Complex data interpretation for the Eolian volcanic province

The geological environment in southern Italy poses a high risk due to the vicinity of active volcanoes to densely populated areas. In the last years several scientific investigations have been carried out in Italian volcanic areas but, generally, the results have been interpreted as independent experiments and not by a multidisciplinary integrated approach. From the synthesis of the status of research for the Vulcano and Lipari islands, it clearly emerges that an integrated interpretation of all available geoscientiffic results does not exist up to date. Therefore the aim of the proposed projeet is to develop, in a case study, a geo-structural and dynamic model, deseribing the active volcanic system of the Vulcano-Lipari area (Eolian Islands, Sicily), based on a complex interpretation of many different data (including geophysical-, geological-, geochemical-, drilling- data). Additionally a complex airborne geophysical survey will be conducted to gain overview on the regional pattern of potential field data as a basis for further interpretation. The interpretation task will be supported by a multidimensional and multidisciplinary Geographical Information System, that includes the data of the entire area. Consequently, we will use the GIS capabilities to develop and apply different new algorithms for complex data interpretation. Moreover, the relevance of different (potential field geo-) physical parameters, that are currently not used for monitoring in volcanic areas as common practice, will be evaluated on their usability in acting as indicators of changing volcanic activity in that region as the base to set up monitoring networks in the frame of follow-up projects. As a final result this projeet will produce an adequate data platform based on a reliable database and data analysis visualisation tools, to assist effective planning and co-ordination of future scientific research in that area.

The Aeolian Islands are an active volcanic province in the Southern Tyrrhenian Sea north of Sicily. Although many geophysical, geologic and geochemical investigations have been performed in this region, no integrating concept of both the static setting and the dynamic processes acting within the system has been developed in the past. Thus, one primary goal of the COMVOLC project was to set up a geographic information system (GIS) that incorporates all the knowledge that has been assembled about the Aeolian Islands region and the Vulcano-Lipari volcanic complex in particular, in order to provide a data basis for joint analysis and complex interpretation of results provided by different scientific fields. Apart from the design of the GIS, several field campaigns including multi- parameter airborne surveys, multi-electrode geoelectric profiles, ground magnetic, rock susceptibility and radiometric surveys have been conducted to improve the knowledge of regions where no or only limited data have been performed. Linear inversion and forward modeling of airborne magnetic data has been used to develop a model of magnetization of the rocks composing the Vulcano-Lipari complex from the very surface to the volcanic basement. This is possible since anomalies in the Earth`s magnetic field that are observed in a particular region are directly related to the magnetization of rocks in the respective region. As volcanic rocks usually show large magnetization, magnetic anomalies of large amplitude have been recorded during the airborne surveys. The resulting magnetization model could be compared to other models derived from seismology and gravimetry and gives important insights on the volcanic plumbing system of the Vulcano-Lipari complex. Another important feature of magnetized rocks is that they loose their magnetization when heated to temperatures above the so-called Curiè point. Thus, we will anticipate changes in the magnetic anomaly field when the status of the volcanic system changes in such a way that rocks are heated above the Curié point. Airborne magnetic data recorded in a two years interval have been analyzed and compared to recognize such temporal changes in the magnetic anomaly field, showing some distinct variations on Vulcano Island, i.e. a dynamic magnetic model. Both the static and dynamic magnetic models provide valuable information on the overall setup and changes within the volcanic system. For more local, small scaled variation of the system a geoelectric monitoring system has been developed and installed for test measurements on Vulcano Island. With the use of the geoelectric method changes of the electric resistivity can be recorded and correlated to changes within the local hydrothermal state of the system. Overall the COMVOLC project has significantly increased the knowledge of the Aeolian volcanic province and has developed a innovative methodical approach for the early prediction of changes in the volcanic system.