http://hdl.handle.net/2122/69 Ricerca nel canale cerca http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/6037 Titolo: Climate change, drought and groundwater availability in southern Italy<br/><br/>Autori: Polemio, M.; CNR-IRPI; Casarano, D.; CNR-IRPI<br/><br/>Curatori: Dragoni, W.; Università di Perugia; Sukhija, B. S.; National Geophysical Research Institute, Hyderabad, India<br/><br/>Abstract: Data for the period 1821 to 2003 from 126 rain gauges, 41 temperature gauges, eight river discharge gauges and 239 wells, located in southern Italy, have been analysed to characterize the effect of recent climate change on availability of water resources, focusing on groundwater resources. Regular data are available from 1921 to 2001. Many analysis methods are used: principal component analysis, to divide the study area into homogenous portions; trend analysis, considering the Mann–Kendall, Student-t and Craddock tests, autocorrelation and cross-correlation analyses, and seasonal, annual and moving-average variables, applying the spatial analysis to each variable with a geographical information system approach. A widespread decreasing trend of annual rainfall is observed over 97% of the whole area. The decreasing trend of rainfall worsens or decreases as mean annual rainfall increases; the spatial mean of trend ranges from 20.8 mm/a in Apulia to 22.9 mm/a in Calabria. The decrease in rainfall is notable after 1980: the recent droughts of 1988–1992 and 1999–2001 appear to be exceptional. On a seasonal basis, the decreasing trend is concentrated in winter; a slight positive trend is observed in summer, the arid season in which the increase is useless as it is transformed into actual evapotranspiration. The temperature trend is not significant and homogeneous everywhere if the temperature increase seems to prevail, especially from about 1980. Net rainfall, calculated as a function of monthly rainfall and temperature, shows a huge and generalized negative trend. The trend of groundwater availability is so negative everywhere that the situation can be termed dramatic for water users, due not only to the natural drop in recharge but also to the increase of discharge by wells to compensate the non-availability of surface water tapped by dams, as a direct effect of droughts. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/2122/5970 Titolo: An Orogenic Model Consistent with Earth Expansion<br/><br/>Autori: Strutinski, C.<br/><br/>Curatori: Barone, M.; Selleri, F.<br/><br/>Abstract: The paper presents the author's view on orogeny, as opposed to the crustal shortening assumption of plate tectonics. It is shown that first order tectonic transport takes place not across but along the strike of orogens. Accordingly orogens are considered to be megashears of the crust. They are of two types, due to their location and specific tectonic environment: equatorial and circum-pacific orogens. As none of them implies subduction, they are consistent with the assumption of an expanding Earth. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/2122/5960 Titolo: Geotectonic hypotheses at the beginning of the 21st century<br/><br/>Autori: Strutinski, C.; Stan, R.; Puste, A.<br/><br/>Curatori: Scalera, G.; Jacob, K.-H.<br/><br/>Abstract: In this contribution to the volume honouring Ott Ch. Hilgenberg the main directions of thought in the field of geotectonics at the beginning of the 21st century are reviewed. However, because of its seminal importance for the geological thinking during most of the last century, the Wegener (continental drift) hypothesis is also included and opens the review. It is followed by the critical presentation of Plate tectonics and the hypotheses of Earth expansion, Surge tectonics and Wrench tectonics. Finally the authors present their own view, which may best be described as shear-belt tectonics or tectonics above asthenocurrents. In their opinion, to expand knowledge on crust and mantle, terms like plate, slab, sliver a.o., that imply rigidity, should be abandoned and replaced by terms used in fluid dynamics (e.g. currents, laminar and turbulent flow, vortices). Wed, 01 Jan 2003 00:00:00 GMT http://hdl.handle.net/2122/5811 Titolo: Pseudotachylytes and Earthquake Source Mechanics<br/><br/>Autori: Di Toro, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Fukuyama, E; Japan<br/><br/>Abstract: Destructive earthquakes nucleate at depth (10 to 15 km), therefore monitoring activefaults at the Earth’s surface, or interpreting seismic waves, yields only limited informationon earthquake mechanics. Tectonic pseudotachylytes (solidified friction-inducedmelts) decorate some exhumed ancient faults and remain, up to now, the only faultrocks recognized as the unambiguous signature of seismic slip. It follows that pseudotachylyte-bearing fault networks might retain a wealth of information on seismic faultingand earthquake mechanics. In this chapter, we will show that in the case of largeexposures of pseudotachylyte-bearing faults, as the glacier-polished outcrops in theAdamello massif (Southern Alps, Italy), we might constrain several earthquake sourceparameters by linking field studies with microstructural observations, high-velocityrock friction experiments, modeling of the shear heating and melt flow, and dynamicrupture models. In particular, it is possible to estimate the rupture directivity and thefault dynamic shear resistance. We conclude that the structural analysis of exhumedpseudotachylyte-bearing faults is a powerful tool for the reconstruction of the earthquakesource mechanics, complementary to seismological investigations. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/2122/5327 Titolo: Seawater intrusion and groundwater quality in the Southern Italy region of Apulia: a multi-methodological approach to the protection<br/><br/>Autori: Polemio, M.; CNR-IRPI<br/><br/>Curatori: Maraga, F.; CNR-IRPI; Arattano, M.; CNR-IRPI<br/><br/>Abstract: Remarkably fast socio-economic development over the past few decades stressed the Region of Apulia’s hydrogeology by originating different hazard sources. Massive groundwater withdrawal increased and aquifers were also increasingly bound to be a sort of ultimate receptacle for domestic and industrial wastewaters. The entire region underwent twofold human-origin pollution caused by saline seawater and chemical-physical intrusion.The importance of impaired natural resources and situation severity called for an approach based on all scientific knowledge available, supplemented by up-to-date investigations on groundwater. The main objective was to identify quality trends availability degradation and groundwater resource risks, by using different GS integrated methodologies and developing management tools, the latter to be simple, quick, affordable and as low cost as possible. The proposed approach was based on groundwater vulnerability assessment and use of an automatic hydrogeology monitoring network, the analysis of rainfall, air temperature, river flow yield time series and, more importantly, piezometric level checks to quantify groundwater availability changes, salinity trend analysis to assess changing seawater intrusion effects, groundwater quality schematic mapping with available chemical- physical laboratory data and multi-parameter logging for fast groundwater quality classification. Each tool used is summarised with the main results ofapplications to Apulia’s aquifers. Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/2122/2590 Titolo: Human fluorosis related to volcanic activity: a review<br/><br/>Autori: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Curatori: Kungolos, A.; University of Thessaly, Greece; Samaras, C.P.; TEI of West Macedonia, Greece; Brebbia, C. A.; Wessex Institute of Technology, U.K.; Popov, V.; Wessex Institute of Technology, U.K.<br/><br/>Abstract: Fluorosis is a widespread disease related to ingestion of high levels of fluorine through water and food. Although sometimes of anthropogenic origin, high levels of fluorine are generally related to natural sources. One of the main sources is represented by volcanic activity, which releases magmatic fluorine generally as hydrogen fluorine through volcanic degassing. For example, Mt. Etna in Italy is considered the greatest point source at the global scale, releasing on average 70 Gg of HF each year. But the impact of fluorine on human health is highly dependent on its chemical state, which means that high rates of release not necessary point to high impacts. The major pathway of magmatic fluorine to humans is in the form of fluoride ion (F-), through consumption of contaminated vegetables and drinking water. Contamination can happen either through direct uptake of gaseous HF or through rainwaters and volcanic ashes. Furthermore hydrogen fluoride, being one of the most soluble gases in magmas, exsolves only partially (< 20%) during volcanic activity. Volcanic rocks thus contain high levels of fluorine, which are transferred to groundwaters through water-rock interaction processes in the aquifers. Large magmatic provinces, like for example the East African Rift Valley, are therefore endemic for fluorosis. Finally a literature review of volcanic related fluorosis is given. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2122/2589 Titolo: Gas hazard: an often neglected natural risk in volcanic areas<br/><br/>Autori: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Curatori: Martin-Duque, J.F.; Universidad Complutense Spain; Brebbia, Carlos A.; Wessex Insitute of Technology U.K.; Emmanouloudis, D.E.; Technological Educational Institute of Kavala Greece; Mander, U.; University of Tartu Estonia<br/><br/>Abstract: Volcanic areas release huge amounts of gases, which apart from having important influences on the global climate could have strong impact on human health. Gases have both acute and chronic effects. Carbon Dioxide and Sulphur gases are the main gases responsible for acute mortality due to their asphyxiating and/or toxic properties. On the contrary Mercury and Radon have important chronic effects respectively for its toxicity and radioactivity. The problem has long been neglected until the “Lake Nyos” catastrophe in 1986, in which about 1700 people were killed by a volcanic CO2 emission, attracted the worldwide attention of the mass media.In this paper we present some studies on gas hazard in three different volcanic systems chosen for their different activity status: Mt. Etna (Italy), characterised by frequent activity with a mean CO2 emission of about 450 kg s-1; Pantelleria island (Italy) at present in quiescent status and a CO2 emission of about 12 kg s-1; and Sousaki (Greece) a recent (Quaternary) but now extinct volcano with a CO2 emission of about 0.6 kg s-1. In all three systems the main problems arise from CO2 emissions while secondary problems are due to SO2 and Hg (Etna), H2S (Sousaki) and Rn (Pantelleria). Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2122/2413 Titolo: Space-time combined correlation between earthquakes and a new, self-consistent definition of aftershocks<br/><br/>Autori: De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Loreto, V.; ”La Sapienza” University, Physics Department, and INFM, Center for Statistical Mechanics and Complexity, Roma, Italy; Pietronero, L.; ”La Sapienza” University, Physics Department, and INFM, Center for Statistical Mechanics and Complexity, Roma, Italy; Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Bhattacharyya, P.; Chakrabarti, B.<br/><br/>Abstract: Seismicity is recognized to be a complex natural phenomenon either in space,time and energy domains: earthquakes occur as a sudden energy release aftera strongly variable time period of stress accumulation, in locations not deterministicallydefined, with magnitude range spanning over several orders. Butseismicity is certainly not a pure random process: spatial locations of eventsclearly display correlations with tectonic structures at all scales (from platesborders to small faults settings); on the other hand time evolution is clearlylinked with strongest shocks occurrence and energy distribution displays hierarchicalfeatures. Although it is still not possible to propose deterministicmodels for earthquakes, well established statistical relations constrain seismicityunder very specific and intriguing relations. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2122/2290 Titolo: On the mechanical work absorbed on faults during earthquake ruptures<br/><br/>Autori: Cocco, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Spudich, P.; U.S.Geological Survey, Menlo Park, California, USA; Tinti, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Abercrombie, R.; McGarr, A.; Kanamori, H.; Di Toro, G.<br/><br/>Abstract: In this paper we attempt to reconcile a theoretical understanding of the earthquake energybalance with current geologic understanding of fault zones, with seismological estimates offracture energy on faults, and with geological measurements of surface energy in fault gouges.In particular, we discuss the mechanical work absorbed on the fault plane during thepropagation of a dynamic earthquake rupture. We show that, for realistic fault zone models,all the mechanical work is converted in frictional work defined as the irreversible workagainst frictional stresses. We note that the eff γ of Kostrov and Das (1988) is zero for crackslacking stress singularities, and thus does not contribute to the work done on real faults. Faultshear tractions and slip velocities inferred seismologically are phenomenological variables atthe macroscopic scale. We define the macroscopic frictional work and we discuss how it ispartitioned into surface energy and heat (the latter includes real heat as well as plasticdeformation and the radiation damping of Kostrov and Das). Tinti et al. (2005) defined andmeasured breakdown work for recent earthquakes, which is the excess of work over someminimum stress level associated with the dynamic fault weakening. The comparison betweengeologic measurements of surface energy and breakdown work revealed that 1-10% ofbreakdown work went into the creation of fresh fracture surfaces (surface energy) in largeearthquakes, and the remainder went into heat. We also point out that in a realistic fault zonemodel the transition between heat and surface energy can lie anywhere below the slipweakening curve. Wed, 01 Nov 2006 00:00:00 GMT http://hdl.handle.net/2122/2289 Titolo: Il quadro sismotettonico del grande terremoto del 1905<br/><br/>Autori: Tiberti, M. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Fracassi, U.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Valensise, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Guerra, I.; Savaglia, A.<br/><br/>Abstract: La storia della Calabria è una storia lunga – molto più lunga di quanto qualunque essere umano possaimmaginare, aggiungeremmo noi geologi – di grandi e piccoli terremoti. Catastrofi improvvise e catastrofiparzialmente annunciate, terremoti improvvisi e isolati e sequenze interminabili che sembravano non volerlasciare in piedi nulla di questa regione.Lo spaventoso livello di sismicità della Calabria, di cui qualunque calabrese è testimone almenoindiretto, è oggi quantomeno ben accertato da ricerche sempre più specialistiche e dettagliate. Due deglielementi fondamentali per descrivere la sismicità calabrese consistono nello studio dei terremoti del passato enello studio della geologia e tettonica di questa regione, riconosciuta da sempre come uno dei luoghimaggiormente attivi di tutto il Mediterraneo. Questi elementi confluiscono in modelli di pericolosità sismica(Gruppo di Lavoro MPS, 2004; fig. 1), che puntualmente fotografano una propensione di questa terra a dareterremoti più forti e più frequenti di quanto non avvenga in qualunque altra zona della penisola.Questa relazione tenta di tratteggiare sinteticamente questa forte propensione alla sismicità,muovendosi tra le caratteristiche geologiche della Calabria e la sua poco invidiabile storia sismica. Larelazione si avvale di risultati di ricerche recenti e recentissime, condotte sia presso l’Istituto Nazionale diGeofisica e Vulcanologia (INGV), sia dalla comunità sismologica nazionale che fa riferimento alleuniversità. La relazione privilegia ampiamente il materiale iconografico basato su tali ricerche. Per ulterioriapprofondimenti si raccomandano i lettori di consultare il sito Internet dell’INGV (www.ingv.it), che nellesue pagine interne offre numerosissime informazioni di facile accessibilità e comprensione. Sun, 01 Jan 2006 00:00:00 GMT