ARMA based approaches for forecasting the tuple of wind speed and direction

. The possible emplacement of pyroclastic fall and flow products from Campi Flegrei and Somma-Vesuvio represents a threat for the population living in Napoli city. For this area, the volcanic hazard was always partially investigated to define the hazard related to the Campi Flegrei or to the Somma-Vesuvio activity one at a time. A new volcanic hazard and risk assessment, at the municipality scale, as a vital tool for decision-making about territorial management and future planning, is presented here. In order to assess the hazard related to the explosive activity of both sources, we integrated the results of field studies and numerical simulations, to evaluate the future possibility for Napoli to be hit by the products of an explosive eruption. This is defined for the Somma Vesuvio central volcano through the sum of "field frequency" based on the thickness and distribution of past deposits (Lirer et al., 2001), and for the Campi Flegrei volcanic field by suitably processing simulated events based on numerical modelling (Alberico et al., 2002; Costa et al., 2009). Aiming at volcanic risk assessment, the hazard areas were joined with the exposure map, considered for our purposes as the economical value of artefacts exposed to hazard. We defined four risk classes, and argued that the medium and low-very low risk classes have the largest extent in Napoli municipality, whereas only few zones located in the eastern part of the city and in the westernmost coastal area show a high risk, owing to the correspondence of high economical value and high hazard.

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Volcanic hazard and risk assessment in a multi-source volcanic area: the example of Napoli city (Southern Italy)

Predictive model of yaw error in a wind turbine

In order to zone the territory of Campania Region (southern Italy) with regard to the hazard related to future explosive activity of Somma-Vesuvio, Campi Flegrei, and Ischia Island, we drew a multi-source hazard map for tephra and pyroclastic flows. This map, which merges the areas possibly endangered by the three volcanic sources, takes into account a large set of tephra fall and pyroclastic flow events that have occurred in the last 10 ka. In detail, for fall products at Campi Flegrei and Somma-Vesuvio we used the dispersal of past eruption products as deduced by field surveys and their recurrence over the whole area. For pyroclastic flows, the field data were integrated with VEI = 4 simulated events; about 100 simulations sourcing from different points of the area were performed, considering the different probability of vent opening. The spatial recurrence of products of both past eruptions and simulated events was used to assign a weight to the area endangered by the single volcanic sources. The sum of these weights in the areas exposed to the activity of two sources and/or to different kinds of products was used to draw a hazard map, which highlights the spatial trend and the extent of the single equivalent classes at a regional scale. A multi-source risk map was developed for the same areas as the graphic result of the product of volcanic hazard and exposure, assessed in detail from a dasymetric map. The resulting multi-source hazard and risk maps are essential tools for communication among scientists, local authorities, and the public, and may prove highly practical for long-term regional-scale mitigation planning.

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Hazard and risk assessment in a complex multi-source volcanic area: the example of the Campania Region, Italy

The advection–diffusion model TEPHRA2 has been used in conjunction with the downhill simplex method (DSM) and one-at-a-time (OAT) inversion methods to reconstruct the eruption conditions and seasonality consistent with the deposit patterns from the Bronze Age (‘Minoan’) eruption of Santorini. We investigated three datasets representing different depositional environments (proximal terrestrial, distal terrestrial and deep-sea core), in order to determine source conditions such as plume height, erupted mass and grain-size and recreate the tephra fall deposit from the Plinian, co-ignimbrite and combined eruptive phases. The results of the DSM and OAT method agreed adequately well with each other for erupted mass, plume height and grain-size distribution. Both approaches were able to successfully recreate the Plinian deposit but estimating conditions that created the co-ignimbrite and deep-sea core dataset were less successful. The reduced agreement is the result of the low quantity (6 to 28 deposit points) and quality (inconsistent deposit depths at localities adjacent to each other) of the datasets, and the different dynamics between co-ignimbrite and Plinian columns, with the former not well represented in the model. Different sampling methods between archaeological and volcanological disciplines and post-depositional processes which have acted on the tephra deposits since the Bronze Age can explain the discrepancy between these computed and observed deposits. The seasonality of the Minoan eruption was investigated by using seasonal wind profiles for winter, spring, summer and autumn. We find that the Bronze Age eruption of Santorini is likely to have during the spring and summer months with a main dispersal axis aligned East. Crete would have received very little ash fall, and the eruption would not have caused much disruption to the life of the inhabitants of the island.

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P. Daniele

Papers

Applications of the PUFF model to forecasts of volcanic clouds dispersal from Etna and Vesuvio