Search

The use of Micro Fibrillated Cellulose (MFC) as filler for polymeric matrices attempts an increasing interest both in academia and industry. In this framework, encouraging results have been obtained using plasticizers, as dispersing aids, during twin-screw extrusion that optimizes the process parameters and avoid MFC agglomeration. In this work, two commercial typologies of waterborne solution of MFC (Exilva and Celish) were melt-compounded in a PLA matrix through semi-industrial twin-screw extruder and calendered, producing films of 150 μm thickness. These films were mechanically and thermally characterized, moreover the migration of the plasticizer along the time was evaluated through analytical model and the diffusion coefficient was calculated.

We report on a systematic record of SO2 flux emissions from individual vents of Etna volcano (Sicily), which we obtained using a permanent UV camera network. Observations were carried out in summer 2014, a period encompassing two eruptive episodes of the New South East Crater (NSEC) and a fissure‐fed eruption in the upper Valle del Bove. We demonstrate that our vent‐resolved SO2 flux time series allow capturing shifts in activity from one vent to another and contribute to our understanding of Etna's shallow plumbing system structure. We find that the fissure eruption contributed ~50,000 t of SO2 or ~30% of the SO2 emitted by the volcano during the 5 July to 10 August eruptive interval. Activity from this eruptive vent gradually vanished on 10 August, marking a switch of degassing toward the NSEC. Onset of degassing at the NSEC was a precursory to explosive paroxysmal activity on 11–15 August., Key Points Records of SO2 flux emissions from Etna's individual vents allow capturing shifts in volcanic activityVent‐resolved SO2 flux time series provide constraints on geometry of the shallow plumbing systemVent‐resolved SO2 flux time series demonstrate SO2 flux increase precursory to paroxysmal (lava fountaining) activity

We present the first results of a preliminary geological and geophysical survey carried out in the archaeological site of Santa Venera al Pozzo (Catania, Italy). The site dates back to the Roman Age, (1st century BC). Geological surveys highlighted a set of remarkable fractures affecting some archeological remains, suggesting the occurrence of a capable fault zone through the area. Multidisciplinary geophysical surveys (seismic refraction and electrical resistivity tomographies, together with aerial photographic and thermographic survey) identified a main tectonic discontinuity ascribable to the fault zone, allowing us to infer that the fractures observed at surface could be the evidence of coseismic ruptures.

In the present paper we describe the on-land field operations integrated in the TOMO-ETNA experiment carried out in June-November 2014 at Mt. Etna volcano and surrounding areas. This terrestrial campaign consists in the deployment of 90 short-period portable three-component seismic stations, 17 broadband seismometers and the coordination with 133 permanent seismic station belonging to Italy’s Istituto Nazionale di Geofisica e Vulcanologia (INGV). This temporary seismic network recorded active and passive seismic sources. Active seismic sources were generated by an array of air-guns mounted in the Spanish oceanographic vessel “Sarmiento de Gamboa” with a power capacity of up to 5200 cubic inches. In total more than 26,000 shots were fired and more than 450 local and regional earthquakes were recorded. We describe the whole technical procedure followed to guarantee the success of this complex seismic experiment. We started with the description of the location of the potential safety places to deploy the portable network and the products derived from this search (a large document including full characterization of the sites, owners and indication of how to arrive to them). A full technical description of the seismometers and seismic sources is presented. We show how the portable seismic network was deployed, maintained and recovered in different stages. The large international collaboration of this experiment is reflected in the participation of more than 75 researchers, technicians and students from different institutions and countries in the on-land activities. The main objectives of the experiment were achieved with great success. © 2016 by the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved.

An ongoing archaeological investigation at Stromboli shows a complex pattern of human occupation of the north eastern sector of the island (San Vincenzo plateau), which allowed an excellent strategic control of the southern Tyrrhenian sea. This interdisciplinary project focus on the stratigraphic sequences, formation processes, artifacts, raw materials and circulation networks. We aim at building a chronological framework integrating archeological, volcanological and historical studies with several methods of absolute chronology (14C, archaeomagnetic and cross-datings). First human occupation of Stromboli is attested by the presence of some prehistoric shards of the Spatarella facies, dated 3500 BC (late Neolithic-early Eneolithic). More abundant remnants of this phase are recorded in the opposite side of the island (Ginostra). Main archaeological evidences are related to a Bronze Age village characterized by rounded huts with stone walls (organized on several terraces) built upon lavas and scoriae dated by archeomagnetism at 6.2 ka ago. It is worth to note these lavas are directly covered by the pyroclastics of the “Secche di Lazzaro” eruption occurred, at ca. 6 ka ago. Artifacts belong to the Capo Graziano facies (Early to Middle Bronze Age 1-2): decorated and undecorated handmade burnished pottery and some imports from the Aegean. The 14C datings of more than 20 layers show a range between 2290- 1475 BC (2 sigma cal. age) attesting for a long lasting human occupation. Radiocarbon datings also show that the settlement of San Vincenzo started at the beginning of Capo Graziano I, with a significant presence during the early periods. The typological variability of the local and the Mycenaean pots seems to confirm this chronology. After the Bronze Age period there are no evidence of human activity on Stromboli, whereas other islands of the Aeolian Archipelago were occupied until the end of the Middle Bronze (1300 BC) or Final Bronze (900 BC; Lipari) Age. New life on Stromboli is attested during the classical phases: a Greek necropolis (320-250 BC) and Roman late Imperial age evidence (II-IV AD). A well preserved, up to 10-15 cm thick, purplish to black layered fallout deposit was discovered in the excavation, covering a channel containing green glazed pottery dated XIV-XV century AD. An origin from a Stromboli paroxysm during the XVI century is strongly supported by three 14C dated charcoals (1325-1520 AD, 2 sigma cal. age) from the layers immediately below the ash fallout. Some authors suggested 1558 for a Stromboli paroxysm but this is not strengthened by historic accounts (e.g. Tommaso Fazello).

Reconstruction of the sequence of the landslides that occurred soon after the beginning of the December 2002 eruption on the NW flank of the Stromboli volcano.

The 17 January 2002 fissure eruption of Mount Nyiragongo, Democratic Republic of Congo, produced lava flows which entered and devastated the densely inhabited town of Goma. The 2002 and previous 1977 eruptions demonstrate the high level of volcanic risk in the area. We present an analysis of the susceptibility to lava flow invasion in Goma, by means of computer simulations based on the steepest descent path and probabilisticcomputed flow spreading and obstacle overcoming. The DEM is obtained from a topographic map of Goma by using the DEST algorithm. The numerical results show the distribution of probable lava flow paths from possible vents in the investigated topographic domain. Numerical simulations are validated through comparison with the mapped paths of the 2002 lava flows in Goma. The subsequent investigation includes the analysis of (1) hypothetical lava flow paths from ephemeral vents on the edge of the 2002 lava flows, (2) paths from venting along the hypothetical extension of the 2002 fissures, (3) paths in case of lava flow arrival in town from the north, and (4) changes induced by the presence of the solidified 2002 lava field. The results show the susceptibility of the different parts of the town of Goma to be invaded by future lava flows, and reveal the existence of a large area in town with minimum susceptibility and which can be invaded only in case of venting within it. The areas destroyed by the 2002 lava flows are predicted to be characterized by maximum susceptibility to lava flow invasion.

Applicazione della fotogrammetria digitale a problemi legati alla stabilità del versante del vulcano Stromboli

The complex sequence of large-scale tsunamogenic instability phenomena occurred on the subaerial and submarine NW flank of the Stromboli Volcano soon after the beginning of the December 2002 eruption is reconstructed and its relationship with volcanic activity is evidenced. After a brief description of slope morphology and stratigraphy, geometry and kinematics of the landslides are described. Finally, instability mechanisms that controlled the subaerial and submarine slope failures are proposed with reference to the different geotechnical, hydraulic, and loading/strain conditions that characterized the different stages of the slope evolution.