89° Congresso SIMP (Ferrara, 13-15 Settembre 2010)
Total Page:16
File Type:pdf, Size:1020Kb
PLINIUS n. 36, 2010 L’EVOLUZIONE DEL SISTEMA TERRA DAGLI ATOMI AI VULCANI FERRARA 13-15 Settembre 2010 PLINIUS n. 36, 2010 PLENARY LECTURES PLINIUS n. 36, 2010 STROMBOLI, ETNA AND VESUVIUS: EXAMPLES OF VOLCANIC RISKS MANAGED BY DPC C. Cardaci Dipartimento della Protezione Civile - Servizio Rischio Vulcanico, Roma [email protected] Italy’s national territory is exposed to a broader range of natural hazards than other European countries. For this reason, Italy has implemented a coherent, multi-risk approach to civil protection. This approach fully integrates the scientific and technological expertise within a structured system aimed at forecasting natural disasters, providing early warning and immediately managing the emergency. With regard to its delayed time activities, the Department of Civil Protection (DPC) provides strong support to the knowledge of natural hazardous phenomena through a network of Competence Centres (Centres for technological and scientific services). DPC supports research efforts on the assessment of vulnerability and exposure of population, buildings and critical infrastructures to the risks associated with these phenomena. The early warning system for volcanic events, floods, landslides, hydro-meteorological events and forest fires includes prevention activities. It is provided by the DPC on the basis of the network of “Centri Funzionali” (Functional Centres). These centres are in charge of the forecast and assessment of the risk scenarios, in order to provide a multiple support system to the decision makers of the Civil Protection Authorities. The Functional Centres are organized in a network which consists of operative units able to collect, elaborate and exchange any kind of data (meteorological, hydro-logical, volcanic, seismic and so on), and it is supported by selected Competence Centres involved in the analysis of a specific risk. The southern part of Italy has the highest concentration of active volcanoes of entire Europe: Etna, Vesuvius, Phlegrean Fields, Vulcano, Stromboli. More than 2 millions people are exposed to the volcanic risk. Stromboli is characterized by a typical “strombolian” activity, with explosions every 10-20 minutes, and it represents a major attraction for the tourists in the Aeolian archipelago. On the December 30th, 2002, a landslide along the Sciara del Fuoco flank triggered a tsunami that severely affected the Stromboli coasts and reached the other Aeolian islands and the northern part of Sicily, although with lower intensity. Since that catastrophic event the DPC, in cooperation with the scientific community and the local population, funded the improvement of a multiparametric monitoring system and undertook several countermeasures to mitigate the volcanic risk. Nowadays DPC provides a daily bulletin of criticality in order to estimate the impending risk. Etna volcano, with the strong ash emissions of 2002 - 2003 and 2006 eruptions, brought severe problems to the air traffic management, in particular to the Catania international airport (located about 30 km SE of the Mt. Etna). In order to support the local airspace authorities for the air traffic management in case of eruption, DPC daily provides simulation maps of the probable plume direction and ash dispersion every three hours. Due to the extensive urbanization of its surroundings, Vesuvius represents one of the areas with highest volcanic risk in the world. The DPC, through a dedicated expertise Commission, is updating the National Emergency Plan for the Vesuvius, which foresees the total evacuation of the “red area” (about 500.000 people) within 72 hours. In 2006 the Vesuvius emergency plan and its procedures were successfully tested by a European civil protection exercise (M.E.SIM.EX). 255 PLINIUS n. 36, 2010 THE COMPOSITION OF THE TERRESTRIAL PLANETS AND THE EARLY EVOLUTION OF THE EARTH W. McDonough Department of Geology, University of Maryland, College Park, MD (USA) [email protected] The terrestrial planets, as well as the Earth’s Moon and other rocky bodies in the asteroid belt, are differentiated rock and metal mixtures that have been depleted in volatile elements to varying degrees. Compositional models for these bodies assume chondritic proportions of the refractory elements (e.g., Ca, Al, and some 40 trace elements), with no fixed constraint on their absolute concentrations. These bodies are primarily composed of Fe, Mg, Si and O [making up 95% of their mass, with no fixed, chondritic proportions]. Detailed planetary geodesy underpins modeling of the metal to rock ratio and dynamics of the interiors of these bodies. Crucial to modeling planetary compositions are the absolute abundances and the distribution of heat producing elements (i.e., extinct, short-lived isotopes and K, Th and U), the elements that provide the heat that drives convection and volcanism. The early thermal and chemical evolution of the planets was strongly controlled by accretionary growth and post-accretion additions (e.g., late veener). Planetary degassing and heat dissipation is recorded in the volcanic products of these bodies and, in the case of planets, the atmospheric composition. Knowledge gained from developing and constraining the Earth’s compositional models provides important guiding principles that are essential for advancing compositional models for other planets and rocky solar system bodies. Geoneutrinos, which are anti-neutrinos produced during beta-decay in the U and Th decay chains, have now been detected by neutrino detectors, and afford an independent means of estimating the Earth’s heat producing element concentrations. Recent results from the KamLAND and Borexino geoneutrino experiments are coincident with geochemical models of Th and U in the Earth. These detectors continue to count and, thus, uncertainties will be reduced with time (at present 2 detectors are accumulating data, a 3rd is to come on-line). Geochemical models posit that ~ 40% of the heat producing elements are in the continental crust, with the remainder in the mantle. Although models of core formation allow for the incorporation of heat producing elements, the core contribution of radiogenic heating is considered negligible. The Mantle Urey (Ur) ratio is a measure of the radiogenic heat contribution to the total mantle heat flux and is estimated to be ~ 0.3 from chemical and isotopic data. Such a low mantle Urey ratio is at odds with most parameterized convection models (i.e., Ur = 0.7) for the Earth and thus challenge geophysical models. The geo/cosmochemical and geoneutrino constraints demonstrate that there is a significant contribution to the Earth’s heat budget from the secular cooling of the mantle. 256 PLINIUS n. 36, 2010 THE CHALLENGE OF CLIMATE SCIENCE A. Navarra Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna Centro Euro-Mediterraneo per i Cambiamenti Climatici [email protected] Climate has become one of the hottest issues today, moving from an obscure scientific dispute to the status of a global geopolitical issue, but the concept of climate itself is a sophisticated concept that is not the static, intuitive, idea that we may use in everyday life. The basic mechanisms of climate are regulated by global energy balances and they are the result of complex nonlinear interactions among the several systems participating in the shaping of the Earth climate. The intensity of the non linear interactions generates an intense variability in climate that makes very difficult the detection of small, secular trends. The increase of carbon dioxide and of surface temperatures is now being established as a fact, but the attribution of the temperature rise to carbon dioxide increases is a complex decision process. We cannot perform crucial experiments in climate science and we have to rely on a combination of numerical experiments and consensus among experts to reach provisional explanations. Nevertheless, this process results in the accumulation of knowledge and we will have to live with the idea that this is the way in which climate science progresses. 257 PLINIUS n. 36, 2010 CRITICAL ISSUES IN THE MANAGEMENT OF VOLCANIC CRISIS M. Rosi Dipartimento di Scienze della Terra, Università di Pisa [email protected] Volcanic crisis of the past four decades have represented a major challenge to worldwide society. Volcanic events and unrest crisis (not followed by eruption), with some significant consequence on human society have occurred at a rate of several events per year at global scale. A significant part of them have occurred near settled areas either producing victims and or relevant economic losses. Impact of eruptions has been generally severe on inhabited areas located in the immediate surroundings of active volcanoes. However, mudflows and ash fall have severely hit human communities even at tens of kilometres from source volcanoes. A much broader impact has resulted both on air traffic and airport functionality from the injection in the atmosphere of volcanic gas, aerosols and ash. The latter problem has greatly expanded over the last four decades as a result of worldwide escalation of flight transportation. Volcanic crisis vary significantly depending on size and violence of volcanic events, duration of the crisis, impacts on society (e.g. casualties, damage to buildings and critical facilities, economic losses) and different degrees of preparedness to deal with emergencies by local people, civil protection and public authorities. Size and intensities of post-1980 volcanic events have spanned from trivial