FLUID GEOCHEMISTRY INVESTIGATIONS ON THE VOLCANIC SYSTEM OF METHANA


Published: Jan 1, 2007
Keywords:
Αέρια υπεδάφους γεωχημεία υπογείου νερού ροή C02 επικινδυνότητα αερίων
W. D'Alessandro
L. Brusca
K. Kyriakopoulos
M. Margaritopoulos
G. Michas
G. Papadakis
Abstract

An extensive geochemical survey on the fluids released by the volcanic/geothermal system of Methana was undertaken. Characterization of the gases was made on the basis of the chemical and isotopie (He and C) analysis of 14 samples. CO2 soil gas concentration and fluxes were measured on the whole peninsula at more than 100 sampling sites. 31 samples of thermal and cold groundwaters were also sampled and analysed to characterize the geochemistry of aquifers. Anomalies referable to the geothermal system, besides at known thermal manifestations, were also recognized at some anomalous degassing soil site and in some cold groundwater. These anomalies were always spatially correlated to the main active tectonic system of the area. The total CO2 output of the volcanic system has been preliminary estimated in about 0.2 kg s~ . Although this value is low compared to other volcanic systems, anomalous C02 degassing at Methana may pose gas hazard problems. Such volcanic risk, although restricted to limited areas, cannot be neglected and further studies have to be undertaken for its better assessment.

Article Details
  • Section
  • Mineralogy-Petrology-Geochemistry-Economic Geology
Downloads
Download data is not yet available.
References
APHA, AW WA, WEF, 1995. Standard methods for the determination of water and wastewater, (Eaton A.D., Clesceri L.S. and Greenberg A.E. eds.) 19th edition.
Cardellini, C, Chiodini, G., and Frondini, F., 2003. Application of stochastic simulation to C02 flux from soil: Mapping and quantification of gas release, J. Geophys. Res. 108(B9), 2425, doi: 10.1029/2002JB002165
Chiodini, G., and Cioni, R., 1989. Gas geobarometry for hydrothermal systems and its application to some Italian geothermal areas, Appi. Geochem., 4, 465-472.
Chiodini, G., Cioni, R., Guidi, M., Raco, Β., and Marini, L., 1998. Soil C02 flux measurements in volcanic and geothermal areas, Appi. Geochem., 13, 543-552.
D'Alessandro, W., Brusca, L., Kyriakopoulos, K., Rotolo, S., Michas, G., Minio, M., and Papadakis, G., 2006. Diffuse and focused carbon dioxide and methane emissions from the Sousaki geothermal system, Greece, Geophys. Res. Lett., 33, L05307.
Dietrich, V., and Gaitanakis, P., 1995. Geological map of Methana peninsula (Greece), ΕΤΗ Zürich, Switzerland.
Henderson, Y., and Haggard, H.W., 1943. Noxious gases, Reinhold Pub. Co.
Lewicki, J.L., Bergfeld, D., Cardellini, C, Chiodini, G., Granieri, D., Varley, N., and Werner, C, 2005. Comparative soil C02 flux measurements and geostatistical estimation methods on Masaya volcano, Nicaragua, Bull. Volcanol., 68, 76-90.
Makris, J., Papoulia, J., and Drakatos, G., 2004. Tectonic deformation and microseismicity of the Saronikos Gulf, Greece, Bui. Seismol. Soc.Am., 94(3), 920-929.
Nicholson, K., 1993. Geothermal fluids, Springer Verlag, Berlin, 263pp.
Norman, J.M., Garcia, R., and Verma, S.B., 1992. Soil surface C02 fluxes and the carbon budget of a grassland, J. Geophys. Res., 97, 18845-18853.
Pecoraino, G., Brusca, L., D'Alessandro, W., Giammanco, S., Inguaggiato, S., and Longo, M., 2005. Total C02 output from Ischia Island volcano (Italy). Geochem. J. 39, 451-458.
Pe-Piper, G., and Piper, D.J.W., 2002. The igneous rocks of Greece, Bornträger, Berlin. Stothers, R.B., and Rampino, M.R., 1983. Volcanic eruptions in the Mediterranean before A.D. 630 from written and archeological sources, J. Geophys. Res., 88, 6357-6371.
Volti, T.K., 1999. Magnetotelluric measurements on the Methana peninsula (Greece): modeling and interpretation, Tectonophys., 301, 111-132.
Vougioukalakis, G.E., and Fytikas, M., 2005. Volcanic hazards in the Aegean area, relative risk evaluation, monitoring and present state of the active volcanic centers. In Fytikas M. and Vougioukalakis G.E. (eds.) The south Aegean active volcanic arc - Developments in Volcanology 7, 161-183.
Witham, CS., 2005. Volcanic disasters and incidents: A new database, J. Volcanol. Geotherm. Res., 148, 191-233.
Most read articles by the same author(s)