559 research outputs found
Vesuvio civil protection exercise MESIMEX: survey on volcanic risk perception.
In October 2006 the European Civil Protection Exercise MESIMEX
(Somma Vesuvio Mesimex – Major Emergency SIMulation Exercise) on
volcanic risk took place at Vesuvio, promoted by Campania Region and
coordinated by the Italian Civil Protection Department. The exercise was
focused on the preparedness phase for a major volcanic emergency in the
area of Vesuvio. An evacuation of a sample of 1800 inhabitants from the
Vesuvio Red Zone was also tested during the drill because the emergency
plan ensures the complete evacuation of the population from the higher
risk zone before the onset of the eruption. During that event a survey on
volcanic risk perception was carried out on the evacuated population in
order to compare the results with the ones coming from a previous similar
survey, using the same questionnaire, carried out on a wider sample
of residents in the Vesuvio Red Zone few months before MESIMEX exercise.
The aim was to point out any differences in population’s attitude towards
volcanic risk after having received detailed information on the
emergency plan and on the hazards and risk related to the reactivation of
Vesuvio, and experiencing the exercise. 463 questionnaires were distributed
to the population evacuated from the 18 municipalities of the Red
Zone and participating to the exercise. Main results in comparing data
from MESIMEX survey with the Vesuvio previous one, put in evidence
how the general level of Vesuvio residents’ trust remains quite low, indicating
that a continuous and effective effort has to be done by both scientific
community and Civil Protection Department. Particular attention
should be paid in education and outreach activities and in involving people
in risk mitigation procedures, also through more frequent exercises
Localizzazione probabilistica 3D (NonLinLoc) applicata all’area calabro-peloritana
Sono presentati e discussi i risultati
preliminari relativi ad una ri-localizzazione
probabilistica non-lineare 3D dei terremoti
dell’area compresa tra il Tirreno meridionale
e l’Arco Calabro-Peloritano (Italia
meridionale).
Scopo del lavoro è dimostrare che
l’applicazione di un’approccio probabilistico
non-lineare nella localizzazione dei terremoti
può fornire dei risultati più accurati ai fini
della sorveglianza, ovviando al problema
degli outlier, rispetto alle tecniche di
localizzazione lineari (e.g. Hypoellipse), che
minimizzano simultaneamente tutti i residui
tra fasi osservate e calcolate.
Il programma utilizzato è NonLinLoc
[Lomax, et al., 2000; Lomax, et al., 2001;
Lomax, 2005; http://www.alomax.net/nlloc;
NonLinLoc di seguito] il quale permette di
effettuare un’efficiente ricerca globale dello
spazio dei parametri ipocentrali (coordinate
spaziali e tempo origine) ottenendo una
stima della funzione densità di probabilitÃ
(pdf, probability density function) a
posteriori. La pdf fornisce una descrizione
completa della localizzazione e delle sue
incertezze; il campionamento dello spazio
dei parametri ipocentrali è stato fatto
mediante la tecnica Oct-tree nella regione
compresa tra 37.75 e 39.40 N in latitudine e
tra 14.80 e 16.80 E in longitudine, e
utilizzando tutti gli eventi con profondità H
≤30 km.
La struttura dell’Oct-tree è stata imposta in
100,000 celle ed un insieme di queste celle
viene poi salvata in modo da poter
rappresentare graficamente la pdf mediante
nubi di punti a diversa densità .
Il dataset utilizzato per le nostre analisi è
composto da 1,304 terremoti, di 1.0<M<4.3,
registrati nel periodo compreso tra il 1994 e
il 2006; il modello di velocità 3D adottato è
stato ottenuto da Barberi et al., 2008 [poster
presentato a questo convegno] invertendo lo stesso dataset, mediante l’utilizzo del
software TomoDD.
I risultati ottenuti sono stati confrontati sia
con le localizzazioni 1D (Hypoellipse) che
con quelle 3D. Si evidenzia una maggiore
clusterizzazione degli eventi e, soprattutto,
un evidente miglioramento della qualità delle
localizzazioni utilizzando il modello di
velocità crostale 3D. Per cui riteniamo che,
l’applicazione del metodo probabilistico
associato ad un buon modello di velocità 3D,
può essere utilizzato ai fini di sorveglianza
Long-term effect of tillage, nitrogen fertilization and cover crops on soil organic carbon and total nitrogen content
No-tillage, N fertilization and cover crops are known to play an important role in conserving or increasing SOC and STN but the effects of their interactions are less known. In order to evaluate the single and combined effects of these techniques on SOC and STN content under Mediterranean climate, a long term experiment started in 1993 on a loam soil (Typic Xerofluvent) in Central Italy. The experimental variants are: conventional tillage (CT) and no-tillage (NT), four N fertilization rates (N0, N1, N2 and N3) and four soil cover crop (CC) types (C - no cover crop; NL - non-legume CC; LNL - low nitrogen supply legume CC, and HNL - high nitrogen supply legume CC).The nitrogen fertilization rates (N0, N1, N2 and N3) were: 0, 100, 200, 300kgNha-1 for maize (Zea mays, L.); 0, 60, 120,180kgNa-1 for durum wheat (Triticum durum Desf.); 0, 50, 100, 150kgNha-1 for sunflower (Helianthus annuus L.).From 1993 to 2008, under the NT system the SOC and STN content in the top 30cm soil depth increased by 0.61 and 0.04Mgha-1year-1 respectively. In the same period, the SOC and STN content under the CT system decreased by a rate of 0.06 and 0.04Mgha-1year-1 respectively. During the experimental period, N1, N2 and N3 increased the SOC content in the 0-30cm soil layer at a rate of 0.14, 0.45 and 0.49Mgha-1year-1. Only the higher N fertilization levels (N2 and N3) increased STN content, at a rate of 0.03 and 0.05Mgha-1year-1.NL, LNL and HNL cover crops increased SOC content by 0.17, 0.41 and 0.43MgCha-1year-1 and -0.01, +0.01 and +0.02MgNha-1year-1.Significant interactions among treatments were evident only in the case of the N fertilization by tillage system interaction on SOC and STN concentration in the 0-10. cm soil depth in 2008.The observed SOC and STN variations were correlated to C returned to the soil as crop residues, aboveground cover crop biomass and weeds (C input).We conclude that, under our Mediterranean climate, it is easier to conserve or increase SOC and STN by adopting NT than CT. To reach this objective, the CT system requires higher N fertilization rates and introduction of highly productive cover crops
Localizzazione probabilistica 3D (NonLinLoc) applicata all’area calabro-peloritana
Sono presentati e discussi i risultati
preliminari relativi ad una ri-localizzazione
probabilistica non-lineare 3D dei terremoti
dell’area compresa tra il Tirreno meridionale
e l’Arco Calabro-Peloritano (Italia
meridionale).
Scopo del lavoro è dimostrare che
l’applicazione di un’approccio probabilistico
non-lineare nella localizzazione dei terremoti
può fornire dei risultati più accurati ai fini
della sorveglianza, ovviando al problema
degli outlier, rispetto alle tecniche di
localizzazione lineari (e.g. Hypoellipse), che
minimizzano simultaneamente tutti i residui
tra fasi osservate e calcolate.
Il programma utilizzato è NonLinLoc
[Lomax, et al., 2000; Lomax, et al., 2001;
Lomax, 2005; http://www.alomax.net/nlloc;
NonLinLoc di seguito] il quale permette di
effettuare un’efficiente ricerca globale dello
spazio dei parametri ipocentrali (coordinate
spaziali e tempo origine) ottenendo una
stima della funzione densità di probabilitÃ
(pdf, probability density function) a
posteriori. La pdf fornisce una descrizione
completa della localizzazione e delle sue
incertezze; il campionamento dello spazio
dei parametri ipocentrali è stato fatto
mediante la tecnica Oct-tree nella regione
compresa tra 37.75 e 39.40 N in latitudine e
tra 14.80 e 16.80 E in longitudine, e
utilizzando tutti gli eventi con profondità H
≤30 km.
La struttura dell’Oct-tree è stata imposta in
100,000 celle ed un insieme di queste celle
viene poi salvata in modo da poter
rappresentare graficamente la pdf mediante
nubi di punti a diversa densità .
Il dataset utilizzato per le nostre analisi è
composto da 1,304 terremoti, di 1.0<M<4.3,
registrati nel periodo compreso tra il 1994 e
il 2006; il modello di velocità 3D adottato è
stato ottenuto da Barberi et al., 2008 [poster
presentato a questo convegno] invertendo lo stesso dataset, mediante l’utilizzo del
software TomoDD.
I risultati ottenuti sono stati confrontati sia
con le localizzazioni 1D (Hypoellipse) che
con quelle 3D. Si evidenzia una maggiore
clusterizzazione degli eventi e, soprattutto,
un evidente miglioramento della qualità delle
localizzazioni utilizzando il modello di
velocità crostale 3D. Per cui riteniamo che,
l’applicazione del metodo probabilistico
associato ad un buon modello di velocità 3D,
può essere utilizzato ai fini di sorveglianza
Seismic location improvements from an OBS/H temporary network in Southern Tyrrhenian Sea
We present the first investigation performed on the seismicity of Southern Tyrrhenian Sea, off-shore Sicily
with the contribution of data from broad-band ocean bottom seismometers and hydrophones (OBS/H). Offshore
data were recorded during the TYrrhenian Deep sea Experiment (TYDE) from December 2000 to May
2001 in the Southern Tyrrhenian Sea. Hypocenter locations of a cluster of 53 seismic events occurred in
March 2001 in north-eastern Sicily were estimated by the integration of land (permanent network) and offshore
(temporary network) data and compared with locations estimated from land data only. The scatter of
the cluster was evaluated by dispersion parameters. The off-shore data significantly reduced the scatter of
the swarm hypocenters also restricting the depth range of the cluster. Moreover, space trends of the event
distribution originally shown by the land data were only partially confirmed by the land-sea joint data.
In order to assess the efficiency in terms of hypocenter mislocations in the subject area, of a land-sea
integrated network with respect to a land-based network, we performed simulations by assuming a grid
distribution of earthquakes and a recent local 3D velocity model, computing synthetic arrival times of body
waves to the stations of both network configurations (integrated and land-based) perturbing the computed
times and relocating earthquakes by inversion. The results of the synthetic tests demonstrated that the
presence of sea bottom stations in the Tyrrhenian basin can reduce the mislocations of large magnitude
and/or superficial earthquakes in the southernmost Calabria and Messina Strait and of low magnitude and/or
deep earthquakes in north-eastern Sicily. The major accuracy of synthetic earthquake locations obtained
including OBS/H data provides an additional support to the interpretation of the cluster occurred in March
2001 and to the opportunity of long-term installation of an off-shore network like TYDE in the study region
Health Hazard from Gas Emissions in the Quaternary Volcanic Province of Latium (Italy)
The Quaternary Volcanic Province of Central Italy is characterized by zones with a huge endogenous degassing where frequent, sometimes lethal, accidents occur to people and animals. The emitted gas has a deep origin (volcanic or mantle) and is mainly composed by CO2 (up to 98%) and H2S (1-4%), which may reach dangerous concentrations both in open air and indoor. Here we present the results of a multiparametric geochemical study carried out in 2007-2009 in the Provinces of Rome and Viterbo (Latium), with the aim of assessing the health hazard of their main gas emission sites (GES). Three types of GES were investigated: 1. natural, open-air thermal pools, 2. within natural reserves, 3. near to inhabited zones. More than 15 GES have been studied, and here we will illustrate some of the cases with the highest hazard. Results are presented for the sites of Vejano and Mola di Oriolo (Viterbo), Caldara di Manziana, Tor Caldara and Solforata di Pomezia (Rome). Cava dei Selci is a well-known inhabited area of the volcanic complex of Colli Albani (Rome). In each site, multi-technique surveys have been carried out to estimate the total gas output and its concentration in air, by measuring: CO2 and H2S viscous and diffuse flux (the latter by accumulation chamber), CO2 and H2S concentration in air (by TDL profiles and punctual Draeger measurements); moreover, the chemical and isotopic composition of the gas was determined in each site. In all these zones, lethal air concentrations may be reached by both H2S and CO2, but more frequently by the first. Recommendations for risk reduction were given to Civil Protection authorities.Comission of Cities and Volcanoes (CaV) of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) Agencia Española de Cooperación Internacional para el Desarrollo (AECID), Gobierno de España Ministerio de Ciencia e Innovación (MICINN), Gobierno de España
Unidad Militar de Emergencias (UME), Ministerio de Defensa, Gobierno de España
Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI), Gobierno de Canarias ViceconsejerÃa de Infraestructuras y Planificación, Gobierno de Canarias ConsejerÃa de Turismo, Gobierno de Canarias ConsejerÃa de Medio Ambiente y Ordenación Territorial, Gobierno de Canarias
ViceconsejerÃa de Cultura y Deportes, Gobierno de Canarias Instituto Español de OceanografÃa (IEO)Instituto Geológico y Minero de España (IGME)Instituto Geográfico Nacional (IGN)Academia Canaria de Seguridad
Federación Canaria de Municipios (FECAM)
Universidad de La Laguna (ULL)Instituto de Estudios Hispánicos de Canarias (IEHC)
CajaCanariasPublishedPuerto de la Cruz, Tenerife, Spain1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive4.5. Studi sul degassamento naturale e sui gas petroliferiope
Hazardous gas emissions from the flanks of the quiescent Colli Albani volcano (Rome, Italy)
Gas hazard was evaluated in the three most important cold gas emission zones on the flanks of the quiescent Colli Albani volcano. These zones are located above structural highs of the buried carbonate basement which represents the main regional aquifer and the main reservoir for gas rising from depth. All extensional faults affecting the limestone reservoir represent leaking pathways along which gas rises to the surface and locally accumulates in shallow permeable horizons forming pressurized pockets that may produce gas blowout when reached by wells. The gas, mainly composed by CO2 (>90 vol.%), contains appreciable quantities of H2S (0.35-6 vol.%), and both represent a potentially high local hazard. Both gases are denser than air and accumulate near ground where they may reach hazardous concentrations, and actually lethal accidents frequently occur to animals watering at local ponds. In order to evaluate the rate of degassing and the related hazard, CO2 and H2S diffuse soil flux surveys have been repeatedly carried out by accumulation chamber. The viscous gas flux of some important discrete emissions has been also evaluated and the CO2 and H2S air concentration measured by portable devises and by Tunable Diode Laser profiles. The minimum potential lethal concentration of the two gases (250 ppm for H2S and 8 vol.% for CO2) is 320 times higher for CO2, whereas the CO2/H2S concentration ratio in the emitted natural gas is significantly lower (15-159). This explains why H2S reaches hazardous, even lethal, concentrations more frequently than CO2. A relevant hazard exists for both gases in the depressed zones (channels, excavations) particularly in the non-windy early hours of the day
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