250 research outputs found
Detection of Volcanic Plumes by GPS: the 23 November 2013 Episode on Mt. Etna
The detection of volcanic plumes produced during explosive eruptions is important to improve our under-
standing on dispersal processes and reduce risks to aviation operations. The ability of Global Position-ing
System (GPS) to retrieve volcanic plumes is one of the new challenges of the last years in volcanic plume de -
tection. In this work, we analyze the Signal to Noise Ratio (SNR) data from 21 permanent stations of the GPS
network of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, that are located on the Mt.
Etna (Italy) flanks. Being one of the most explosive events since 2011, the eruption of November 23, 2013 was
chosen as a test-case. Results show some variations in the SNR data that can be correlated with the presence of
an ash-laden plume in the atmosphere. Benefits and limitations of the method are highlighted
Evidences of a contractional pattern along the northern rim of the Hyblean Plateau (Sicily, Italy) from GPS data
In this paper we present the main results inferred from GPS data collected between 1998.00 and 2009.78 along the northern rim of the Hyblean Plateau from 9 continuous and 23 survey-mode sites. From a geological point of view, this area is of great interest because 1) it represents an important piece of the collision front between Nubia and Eurasia 2) it is very close to the biggest European volcano Mount Etna and 3) it has been hit by strong earthquakes in the past (1169 and 1693) that struggled the cities of Catania, Siracusa and Ragusa provoking tens of thousands of casualties. We have found that the ground deformation pattern clearly defines an area of prevailing contraction along the northern rim of the Hyblean Plateau with a maximum negative strain-rate of about 0.14Âľstrain/yr in agreement with both geological and Interferometric Synthetic Aperture Radar (InSAR) data. In addition, a transition to extensional regime is acting toward the central sector of the plateau. The velocity field referred to the Eurasian frame indicates that a large part of the plateau is dominated by a 5.4mm/yr northward motion
A Dynamic Bayesian Network for Mt. Etna Volcano State Assessment
Nowadays, the real-time monitoring of Mt. Etna volcano is mostly delegated to one or more human experts in
volcanology, who interpret the data coming from different kind of monitoring networks. Among their duties, the
evaluation of the volcano state is one of the most critical task for civil protection purposes. Unfortunately, the
coupling of highly non-linear and complex volcanic dynamic processes leads to measurable effects that can show a
large variety of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded
data the volcano state needs to be expressed in probabilistic terms, thus making the fast volcano state assessment
sometimes impracticable for the personnel on duty at the 24h control room. With the aim of aiding the personnel
on duty in volcano monitoring, here we present an expert system approach based on Bayesian networks to estimate
automatically the ongoing volcano state from all the available different kind of measurements. A Bayesian network
is a static probabilistic graphical model that represents a set of random variables and their conditional dependencies
via a directed acyclic graph. We consider model variables both the measurements and the possible states of the
volcano. In order to include the time in the model, we use a Dynamic Bayesian Network (DBN) which relates
variables to each other over adjacent time steps. The model output consists of an estimation of the probability
distribution of the feasible volcano states. We build the model by considering the long record of data from 2011 to
2014 and we cross-validate it by considering 3 years for parameter estimation and 1 year for testing in simulated real-time mode
Assessing seismic efficiency from scalar Moment-rates: an application to Mt. Etna volcano (Italy)
Here we propose an improved estimation of the scalar seismic (from instrumental and historical catalogues), geodetic and geologic moment-rates for the eastern flank of Mt. Etna. The estimated moment-rates have been compared in terms of seismic efficiency. Results show that all the calculated efficiency values are lower than 40%, i.e., the geodetic moment-rate estimations are generally larger than the seismic and the geologic ones. Although a number of reasons may account for the observed discrepancy, we are confident that a large amount of the deformation affecting the eastern flank occurs aseismically
are the source models of the m 7 1 1908 messina straits earthquake reliable insights from a novel inversion and a sensitivity analysis of levelling data
n/
Deliveries by caesarean sections on request of women: legal-medical evidence
Introduction: In Italy the use of caesarean delivery has a rising trend moving away from European standards appeared on
Euro-Peristat on maternal and child health, presenting the highest percentage of use of this procedure with significant
regional differences. This study have analyzed the most recent data of a Sicilian reality about normal delivery and
caesarean sections carried out in a hospital situated in Messina (Italy).
Materials and methods: A total number of 1,573 medical records from 1st January 2011 to 31st December 2013 were
analyzed and data gathered were statistically examined to describe general and specific parameters of the sample making
use of Epi Info 7.1.4 software (CDC Atlanta â USA). Chi-square test was used to show any statistic differences among
studied population.
Results: Overall data showed that were carried out 38.27% of spontaneous deliveries, 7.06% of induced labor, and 54.67%
of caesarean deliveries. There were no significant statistical differences between recourse to caesarean section and vaginal
delivery in relation to nationality, age, level of education and/or work. The enrolled group, based on the parameters
examined, was divided into appropriate caesarean section, in 79.49% of cases, inappropriate in 7.20% (motherâs request)
and unjustified in 13.31% (with no indication, incomplete medical record). An examination of the anesthetic medical
records showed that the caesarean section was considered to be urgent in 31.74% of the cases; however in 17.92% of these
cases there is no information in the medical records justifying the use of emergency procedures.
Conclusion: The reported data from the study that we conducted, lead to medical-legal and juridical considerations,
especially as regards the use of caesarean delivery on the woman request. The complexity of the phenomenon requires the
development of a variety of intervention strategies, not only for issues related to the reduction of health care costs, but also
with regard to the clinical risk management and medical legal aspects related to the several profiles of professional responsibility
Etn@ref: a geodetic reference frame for Mt. Etna GPS networks
In volcanology, one of the most important instruments for scientific community interested in modelling the physical processes related to magma movements in the shallow crust is geodetic data. Since the end of the 1980s, GPS surveys and Continuous GPS stations (CGPS) have greatly improved the possibility to measure such movements with high time and space resolution. However, physical modelling requires that any external influence on the data, not directly related to the investigated quantity, must be filtered. One major tricky factor in determining a deformation field using GPS displacement vectors and velocities is the correct choice of a stable reference frame. In this work, using more than a decade of GPS measurements, we defined a local reference frame in order to refer the Mt. Etna ground deformation pattern to a rigid block. In particular, we estimated the Euler pole for the rigid block by minimizing, with a weighted least squares inversion, the adjustments to two horizontal components of GPS velocity at 13 âfiducialâ sites located within 350 km around Mt. Etna. The inversion inferred an Euler pole located at 38.450° N and -107.702° E and a rotation rate of 0.263 deg/Myr
A preliminary census of engineering activities located in Sicily (Southern Italy) which may âpotentiallyâ induce seismicity
The seismic events caused by human engineering activities are commonly termed as âtriggeredâ and âinducedâ.
This class of earthquakes, though characterized by low-to-moderate magnitude, have signiďŹcant social and eco-
nomical implications since they occur close to the engineering activity responsible for triggering/inducing them
and can be felt by the inhabitants living nearby, and may even produce damage. One of the ďŹrst well-documented
examples of induced seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake
occurred close to the Oued Fodda Dam. By the continuous global improvement of seismic monitoring networks,
numerous other examples of human-induced earthquakes have been identiďŹed. Induced earthquakes occur at
shallow depths and are related to a number of human activities, such as ďŹuid injection under high pressure
(e.g. waste-water disposal in deep wells, hydrofracturing activities in enhanced geothermal systems and oil
recovery, shale-gas fracking, natural and CO2 gas storage), hydrocarbon exploitation, groundwater extraction,
deep underground mining, large water impoundments and underground nuclear tests. In Italy, induced/triggered
seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Despite this suspected case
and the presence in the Italian territory of a large amount of engineering activities âcapableâ of inducing seismicity,
no extensive researches on this topic have been conducted to date. Hence, in order to improve knowledge and
correctly assess the potential hazard at a speciďŹc location in the future, here we started a preliminary study on the
entire range of engineering activities currently located in Sicily (Southern Italy) which may âpotentiallyâ induce
seismicity. To this end, we performed:
⢠a preliminary census of all engineering activities located in the study area by collecting all the useful information
coming from available on-line catalogues;
⢠a detailed compilation of instrumental and historical seismicity, focal mechanisms solutions, multidisciplinary
stress indicators, GPS-based ground deformation ďŹeld, mapped faults, etc by merging data from on-line catalogues
with those reported in literature.
Finally, for each individual site, we analysed: i) long-term statistic behaviour of instrumental seismicity (mag-
nitude of completeness, seismic release above a threshold magnitude, depth distribution, focal plane solutions);
ii) long-term statistic behaviour of historical seismicity (maximum magnitude estimation, recurrence time inter-
val, etc); iii) properties and orientation of faults (length, estimated geological slip, kinematics, etc); iv) regional
stress (from borehole, seismological and geological observations) and strain (from GPS-based observations) ďŹelds.UnpublishedVienna (Austria)6T. SismicitĂ indotta e caratterizzazione sismica dei sistemi naturaliope
A comprehensive interpretative model of slow slip events on Mt. Etnaâs eastern flank
Starting off from a review of previous literature on kinematic models of the unstable eastern
flank of Mt. Etna, we propose a new model. The model is based on our analysis of a large quantity of multidisciplinary
data deriving from an extensive and diverse network of INGV monitoring devices deployed
along the slopes of the volcano. Our analysis had a twofold objective: first, investigating the origin of the
recently observed slow-slip events on the eastern flank of Mt. Etna; and second, defining a general kinematic
model for the instability of this area of the volcano. To this end, we investigated the 2008â2013
period using data collected from different geochemical, geodetic, and seismic networks, integrated with
the tectonic and geologic features of the volcano and including the volcanic activity during the observation
period. The complex correlations between the large quantities of multidisciplinary data have given us the
opportunity to infer, as outlined in this work, that the fluids of volcanic origin and their interrelationship
with aquifers, tectonic and morphological features play a dominant role in the large scale instability of the
eastern flank of Mt. Etna. Furthermore, we suggest that changes in the strain distribution due to volcanic
inflation/deflation cycles are closely connected to changes in shallow depth fluid circulation. Finally, we propose
a general framework for both the short and long term modeling of the large flank displacements
observed.Published635â6581IT. Reti di monitoraggio e OsservazioniJCR Journalrestricte
Peptide receptor radionuclide therapy for aggressive pituitary tumors: a monocentric experience
In aggressive pituitary tumors (PT) showing local invasion or growth/recurrence despite multimodal conventional treatment, temozolomide (TMZ) is considered a further therapeutic
option, while little data are available on peptide receptor radionuclide therapy (PRRT). We analyzed PRRT effectiveness, safety and long-term outcome in three patients with aggressive
PT, also reviewing the current literature. Patient #1 (F, giant prolactinoma) received five cycles (total dose 37 GBq) of 111In-DTPA-octreotide over 23 months, after unsuccessful surgery and
long-term dopamine-agonist treatment. Patient #2 (M, giant prolactinoma) underwent two cycles (12.6 GBq) of 177Lu-DOTATOC after multiple surgeries, radiosurgery and TMZ. In patient #3 (F, non-functioning PT), five cycles (29.8 GBq) of 177Lu-DOTATOC followed five surgeries, radiotherapy
and TMZ. Eleven more cases of PRRT-treated aggressive PT emerged from literature. Patient #1 showed tumor shrinkage and visual/neurological amelioration over 8-year follow-up, while the
other PTs continued to grow causing blindness and neuro-cognitive disorders (patient #2) or monolateral amaurosis (patient #3). No adverse effects were reported. Including the patients
from literature, 4/13 presented tumor shrinkage and clinical/biochemical improvement after PRRT. Response did not correlate with patientsâ gender or age, neither with used radionuclide/peptide, but PRRT failure was significantly associated with previous TMZ treatment. Overall, adverse effects occurred only in two patients. PRRT was successful in 1/3 of patients with
aggressive PT, and in 4/5 of those not previously treated with TMZ, representing a safe option after unsuccessful multimodal treatment. However, at present, considering the few data, PRRT
should be considered only in an experimental setting
- âŚ