Mid-Term Review Meeting, February 13-14, Tutzing Seismic wave Propagation and Imaging in Complex media: a European network JEAN BATTAGLIA Experienced Researcher (postdoc) Host Institution: University Federico II, Naples Place of Origin: Paris, France Appointment Time: July 2004 (until November 2005) Now in Clermont-Ferrand, France (CNRS) Project: Seismicity and 3D velocity structure of the Campi Flegrei (Italy) Task Groups: TG Small Scale Cooperation: Univ. Hamburg (Germany); Univ. College Dublin (Iraland) + University of Nice (France) and University of Chambéry (France)

Mid-Term Review Meeting, February 13-14, Tutzing Project Scope Volcano Seismicity and Volcanic Structures Volcanoes are complexe structures which generate a wide range of seismic signals. General goals of the project: Improving the understanding of the seismicity generated by volcanoes Improving the understanding of volcanic structures Main target: The Campi Flegrei Caldera (southern Italy) and the seismicity during the end of the bradiseismic crisis: relocation of seismicity and tomography. Other targets: Study of volcanic seismicity below Kilauea (collaboration with Hamburg) Testing the amplitude location technique (collaboration with Dublin)

Mid-Term Review Meeting, February 13-14, Tutzing Main Results: Campi Flegrei 1-Precise relative location of the earthquakes Goal: to define the spatial characteristics of the seismogenic structures active during the bradyseismic crises. How: precise relative location based on waveform cross-correlation – requires similar earthquakes. Results: Only 11% of the 870 events can be grouped in multiplets which define streaks diping toward center of caldera. Main result is the absence of similar earthquakes at CF in comparison with other volcanoes (Réunion, Hawaii, Pinatubo) Campi Flegrei: A complex caldera in a highly populated area near Naples. The site of bradiseismic crises characterizd by large ground uplift (1.8 m in ) and seismicity.

Mid-Term Review Meeting, February 13-14, Tutzing Goal: to define the spatial characteristics of the seismogenic structures active during the bradyseismic crises. How: precise relative location based on waveform cross-correlation – requires similar earthquakes. Results: Only 11% of the 870 events can be grouped in multiplets which define streaks diping toward center of caldera. Main result is the absence of similar earthquakes at CF in comparison with other volcanoes (Réunion, Hawaii, Pinatubo) Campi Flegrei: A complex caldera in a highly populated area near Naples. The site of bradiseismic crises characterizd by large ground uplift (1.8 m in ) and seismicity. Main Results: Campi Flegrei 1-Precise relative location of the earthquakes

Mid-Term Review Meeting, February 13-14, Tutzing Main Results: Campi Flegrei 2-Seismic tomography Alternative and complementary solution to improve earthquakes locations is to improve the knowledge of the velocity structure. --> 3D tomographic joint inversion of passive and active arrival times: Vp Vp/Vs ==> complementary data sets provides high resolution Vp and Vs models ● 4529 P and 3286 S travel times from 613 earthquakes (1984) ● P travel times from 1528 shots (SERAPIS experiment, 2001)

Mid-Term Review Meeting, February 13-14, Tutzing Other Targets: Goals and Perspectives Continuation of works started previously (postdocs, PhD) about volcano seismicity through collaborations in SPICE: Study of volcanic seismicity below Kilauea's summit: Moment tensor inversion of a Long Period event recorded in 2001 (Hamburg, Germany) => understand mechanisms of fluid transfer in volcanoes Testing of a location technique based on seismic amplitudes (Battaglia and Aki, 2003): => determine using synthetics the influence of topography, attenuation anomalies... on the locations (Dublin, Ireland) Collaborations to be continued...