ALBERT

Description: Ischia is a densely inhabited and touristic volcanic island located in the northern sector of the Gulf of Naples (Italy). In 2017, the Mw 3.9 Casamicciola earthquake occurred after more than one century of seismic quiescence characterized only by minor seismicity, which followed a century with three destructive earthquakes (in 1828, 1881, and 1883). These events, despite their moderate magnitude (Mw 〈 5.5), lead to dreadful effects on buildings and population. However, an integrated catalogue systematically covering historical and instrumental seismicity of Ischia has been still lacking since many years. Here, we review and systematically re-analyse all the available data on the historical and instrumental seismicity, to build an integrated earthquake catalogue for Ischia with a robust characterization of existing uncertainties. Supported by new or updated macroseismic datasets, we significantly enriched existing catalogues, as the Italian Parametric Earthquake Catalogue (CPTI15) that, with this analysis, passed from 12 to 57 earthquakes with macroseismic parametrization. We also extended back by 6 years the coverage of the instrumental catalogue, homogenizing the estimated seismic parameters. The obtained catalogue will not only represent a solid base for future local hazard quantifications, but also it provides the unique opportunity of characterizing the evolution of the Ischia seismicity over centuries. To this end, we analyse the spatial, temporal, and magnitude distributions of Ischia seismicity, revealing for example that, also in the present long-lasting period of volcanic quiescence, is significantly non-stationary and characterized by a b-value larger than 1.

Description: The island of Ischia has a land area of 46.3 square kilometers and a population of 64.115 inhabitants by 2019. The territorial density is 1,385 inhabitants per square kilometer. The environmental sustainability of Ischia is about 22 thousand inhabitants. In the year 2017 there were about 2.3 million tourists. The remarkable expansion of historical settlements on the Island in recent decades, without adequate planning that would pay attention to the geological hazard, has produced an exponential increase in risk, as it was shown by the disastrous earthquake that occurred in Casamicciola on 21 August 2017. The underestimation of volcanic, seismic and hydrogeological risks on the Island is incomprehensible due to the catastrophes that occurred with the historic eruption of 1302, the strong earthquakes of 1881 and 1883 and the disastrous flood of 1910.

Description: Published

Description: PARMA

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: Abstract – The Campanian Plain: a geological monument of 5.000 km2 from the Tyrrhenian Sea to the Apennines - The Campanian Plain is the region in Southern Italy which extends between the Apennine Chain and Tyrrhenian Sea over an area of 5,000 km2 from Mt. Massico, in the north, to Sorrento Peninsula in the south of the Plain. The ancient name of this area was Campania Felix. This territory is an extraordinary geological monument characterized by volcanoes, earthquakes, tsunamis, slow ground vertical movements (bradiseism) which generated myths, legends, archeological findings, historical documents. The Campanian Plain is affected by extensional tectonics related to the spreading of the Tyrrhenian Basin. The onset of this process occurred between the Mid–Pliocene and the Early Pleistocene, when large morpho-structural depressions began to develop, giving rise to the Bay of Naples. The whole range of phenomena observed, in particular the recent tectonics and chemism of magmas feeding active volcanoes can be accounted for the local upwelling of the Mantle, the lytosphere plate bending and subsequent collapses. The measure of the collapse in the Campanian Plain, due to the stretching of the crust produced by the Mantle migration, is obtained by the thickness of sediments forming Campanian Plain. These data and the time lapse of the process furnish a value of about 1-2 mm/yr for the velocity of the subsidence during the Quaternary. Coeval to the deformation of this morphostructural depression was the onset of intense magmatic activity with the formation of the polygenic apparatus of Mt. Vesuvius and the volcanic fields of Phlegraean Fields and Ischia Island. In the Phlegrean Fields and Ischia caldera collapses, ignimbrite eruptions, and caldera resurgences occurred; instead at Vesuvius numerous Plinian eruptions were recorded. The most recent eruptions in the Neapolitan area occurred in 1302 at Ischia, 1538 at Phlegrean Fields and 1944 at Vesuvius. At present large fumarolic fields and thermal springs outcrop in several sites, while in the Phlegrean Fields slow oscillations of ground are recorded. The eruptive history of neapolitan volcanoes, the seismic history of Southern Appennines as well as the geological features of Campanian Plain characterize this area as a geological multirisk territory. Thus it is a “laboratory” for volcanic, seismic and hidrogeological risk assessment, from wich to draw lessons for integrated planning of pleasant places in risk areas.

Description: Published

Description: Bologna

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: The Royal Observatory of Vesuvius (ROV) is the oldest volcanological observatory in the world. It was founded in 1841 by the King of the Two Sicilies, Ferdinand II of Bourbons, in order to study the volcanic activity of Vesuvius for the early warning of the population. Currently, it hosts a permanent exhibition where the visitors are introduced to volcanism and its hazards, the monitoring systems of active volcanoes, and the history of Mt. Vesuvius and the Vesuvius Observatory. It provides an integration between conventional and innovative exhibitions, by implementing the wonderful collections of rocks and minerals, old books, historical instruments, documents and paintings, with computer graphics and multimedia installations. After a long period of about one year – when renovation works were closed – the ROV reopened with a magnificent ceremony, where the rooms of the Museum also hosted an art and photography exhibition by the students of the Karlsruhe Art Academy, the Architecture Faculty of the Zurich University and the Hamburg Academy. The ROV reopening to the public fits in a much wider process of requalification of the Vesuvius region, where, the dissemination of the knowledge of the volcano will promote the proper use of its territory, not only to blow up all the potential of the area, but also to prepare future generations for a more conscious and fruitful use of the resources offered by the area.

Description: Published

Description: 114-131

Description: 2TM. Divulgazione Scientifica

Description: N/A or not JCR

Description: A ML=4.9 earthquake occurred in the Sannio-Matese area at 18:08 on December 29 2013. The epicenter was located in the “Monti del Matese seismic district”. The epicentral area lies between the small towns of San Gregorio Matese, Cusano Mutri, Gioia Sannitica, Piedimonte Matese, San Potito Sannita in the Caserta province in an area with an high seismic Hazard. The area was struck by large and destructive earthquakes in the past (1456, 1688, 1702, 1732, 1805,1962) with maximum magnitude up to 7.2. Past and recent seismicity of the area is generally characterized by both single events and low energy seismic sequences (1885, 1903, 1905, 1990, 1992, 1997). The last sequence occurred on 1997 with the largest event (MD = 4.1, 19 March) occurred at the border between the Benevento and Campobasso provinces followed by an intense activity ended only in September of the same year. The epicentral distribution of the 1997 low energy (M ≤ 4.0) seismic sequence is mainly NE-SW oriented suggesting the activation of anti-Apennine faults. The December 29 2013 seismic event, is located very close to the 1688 earthquake area. Still open debate is the association of the main event of the sequence and its aftershocks with the seismogenic structures present in the area. The SAGNET (Southern Apennine Geodetic NETwork) is the Non-permanent GPS network covering the area between the Matese Mounts and the Mainarde–Meta Mountains and consists of 40 3D GPS vertices. GPS dataset consists of data recorded at non-permanent stations in the time spam 2002-2014 and at the Continuous GPS stations (CGPS) of the RING network (managed of INGV) located in the central and southern Apennines regions. We have calculated the GPS velocity field with permanent and non-permanent stations (with time series of at least 3 surveys). The horizontal velocity field, expressed with respect to a fixed Eurasian plate, shows a good coherence between the velocities field estimated from the SAGNET and CGPS. In this paper we have evaluated the strain rate in the Sannio-Matese area. Before the earthquake, GPS data analysis showed a decrease in the velocity in the southern sector of Matese Massif (where the December 29 2013 earthquake epicenter will be localized) with respect to the surrounding areas which is also evident from the lower values of the strain rate ranging between 15÷20 *10-9 yr-1. Lower GPS Strain rate has been recognized at the end of seismic cycle and appear as a useful tool to point out hazardous seismic areas as already highlighted in the 2009 L'Aquila and in the 2012 Emilia earthquakes.

Description: OGS - ENI - Dip. Scienze della Terra "Ardito Desio"

Description: Published

Description: Milano

Description: 3T. Pericolosità sismica e contributo alla definizione del rischio

Description: open

Description: This paper analyses data regarding the seismicity and ground deformations of the island of Ischia. The goal is to describe these phenomena as a space–time process, exploring the mechanism as a whole in order to answer questions concerning why and how historical earthquakes occurred and the geological constrains at the time of the earthquake of 21 August 2017. According to our analysis, the genesis of earthquakes in the island may be due either to regional tensile tectonics or to increased pressure in a shallow magma source. The eruptive rest following the 1302 Arso lava flow, the seismic silence from 1883 and the ground sinking recorded at least from the end of the nineteenth century suggest a decline of pressure in the shallow magma source and in the action of the stress field generated by the spreading of the Tyrrhenian Basin. The mechanism that can generate the observed ground deformation field and seismicity is the gravitational and thermal loading of the island, because the load of the massif of Mt. Epomeo onto its hot substratum may induce the gravitational spreading that would have produced its sliding southwards and its rotation northwards. The surface of detachment plunges towards the south and emerges at a high angle at the northern edge of Mt. Epomeo, where coseismic ground effects and the greatest damage have been observed. This mechanism that generated the 21 August 2017 earthquake could be extended to historical seismicity.

Description: Published

Description: 955-994

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: JCR Journal

Description: The last Vesuvius eruption on March 1944, closed a 300 years long period of intens the eruptiv eactivity, began immediately after the 1631 AD sub-plinian event

Description: Published

Description: Nicolosi (Catania)

Description: 3V. Dinamiche e scenari eruttivi

Description: open

Description: In this study the mentioned ash samples are analyzed for the first time in order to explore eruptive dynamics. Such ash samples belong to the Vesuvius Observatory Museum, where there is a rich collection of volcanic ash emitted by the Vesuvius volcano during the period of open-conduit activity that has preceded the last 1944 eruption.

Description: Published

Description: Napoli

Description: 1V. Storia eruttiva