ALBERT

Beschreibung: No abstract available

Beschreibung: The present report describes a desktop computer-based method for the quantitative assessment of the area occupied by immunoreactive terminals in close apposition to nerve cells in relation to the perimeter of the cell soma. This method is based on Fast Fourier Transform (FFT) routines incorporated in NIH-Image public domain software. Pyramidal cells of layer V of the somatosensory cortex outlined by GABA immunolabeled terminals were chosen for our analysis. A Leitz Diaplan light microscope was employed for the visualization of the sections. A Sierra Scientific Model 4030 CCD camera was used to capture the images into a Macintosh Centris 650 computer. After preprocessing, filtering was performed on the power spectrum in the frequency domain produced by the FFT operation. An inverse FFT with filter procedure was employed to restore the images to the spatial domain. Pasting of the original image to the transformed one using a Boolean logic operation called 'AND'ing produced an image with the terminals enhanced. This procedure allowed the creation of a binary image using a well-defined threshold of 128. Thus, the terminal area appears in black against a white background. This methodology provides an objective means of measurement of area by counting the total number of pixels occupied by immunoreactive terminals in light microscopic sections in which the difficulties of labeling intensity, size, shape and numerical density of terminals are avoided.

Beschreibung: An episode of nonsustained ventricular tachycardia was recorded from a crew member during the second month aboard the MIR space station. Although asymptomatic, this cardiac event increases the concern that serious cardiac dysrhythmias may be a limiting factor during long-duration spaceflight.

Beschreibung: We have analyzed a focal mechanism data set for Mount Vesuvius, consisting of 197 focal mechanisms of events recorded from 1999 to 2012. Using different approaches and a comparison between observations and numerical models, we have determined the spatial variations in the stress field beneath the volcano. The main results highlight the presence of two seismogenic volumes characterized by markedly different stress patterns. The two volumes are separated by a layer where the seismic strain release shows a significant decrease. Previous studies postulated the existence, at about the same depth, of a ductile layer allowing the spreading of the Mount Vesuvius edifice. We interpreted the difference in the stress pattern within the two volumes as the effect of a mechanical decoupling caused by the aforementioned ductile layer. The stress pattern in the top volume is dominated by a reverse faulting style, which agrees with the hypothesis of a seismicity driven by the spreading process. This agrees also with the persistent character of the seismicity located within this volume. Conversely, the stress field determined for the deep volume is consistent with a background regional field locally perturbed by the effects of the topography and of heterogeneities in the volcanic structure. Since the seismicity of the deep volume shows an intermittent behavior and has shown to be linked to geochemical variations in the fumaroles of the volcano, we hypothesize that it results from the effect of fluid injection episodes, possibly of magmatic origin, perturbing the pore pressure within the hydrothermal system.

Beschreibung: Published

Beschreibung: 1181–1199

Beschreibung: 4T. Fisica dei terremoti e scenari cosismici

Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi

Beschreibung: 5V. Sorveglianza vulcanica ed emergenze

Beschreibung: JCR Journal

Beschreibung: restricted

Beschreibung: Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity they may have important environmental impacts from the local to the global scale and they can severely affect the atmospheric and terrestrial environment also at timescales ranging from a few to million years. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. The aim of this study was to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Nine samples were collected by using the filtration technique at different sites on summer 2010 and 2011. Chemical and mineralogical analyses allowed to discriminate two main constituents: the first is mainly referable to the silicate component in the volcanic plume, like lithic and juvenile fragments, crystals (e.g., plagioclases, pyroxenes, oxides) and shards of volcanic glass; the second one is linked to the soluble components like sulfosalts or halide minerals (sulfates, chlorides and fluorides). These investigations are especially important in the study area because the summit of Mt. Etna is yearly visited by nearly one hundred thousand tourists that are exposed to potentially harmful compounds.

Beschreibung: Published

Beschreibung: Castellaneta Marina (TA), Italy

Beschreibung: 4V. Vulcani e ambiente

Beschreibung: open

Beschreibung: Explosive eruptions and volcanic passive degassing inject large quantities of gas and particles into the atmosphere that are ultimately deposited at the Earth’s surface through wet or dry deposition processes, affecting the atmosphere, the hydrosphere and the biosphere. Mount Etna (Italy) is one of the most prodigious and persistent sources of gases and particles to the troposphere. Volcanic emissions were studied at Etna volcano by using moss-bags technique. Mosses (Sphagnum species) were exposed around the volcano at different distances from the active vents to evaluate the impact of its emissions into the atmosphere and in the local surrounding. The results confirmed the huge amount of silicates, sulfates and halides compounds emitted into the atmosphere from Mount Etna. X-ray microanalysis showed that chemical composition of the particles is mostly defined by silicate (from pure silica to metal-rich silicate composition) and sulfate/halide compounds. The contents of major and trace elements in the Sphagnum moss-bags significantly increased after their exposure to volcanic emissions, confirming mosses as efficient accumulators. Metals uptake rate rapidly decreases with the distance from the volcanic emission vents. The elements that showed the greatest accumulation after exposition were S, Na, Fe, Al, Cu, V, As, Cd, Li, Se, Sc, Th, Bi and Tl. This study confirmed the marked environmental impact of volcanic emissions in the eastern sector of Etna, leading to an intense “geochemical anomaly” of volatile major and trace elements due to the fumigation by the volcanic plume, in agreement with passive biomonitoring studies reported by previous authors. Finally, moss-bags techniques provide a cheap and efficient method to investigate quantitatively in space and time the environmental impact of volcanogenic atmospheric deposition.

Beschreibung: Published

Beschreibung: Castellaneta Marina (TA), Italy

Beschreibung: 4V. Vulcani e ambiente

Beschreibung: open

Beschreibung: Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Etna (Italy) and Nyiragongo (D.R. Congo) are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake by the surrounding vegetation, with the aim to compare and identify differences and similarities between these two volcanoes. Volcanic emissions were sampled by using active filter-packs for acid gases (sulfur and halogens) and specific teflon filters for particulates (major and trace elements). The environmental impact of the volcanogenic deposition in the area surrounding of the crater rims was investigated by using different sampling techniques: bulk rain collectors’ gauges were used to collect atmospheric bulk deposition, and biomonitoring was carried out to collect gases and particulates by using endemic plant species. The estimates of the trace element fluxes confirm that Etna and Nyiragongo are large sources of metals into the atmosphere, especially considering their persistent state of passive degassing. The large amount of emitted trace elements is clearly reflected on the chemical composition of rainwater collected at the summit areas both for Etna and Nyiragongo. Moreover, the biomonitoring results highlight that bioaccumulation of trace elements is extremely high in the proximity of the crater rim and decreases with the distance from the active craters.

Beschreibung: Published

Beschreibung: 1 - 6

Beschreibung: 4V. Vulcani e ambiente

Beschreibung: JCR Journal

Beschreibung: open

Beschreibung: INGV, sezione di Napoli

Beschreibung: Published

Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi

Beschreibung: restricted

Beschreibung: Campi Flegrei caldera (Southern Italy) is among the areas with the highest volcanic risk in the world. The megacity of Naples, hosting more than 1 million inhabitants, lies across the caldera borders. In recent years Campi Flegrei caldera has experienced an accelerating uplift rate of the ground deformation. In particular, during the April 2012 - January 2013 time interval the caldera has shown a rapid uplift of about 6 cm with a peak rate of about 3 cm/month in December 2012. This event led the Italian Civil Protection to raise the alert level of the volcano from green to yellow. We exploited the displacement time series obtained by processing 90 SAR images acquired from the COSMO-SkyMed sensor constellation along ascending orbits via the well-known DInSAR algorithm referred to as SBAS algorithm, and the measurements provided by 14 continuous GPS stations deployed within the caldera and belonging to the permanent INGV-OV monitoring network. To study the detail of the intrusion process we have applied novel geodetic imaging technique to determine the spatial and temporal kinematics of the ground deformation source in the selected period. The retrieved temporal pattern of the source geometry reflects that of a growing sill which, at the end of the considered period, has a roughly elliptical geometry with an extension of about 6 km in the EW direction and about 4 km in the NS one. The maximum aperture of the sill is of about 30 cm at its center. To understand the dynamics of this phenomenon we used a recently developed numerical model of the emplacement of a magmatic sill, to fit the retrieved geometry. The parameters to be determined are: the average magma viscosity, the amount of magma already present in the sill before the 2012-2013 episode and the magma injection rate. Results show that the most likely value for the viscosity is between 103 − 104Pa · s and that to justify the observed deformation pattern it is required that the reservoir should have contained at least 1010kg of liquid magma before 2012. The injection rate has two main peaks on September and December 2012, and a smaller one on March 2013. The first two peaks have a value of about 400 kg/s and duration of 3-4 months. The total amount of injected magma is of about 8.2 · 1010kg. The magma viscosity value is compatible with that of the most common magmas erupted in the past 40 ky: phonolites, while the total inferred amount of liquid magma is of the same order of magnitude of small-size eruptions (VEI 2-3) occurred in the caldera during the last 15 ky. The first injection peak is associated with a seismic swarm, located beneath the town of Pozzuoli. The swarm consisted in about 200 earthquakes (maximum magnitude 1.8) occurring within an interval of about 1.5 hours. The hypocenters were located outside the area usually affected by microearthquakes in the previous years. Using finite element structural mechanical modeling we show that the inferred source caused a marked increase in the maximum shear stress along the rim of the sill. In fact hypocenters were located very close to the northern edge of the growing magmatic reservoir. Our findings suggest a key to interpret the caldera unrest that, started about 60 years ago, has led to a maximum uplift in the area of more than 3 m. Consequently, the observed uplift phenomenon could be interpreted in terms of injection of limited magma batches feeding the growth of a shallow magmatic reservoir. Similar mechanisms have been inferred for other calderas, where the repeated emplacement of magmatic sills has been recognized having an important role in the evolution of the volcano. Accordingly, the observation of short evolution of volcanic precursory phenomena as well as the development of innovative real- time analysis techniques should be taken into account for an effective surveillance of the Campi Flegrei caldera. This work has been supported by the Italian Department of Civil Protection and by the Italian Space Agency under theSAR4Volcanoes project (agreement n. I/034/11/0) and by MED-SUV project (European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 308665).

Beschreibung: Published

Beschreibung: Vienna

Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi

Beschreibung: open

Beschreibung: This work arises from the field observations made during the civil protection emergency period connected to the 2007 Stromboli eruption. We observed changes in the shallow feeding system of the volcano to which we give a volcanological interpretation and the relative implications. Here we describe the processes that occurred in the upper feeding system from the end of the 2007 effusive eruption on 3 April to the renewal of the strombolian explosive activity at the summit craters (30 June), interpreted using multidisciplinary data. We used thermal camera data collected both from helicopter and from a fixed station at 400 m to retrieve the evolving summit crater activity. These data, compared with seismic signals and published geochemical records, allowed us to detail the shifting of the degassing activity within the crater terrace from NE to SW, occurred between 15 and 25 April 2007 prior to the resumption of the strombolian activity. In particular, from mid-April, a gradual SW displacement in the maximum apparent temperatures was recorded at the vents within the summit craters, together with a change in the very long period location and confirmed by variations in geochemical indicators (CO2∕SO2 plume ratios and CO2 fluxes) from literature. The shallow feeding system experienced a major readjustment after the end of the effusive activity, determining variations in the pressure leakage of the source, slowly deepening and shifting toward SW. All these data, together with the framework supplied by previous structural surveys, allowed us to propose that the compaction of debris accumulated in the uppermost conduit by inward crater collapses, occurred in early March, produced the observed anomalies. At Stromboli, major morphology changes, taking place in the following years, were anticipated by these small and apparently minor processes occurred in the upper feeding system. Other studies are relating similar changes to modifications of the eruptive activity also at other open-conduit volcanoes, so we believe that it may be important to have a constant monitoring of these phenomena in order to better understand their shallow feeding systems.

Beschreibung: This paper was partially supported by a grant to S.C. (Project INGV-DPC Paroxysm V2/03, 2008–2010) funded by the Istituto Nazionale di Geofisica e Vulcanologia and by the Italian Civil Protection.

Beschreibung: Published

Beschreibung: 7376–7395

Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi

Beschreibung: JCR Journal

Beschreibung: restricted