, highlighting a strong interactions between infiltrating waters, soil and bedrocks, despite the very shallow hydrologic circuit. Excess CO2 in infiltrating waters is released in the cave atmosphere, as testified by the very high concentrations (more than 2%) measured especially during periods characterized by the block of air circulation between the underground environment and the external atmosphere, on their own due to density differentials induced by the different thermal regimes. The simultaneous measurements of rainfall and dropping waters amounts allowed the evaluation of the infiltration response under different rainfall dynamics, highlighting how under elevated rain rate no significant infiltration takes place, despite the very high permeability typical of karst areas. The high concentrations of carbon species found in infiltrating waters, also in the very shallow circuit of Carburangeli Cave, evidence how karst areas play a very important role as a CO2 sink, although fixation of carbon dioxide could be less efficient under a scenario of more intense rainfalls and higher air temperatures.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1630 Impacts of global change (1225)
DE: 1655 Water cycles (1836)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting