380 research outputs found
L’evoluzione tettonica del continente antartico
Because of its location, Antarctica represents an observation point of special interest to global seismology. Also, seismology can greatly contribute to the knowledge of Antarctic neotectonics through the study of continental seismicity and lithospheric structure. The sporadic distribution of seismographic stations south of latitude -45 both restricts our knowledge of the Antarctic continent, and leads to a bias in the interpretation of global geophysical properties of the Earth. Installation of seismographic stations should therefore be a priority for an Antarctic program having access to infrastructure in the area and there are particular activities carried on in the framework of the Italian Antarctic program (Programma Nazionale di Ricerche in Antartide, PNRA). In fact, the previously held notion that Antarctica is essentially aseismic has been disproved by using records from established Global Seismic Network stations and recently deployed temporary stations on the Antarctic continent. However, the seismicity observed in Antarctica is very low in comparison with other continental intraplate regions. In the continental intraplate region of Antarctica, earthquakes occur in three settings. Two are likely to have distributions with a tectonic control (although the level may be suppressed by ice-cover); those in the Transantarctic Mountains and scattered events in the interior. Finally, seismicity in the coastal zone and continental margin is likely to be most strongly controlled by the interaction between glacial isostatic adjustment and lithospheric thickness, with a regional tectonic component in some locations
Il Museo Geofisico di Rocca di Papa: tra divulgazione e ricerca scientifica
The Geophysical Museum of Rocca di Papa is located in an historical, three floor building, of the small
town Rocca di Papa, twentyfive kilometres from Rome. The edifice was, until 1931, the place of the
Geodynamic Observatory, created in 1889 by the famous seismologist Michele Stefano De Rossi. The
museum is due to an agreement between the Town Council of Rocca di Papa and the Istituto Nazionale di
Geofisica (INGV, one of the most important European Research Institutions operating in geophysics) signed
in 2000. After bureaucratic passages and two years of important restoration the museum was open to the
public at 26th February 2005.
The main aim of the Geophysical Museum is to illustrate how experimental data and information,
accumulated by science in the course of time, led to new hypotheses on the internal structure of the Earth.
The target of the educational and of the scientific disciplines of the Museum is mainly school students of all
ages, but also local residents, and tourists: since its opening, approximately two years ago, the Museum has
been visited by more than eight-thousand people. Posters, movie presentations, plastics, games and interactive
experiments explain to visitors the main topics of geophysics and the stages of scientific research which led to
the modern concept of the Earth internal model. Seismic instruments and games are easily accessible so that
the visitor can interact with them: experimental data are recorded in real time and displayed through different
monitors placed throughout the rooms. The museum has also a small cinema for three dimensional projections
which allow visitors to experience a virtual tour on the Alban Hills, the seismic zone where the museum is
located, and also on some other Italian tectonic belts where earthquakes occurred in past. The article
introduces the museum and the seismological characteristics of the area, and describes the activities, the
exhibits of the Museum and their methodology
LA RETE SISMICA DELLA PIANA DI GUIDONIA (LAZIO): DATI PRELIMINARI
After the seismic period during 2001-2002 that has interested the Plain of Guidonia, situated
about fifteen kilometres NE of Rome, which events greatest resentment reached the V-VI MCS, have
been installed a local seismic purchased by Comune of Guidonia-Montecelio (Rm). The seismic
network (RLG) consists of three digital seismic stations with distances of each other about 2
kilometers, activated to leave from the June 2004 and equipped with three components 1 Hz
sismometer. Subsequently, the RLG has enriched of other four digital stations equipped with three
components 5 Hz sismometer This network has like main objective the high quality data that agree a
better definition of the seismic local activity. These data, that integrate those of the Seismographic
Centralized National Network (SCNN), agreed a better ipocentre location. Network geometriy was
chosen so as to give back the RLG an independent structure to carry out reliable seismicity locations
that characterizes the plain of Guidonia. Unfortunately, industrial and human activity, increases in
considerable manner the seismic noise, giving back difficult the record of small events. For this motive
the location of the sites was more times changed, and lately, after a seismic crisis in the northern side
of the Mountains Cornicolani, that has presented with the same features of that of 2001 of Guidonia,
some stations were moved in the neighboring village of Palombara Sabina (Rm)
Recent seismicity of the «Acque Albule» travertine basin
The seismic period which occurred in a portion of Guidonia Montecelio and Tivoli territory, two towns situated about twenty kilometres NE of Rome, affected four areas with a high density of population: Guidonia, Collefiorito, Villalba and Bagni di Tivoli. Even though the events had a very low magnitude (less than 3.0), local phenomena, like rumbles and strong vibrations of the ground, frightened inhabitants also because some months before (January 26, 2001) in a village named Marcellina situated a few kilometres away from Guidonia, a large sinkhole (600 m) had appeared without fore signals. The «Istituto Nazionale di Geofisica e Vulcanologia» (INGV) installed some digital stations that monitored the seismic phenomena. This paper has the aim to process all the information acquired during the period, both from the micro and macro seismic point of view, in order to explain the phenomenology that involved the area. The synergy of the two methodologies lead us to the conclusion that two different seismotectonic structures originated the events, one in an anti-apenninic direction, the other in a N-S direction
RECENT SEISMICITY (2000-2007) IN THE TIBURTINI-PRENESTINI MOUNTAINS REGION (LATIUM, ITALY)
A detailed knowledge of the seismicity distribution enables us to gain a better understanding of the recent tectonic evolution and
the present-day state of stress of the Tiburtini and Prenestini Mountains region, whose seismic importance is related with the
nearness to the town of Rome. It has been carried out an analysis of the seismicity of the region using the data recorded by the
permanent stations belonging to the Italian National Seismic Network (RSNC) from 2000, and subsequently integrated with data
of local seismic network from 2003 to 2007. The increase of the number of stations in the last years allow us to obtain better
quality earthquake localization as before done. We have produced a large database of re-picked events collecting arrival times of
P and S waves of local earthquakes with magnitude larger than 2.0, belonging to the 2000-2007 period.
The work is subdivided into three step. The first one consists in the determination of the VP/VS ratio using the modified Wadati
method. In the second step we perform the analysis of the 1D velocity model that better approximates the structure of the crust
in the studied area using the VELEST code (Kissling et al., 1995). Finally, we have the step with earthquake locations and focal
mechanisms computation using the first motion polarities method. Fault plane solutions are selected following the two quality
factors defined by the FPFIT code (Reasenberg and Oppenheimer, 1985). For the determination of the regional stress field it is
used the focal mechanism inversion method elaborated by Gephart and Forsyth (1984). These results are compared with those
available from the historical seismicity that struck the region under study
A cost-effectiveness analysis of caspofungin vs. liposomal amphotericin B for treatment of suspected fungal infections in the UK
Objective: To evaluate the cost-effectiveness of caspofungin vs. liposomal amphotericin B in the treatment of suspected fungal infections in the UK.Methods: The cost-effectiveness of caspofungin vs. liposomal amphotericin B was evaluated using a decision-tree model. The decision tree was populated using both data and clinical definitions from published clinical studies. Model outcomes included success in terms of resolution of fever, baseline infection, absence of breakthrough infection, survival and quality adjusted life years (QALYs) saved. Discontinuation due to nephrotoxicity or other adverse events were included in the model. Efficacy and safety data were based on additional analyses of a randomised, double blind, multinational trial of caspofungin compared with liposomal amphotericin B. Information on life expectancy, quality of life, medical resource consumption and costs were obtained from peer-reviewed published data.Results: The caspofungin mean total treatment cost was £9762 (95% uncertainty interval 6955–12 577), which was £2033 (−2489; 6779) less than liposomal amphotericin B. Treatment with caspofungin resulted in 0.40 (−0.12; 0.94) additional QALYs saved in comparison with liposomal amphotericin B. Probabilistic sensitivity analysis found a 95% probability of the incremental cost per QALY saved being within the generally accepted threshold for cost-effectiveness (£30 000). Additional analyses with varying dose of caspofungin and liposomal amphotericin B confirmed these findings.Conclusion: Given the underlying assumptions, caspofungin is cost-effective compared with liposomal amphotericin B in the treatment of suspected fungal infections in the UK.<br/
Seismicity and seismogenic structures of Central Apennines (Italy): constraints on the present-day stress field from focal mechanisms – The SLAM (Seismicity of Lazio-Abruzzo and Molise) project
The aim of the SLAM (Seismicity of Lazio, Abruzzo and Molise region) project is to provide new insight on the seismotectonic and seismogenesis of a wide portion of central Italy situated between areas affected by
recent destructive events such as the 2009, Mw = 6.3, L’Aquila earthquake to the north and the 2002, Mw = 5.8, Molise earthquake to the east. We present new results for the microseismic activity in the Central
Apennines, occurred in the period 2009 – 2013, by analyzing seismogram recordings from two temporary networks of up to 17 stations in combination with data from three networks of permanent stations
The monitoring of seismic activity at Nyiragongo volcano through telemetered seismic network Goma Volcano Observatory (Democratic Republic of the Congo)
The eruption, in January 2002, of Mount Nyiragongo in eastern Congo, and the humanitarian disaster that followed in its wake, underlined the critical importance of accurate seismology to predict when such events will take place. Thus, a seismic telemeterd network, with centre in Goma Observatory, was built across Virunga area to help the moniotring of Volcano.
Mount Nyiragongo is a volcano in the Virunga Mountains associated with the Great Rift Valley. The most prominent feature of the Democratic Republic of Congo's geology is the Western Rift Zone (WRZ), which runs through its eastern border regions and neighbouring countries (e.g. Uganda, Rwanda, Burundi, Tanzania) between 28°E to 32°E and 4°N to 12°S. The WRZ extends over a 1600 km arc, including lakes Albert, Eduard, Kivu and Tanganyika, until it joins the eastern branch. The Western Rift Valley of Africa has experienced severe earthquakes and volcanic eruptions in recent historical times. Earthquakes with magnitude >=6 are not frequent, but may cause significant destruction. They occur mostly in DRC and neighbouring countries (e.g. Uganda and Tanzania). In 1991, IAVCEI selected the Nyiragongo volcano as the ‘African decade volcano’ for the International Decade of Natural Disaster Reduction (IDNDR) program. Nyiragongo is located about 20 km north of Lake Kivu and 15 km north of Goma, a city of about 500,000 inhabitants. Goma is twinned to Gisenyi in Rwanda, which has a population of about 100,000. Several small villages are also located on the flank of the volcano. Population growth and poor or non-existent planning has led to relatively uncontrolled use of land for building, and the development of sites vulnerable to earthquake and/or volcanic risk.EUROPEAN CENTER FOR GEODYNAMICS AND SEISMOLOGY
Royal Museum for Central Africa, B
National Museum of Nat. History, LUnpublishedLuxembourg1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope
Environmental pre-exploitation monitoring of Torre Alfina geothermal system (Central Italy)
An interesting project of geothermal pilot plant, with no-gas emission in atmosphere, has been submitted for approval in the medium-enthalpy geothermal field of Torre Alfina. This prompted us to develop a geochemical and geophysical monitoring of the area with the aim of establishing a background information to reco-gnize anomalous gas emission, induced seismicity and subsidence, possibly related to the field exploitation. The exploration conducted by Enel in the years ‘70 - '80, including the drilling of 9 deep wells, has shown the existence of a medium-enthalpy geothermal field in the Torre Alfina zone, in central Italy. The area has been affected by a very complex geological evolution during the Neogene. It was affected by the Quaternary volcanism of the Tyrrhenian margin which, reached its climax between 0.6 and 0.3 Ma. The present stress field around Quaternary volcanoes of central Italy has a NE to ENE direction of extension, in agreement with the alignment of Quaternary volcanoes and earthquake fault plane solutions, with T axes preferentially oriented between NE and ENE.PublishedPrague, Czech Republic, June 22 to July 2, 20156T. Sismicità indotta e caratterizzazione sismica dei sistemi naturaliope
Preliminary results from seismic monitoring at Nyiragongo Volcano (Democratic Republic Of Congo) through telemetered seismic network, Goma Volcano Observatory
Following the January 17, 2002 catastrophic eruption of the Nyiragongo Volcano (Democratic Republic of Congo) located in the western branch of the East African Rift, a great effort has been devoted to the seismic surveillance of this volcanic area. The 2002 eruption destroyed one/tenth of the city of Goma, leaving more than 100,000 homeless. In order to correctly monitor the seismic activity at Nyiragongo volcano for both scientific and civil defence purposes, the Istituto Nazionale di Geofisica e Vulcanologia in cooperation with GVO (Goma Volcanological Observatory), between November 2003 and May 2004 installed a new telemetered seismic network consisting of seven digital stations. The network is operational and seismic signals are continuously recorded at the GVO. In this study, we focus mainly on two aspects: (1) the deployment, in the field, of this new digital seismic network and the related real-time data acquisition system, and (2) the first results from a preliminary data analysis based on 6-month seismic recordings. Based on the waveforms and spectral analysis, long-period and very long period events (both, tectonic and volcanic-tectonic earthquakes), have been detected. Furthermore, we succeeded in locating more than 100 earthquakes. These results should strongly encourage the use of such a network data for seismotectonic studies of the area.Published117-1271.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveN/A or not JCRreserve
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