HR: 14:15h
AN: V33C-02 INVITED     [Abstracts]
TI: Volcanic hazards maps of the restless Campi Flegrei caldera in the Neapolitan area (Italy)
AU: * Orsi, G
EM: orsi@ov.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano, Via Diocleziano 328, Naples, 80124, Italy
AU: Di Vito, M A
EM: divito@ov.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano, Via Diocleziano 328, Naples, 80124, Italy
AU: Dell'Erba, F
EM: dellerba@ov.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano, Via Diocleziano 328, Naples, 80124, Italy
AU: Quaglino, M
EM: quaglino@ov.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano, Via Diocleziano 328, Naples, 80124, Italy
AU: Marzocchi, W
EM: marzocchi@bo.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti 12, Bologna, 40128, Italy
AU: Sandri, L
EM: sandri@bo.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti 12, Bologna, 40128, Italy
AU: Selva, J
EM: selva@bo.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti 12, Bologna, 40128, Italy
AB: Volcanic hazards maps for the restless Campi Flegrei caldera have been constructed using stratigraphical, volcanological, structural and petrological data, and statistical analyses. Although only 4 out of 70 eruptions of the past 15 ka were effusive, it cannot be excluded that the next eruption will be effusive. The past explosive eruptions can be grouped in low-, medium-, and high-magnitude events. A future explosive eruption could likely occur in the north-eastern sector of the caldera floor that is under a tensile stress regime, when the ongoing deformation will generate mechanical failure of the rocks. A vent could open also in the western sector, at the intersection of two fault systems contemporaneously activated, as happened in the last eruption at Monte Nuovo, in 1538 AD. The eruption could likely be preceded by precursors apparent to the population, such as ground deformation, seismicity and increase in gas emissions. It will probably alternate between magmatic and phreatomagmatic phases with the generation of tephra fallout, and dilute and turbulent pyroclastic currents. In order to perform a zoning of the territory in relation to the expected volcanic hazards, we have constructed hazards maps in which the areas at variable probability of opening of a new vent, those which could be affected by variable load of fallout deposits, and those over which pyroclastic currents could flow, are delimited. The areas in which a vent could likely open have been defined on the basis of the dynamics of the ongoing deformation of the caldera floor, and of a statistical analysis of critical elements. To construct the fallout hazard map we have used the frequency of deposition of fallout beds, the frequency of load on the ground by tephra fallout and the direction of dispersal axes of the deposits of the last 5 ka, and the limit load of collapse for the variable types of roof construction. The pyroclastic-current hazard map has been based on the areal distribution and frequency of the pyroclastic-current deposits of the last 5 ka.
DE: 8010 Fractures and faults
DE: 8428 Explosive volcanism
DE: 8440 Calderas
DE: 8486 Field relationships (1090, 3690)
DE: 8488 Volcanic hazards and risks
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly