Porfido, Sabina

More than forty years after the 23 November 1980 earthquake, which devastated the Campania and Basilicata regions, causing the destruction of a large number of towns and the death of around three thousand people, we have tried, through a large survey, to understand how and to what extent the urban fabric and the most affected communities have been rebuilt. Our main objective was to show, on one side, the commitment of the scientific community, and on the other the transitions that have led from the emergency to reconstruction. Of the Apenninic towns Conza della Campania, Laviano, Lioni, Santomenna, and others, where the devastation was almost total, we have tried to give an iconographic vision of the post-earthquake phase through the change in the urban layout. The partial or total reconstruction of the towns has taken place most of the time in situ, only in some cases by relocating buildings to neighboring areas, as happened in Conza della Campania, Bisaccia and Romagnano al Monte. Reconstruction was carried out mainly of anti-seismic buildings and only in some cases recovering preexisting buildings in historic centres; reconstruction was completed after a very long period, in some cases lasting over thirty years, inevitably passing through a dramatic experience of the population in temporary settlements of various kinds, from tents, caravans, railway carriages, to containers, and finally to thermo-igloos and to prefabricated wooden chalet-type. A very complex and detailed reconstruction was linked to factors not only territorial, economic and political but also conditioned unfortunately by the non-negligible intervention of organized crime.

Earthquake environmental effects may significantly contribute to the damage caused by seismic events; similar to ground motion, the environmental effects are globally stronger in the vicinity and decrease moving away from the epicenter or seismogenic source. To date, a single intensity prediction equation (IPE) has been proposed in the Italian Apennines for intensity scale dealings with environmental effects: the Environmental Seismic Intensity (ESI-07). Here, we evaluate the sensitivity of the IPE with respect to input data and methodological choices and we propose IPEs with global validity for crustal normal faults. We show the strong influence of input data on the obtained attenuation investigating the 1980 Irpinia–Basilicata (Southern Italy) earthquake. We exploit a dataset of 26 earthquakes to build an IPE considering the epicentral distance. We also propose an IPE considering the distance from the fault rupture, which is derived from a dataset of 10 earthquakes. The proposed equations are valid for normal faults up to 40 km from the epicenter/fault and may flank other models predicting ground motion or damage to the built environment. Our work thus contributes to the use of the ESI-07 scale for hazard purposes.

Coniolo and Brusaschetto, are two small towns located in the Monferrato area of the Alessandria Province, northern Italy. These communities have similar histories related to develop ment and subsequent abandonment of marl quarry activity that began more than a century ago and continued until recently. Quarrying occurred until soil conditions, water infiltration, and excessive depth made cost of extracting and7 lifting material prohibitive. Quarries consisted of tunnels located directly beneath the towns at about 150 m below ground surface. Collapse of the tunnels led to surface subsidence and destruction of overlying homes and much of the municipal infrastructure. In the early Twentieth Century, regulations pertaining to mine and quarry safety were typically deficient, entirely absent, or not followed. Extractive activities of non-energy mineral resources from quarries and mines were and continue to be widespread in Italy, which currently ranks fifth among what are now countries of the European Union (EU). Mining sites are present in all regions of Italy, particu larly in the northern part of the country and along coasts, often in areas of geohydrogeological risk. Consequences of anthropogenic pressures that alter the natural environment, such as the physical size of aquifer drawdowns, are linked to issues for a number of extractive sites across the country. This report analyzes historical and technical documents, conducts a geomorphological analysis of hilly slopes surrounding these communities, and examines urban planning and geophysical surveys to determine the impact of subsurface quarrying activities on the overlying ground surface. The study highlights significant problems that are applicable to other localities globally. This research demonstrates: (a) the importance of geological considerations to development and abandonment of mining activity in inhabited areas; (b) the importance of establishing and following safety protocols; and (c) the manner in which economic interests can take precedence over the well-being and lives of those employed to extract resources.

This paper demonstrates how historical research is a valuable tool for identifying past geological, geomorphological and climatic hazards and therefore critical for mitigating and reducing future risk. The authors describe the potential of a scientific field that straddles that of the geologist, geographer, historian and archivist. Historical records include a range of materials and sources of information, which can be very diverse; from written documents to cartographies, and from drawings to marble tombstones. They are all useful and convey important data, on the date of the event, the size of the phenomena, sometimes on ground effects, damage or magnitude. The authors discuss how to conduct historical research by providing a list of locations and how important historical documents can be found. Works that mention geological phenomena are listed, starting with the first occasional descriptions by individuals in letters, up to very specific publications in individual fields of interest. With this introduction, the editors of the Special Issue wish to draw attention to the importance of historical documentation, which is too often ignored or considered of low priority by the scientific community, but can contain key information on events, their impacts and social and cultural adaptations.

The 28th September 2018 Sulawesi Supershear earthquake (MW 7.5) was one of the deadliest earthquakes in the recent history of Indonesia causing ∼4000 causalities. The earthquake caused a ∼ 177 km long surface rupture along the Palu-Karo fault. Apart from surface rupture, the earthquake caused extensive earthquake environmental effects (EEEs) around the Palu-Donggala area of Central Sulawesi, Indonesia, which includes tsunami, coastal landslide, liquefaction, ground cracks and more than 7300 landslides in hilly areas. Initial post-event analysis and reports assigned a Modified Mercalli Intensity (MMI) of VII to VIII in Palu City and the surrounding area. Building damage and ground effects caused by the earthquake suggested that seismic intensity was understated. Here we applied the EEEs information from field survey data, published reports, and remote sensing tools to determine macroseismic intensity using the Environmental Seismic Intensity (ESI-07) Scale. The ESI-07 intensity derived from the ground effects suggests the maximum intensity of X-XI, which is 3–4° higher than the traditional intensity estimated by the United States Geological Survey (USGS) and the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). ShakeMaps were generated considering the ESI-07 values. The ShakeMap was compared with the instrumentally derived ShakeMap for the Palu earthquake, which proves that the ShakeMap prepared from the instrumental data or structural damage data is underrated. We argue that proper documentation of the EEEs is necessary for such damaging earthquakes for future earthquake hazard mapping and planning in the study area and other earthquakes in Indonesia. In addition, this will help in defining the on-fault and off-fault damage zone towards reducing the seismic risk of the Palu Donggala area.

On December 26, 2018 (2:19 UTC), during a volcanic eruption on the Mt. Etna eastern flank (Sicily, southern Italy), the largest instrumental earthquake ever recorded in the volcano ruptured the Fiandaca Fault, with epicenter between Fleri and Pennisi villages (hypocenter at ca. 300 m a. s. l., Mw 4.9). This was the mainshock of an earthquake swarm and it was accompanied by widespread surface faulting and extensive damage along a narrow belt near the fault trace. Few hours after the mainshock, an episodic aseismic creep event occurred along the Aci Platani Fault, a SE extension of the Fiandaca Fault, which caused several damages in the Aci Platani village. We surveyed and mapped the coseismic and aseismic ground ruptures, and collected structural data on their geometry, displacement, and fault zone fabric. We compared the mapped surface ruptures with topography, lithology, and morphology of the buried top of the sedimentary basement. We conclude that the geometry of the volcanic pile influenced the surface expression of faulting during the December 26, 2018 event. The top surface of the marly clay basement should be considered as a detachment surface for shallow sliding blocks. The earthquake occurred on top of a depression of the sedimentary basement forcing the sliding eastward, causing at surface the re-arrangement of the fault strand pattern and deformation style, switching from shear faulting to a tensile failure. The Fleri earthquake therefore provides an unprecedented dataset for 1) understanding active faulting in the European largest onshore volcano, 2) modeling its complex dynamics, and 3) contributing to a more refined surface faulting hazard assessment at Mt. Etna. Results from this investigation might be useful for characterizing capable faulting in similar volcano-tectonic settings worldwide.

This reprint "The November 23rd, 1980 Irpinia-Lucania, Southern Italy Earthquake: Insights and Reviews 40 Years Later” presents a collection of 13 scientific contributions proposed by 44 researchers with different expertise and multidisciplinary approach highlighting the most important aspects of the Irpinia-Lucania earthquake (Ms 6.9, Io X MCS) from a seismological and geological point of view, without neglecting the reconstruction of cultural heritage, the resilience of the population, and the socioeconomic development of the internal areas of the Southern Apennines after the earthquake. The 1980 earthquake struck Irpinia-Lucania region (Southern Italy) and it is remembered in Italy not only for being the strongest earthquake recorded in the last 100 years causing devastation of entire regions and severe loss of human life, but also for the destruction of the cultural heritage in the epicentral area. This volume, far from being exhaustive, nevertheless wants to be an important point of reference for the new generations of researchers who will have both a historical and multidisciplinary approach to the knowledge of this earthquake.

Many Italian cities and towns have been affected by geological or geohydrological processes. However, due to the loss of historical memory, lessons of the past have been ignored; new urbanized areas have expanded into the same zones where damage and casualties occurred in the past. Despite current practices, researchers are showing how historical data can be among the most valid tools for identifying the most affected and hazardous areas. When the completeness and quality of historical sources are sufficiently high, we can make useful statistical inferences regarding the spatiotemporal variations of natural processes. This information is of great importance for land use planning, as it makes us able to rely not only on the current state of the investigated areas but also on their dynamic evolutionary framework over time. In this article, we present a chronological review of past Italian works describing the occurrence of natural extreme events making use of historical data. Then, we present some Italian case studies in which the awareness of hazards gained by paying attention to past information would have ensured better management of the risk for the benefit of public safety. Finally, the authors stress the need to safeguard, manage, and enhance the large collection of historical data that constitutes Italy’s heritage.

After more than forty years since the 1980 Irpinia-Lucania earthquake, with this Special Issue “The November 23rd, 1980 Irpinia-Lucania, Southern Italy Earthquake: Insights and Reviews 40 Years Later” we revisit this milestone geological and seismological event, bringing together the latest views and news on this earthquake, with the aim of improving the dissemination of wide-ranging information on this remarkable case history.

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.