IAVCEI 2013 Scientific Assembly - July 20 - 24, Kagoshima, Japan
Forecasting Volcanic Activity - Reading and translating the messages of nature for society

1W_1E-P19

Date/Time: July 21 Poster

GEOCHEMICAL EXPLORATION FOR GEOTHERMAL RESOURCES AT THE SE ZONE OF
GRAN CANARIA ISLAND (ATIDAMA MINING GRID), CANARY ISLANDS.
Fatima Rodriguez1 , Nemesio Perez2 , Pedro Hernandez2 , Raul Hidalgo3 , Eleazar Padron2 , Gladys
Melian2 , Dacil Nolasco2 , German Padilla2 , Jose Barrancos2 , Samara Dionis1 , Inigo Hernandez1 , David
Calvo1 , Cayetano Guillen1
1Instituto Volcanologico de Canarias, Spain, 2 Instituto Tecnologico y de Energias Renovables, Spain,
3
Petratherm Hispania s.l., Spain
E-mail: fatima@iter.esVery few efforts have been done to date in the Canary Islands to develop the potential geothermal energy resourcesin the archipelago. Between seventies and nineties, the Geological Survey of Spain performed intense researchon geothermal resources in the country due to the oil crisis of the 70s. Later geothermal research declined sharplyand only a few projects on geothermal resources were active in Spain from 1994 to 2006, compared with the many
projects carried out during the previous two decades. This overall picture has changed dramatically in recent yearsand geothermal has become a new source of scientific research activity. In 2011 ITER, University of La Laguna,PETRATHERM Spain and the University of Barcelona started a joint research project (GEOTHERCAN), aimed todevelop an experimental study of 3D models to characterize geothermal reservoirs in the subsurface of Tenerife,
Gran Canaria and La Palma (Canary Islands), which enables further development of geothermal energy in theArchipelago. The multidisciplinary approach of this project, composed by different methodologies and techniques(geochemical, geophysical, and geological) allow us to address the definition of the geothermal potential in theCanary Islands under the framework of this comprehensive and ambitious project.
Under the framework of this project soil gas geochemistry studies will be carried out at different areas of La
Palma, Tenerife and Gran Canaria Islands. In recent years soil gas surveys have become increasingly common ingeoscientific studies. Among the objectives of these studies are the quantification of gas and heat flux from volcanicand geothermal systems and the identification and delineation of active faults. Both topics are of central importanceto investigations of geothermal resources. In this abstract we are presenting the results of a geochemical surveyof soil gases and volatiles that was carried out by ITER during summer 2012 in Atidama area (around 100 km2),
located at the SE of Gran Canaria island. 600 sampling sites were selected to measured soil CO2 efflux, 222Rn
and 220Rn activities, Hg0 and H2S concentrations and soil temperature at 40 cm depth. Soil gas samples werecollected at same depth for chemical analysis (He, H2, N2, CO2, CH4 and Ar). Relatively low CO2 efflux values
were measured, ranging from non-detected up to 52.9 g m-2 day-1, with an average value of 1.9 g m-2 day-1. The
total diffuse CO2 output was estimated in 144 +- 3 t/d. Significant trends observed in the concentration of otherchemical components, suggest the presence of vertical permeability structures in the studied area.

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