THE 23 JULY 1930 EARTHQUAKE (MS=6.7) IN THE SOUTHERN APENNINES (ITALY): GEOLOGICAL AND HYDROLOGICAL EFFECTS

The 23 July 1930 earthquake (MS=6.7) in the Southern Apennines (Italy) was a catastrophic event that produced many effects such as surface faulting, fractures, landslides, settlements, hydrological changes, variations in chemical/ physical activity related to the volcanic and/or thermal zones and also acoustic and optical phenomena. It is the first great earthquake of the twentieth century that was studied, thanks to the hydrological monitoring network of the Italian Hydrographic Survey (IHS) set up from 1925 to 1929. For this earthquake we analysed the initial IHS hydrometric and pluviometric data, looking for significant anomalies in springs, water wells and mountain streams. Hydrological data relative to rivers, springs and water wells indicate that some changes can be correlated with the earthquake: a post-seismic excess discharge in some streams, pre- and co-seismic decreases in stream flows and water levels in wells, pre- and post-seismic increases in discharges. The pre- and co-seismic stresses and the tectonic deformations were studied in order to find a possible model of interaction between stress state and hydrological variations. The anomalies found in this work can be considered “rebound anomalies”, which are the most common precursor reported by several authors and related to increases in porosity and permeability caused by the fracturing that precedes an earthquake. An estimation of the total excess discharge (0.035 km3) caused by the Ms=6.7 Irpinia earthquake is consistent with the excess discharge of about 0.01 km3 determined for the Mw=6.9 Loma Prieta earthquake. To define the normal hydrodynamic behaviour of the considered aquifers, an analysis of the correlation between rainfalls and water levels and flow rates has been carried out. The delay of significant peaks in the correlograms of figure 7 with respect to the start of the hydrological anomaly and/or its duration, can define the space-time limits of the changes correlated with earthquake

Hydrological anomalies connected to earthquakes in southern Apennines (Italy)

The study of hydrological variations in the watersheds of seismic areas can be useful in order to acquire a new knowledge of the mechanisms by which earthquakes can produce hydrological anomalies. Italy has the availability of many long historical series both of hydrological parameters and of seismological data, and is an ideal laboratory to verify the validity of theoretical models proposed by various authors. In this work we analyse the hydrological anomalies associated with some of the big earthquakes that occurred in the last century in the southern Apennines: 1930, 1980 and 1984. For these earthquakes we analysed hydrometric and pluviometric data looking for significant anomalies in springs, water wells and mountain streams. The influence of rainfalls on the normal flows of rivers, springs and wells has been ascertained. Also, the earthquake of 1805, for which a lot of hydrological perturbations have been reported, is considered in order to point out effects imputable to this earthquake that can be similar to the effects of the other big earthquakes. The considered seismic events exhibit different modes of energy release, different focal mechanisms and different propagation of effects on the invested areas. Furthermore, even if their epicentres were not localised in contiguous seismogenetic areas, it seems that the hydrological effects imputable to them took place in the same areas. Such phenomena have been compared with macroseismic fields and transformed in parameters, in order to derive empirical relationships between the dimensions of the event and the characteristics of the hydrological variations. The results of this work point to a close dependence among hydrological anomalies, regional structures and fault mechanisms, and indicate that many clear anomalies have been forerunners of earthquakes. In 1993, the Naples Bureau of the Hydrographic National Service started the continuous monitoring of hydrologic parameters by a network of automatic stations and transmission in real time; presently 7 acquifers are under control in which also pH, <i>T</i> , salinity, electrical conductivity, dissolved oxygen are measured. We envisage to increase the number of monitoring sites and controlled parameters

The use of documentary sources for reconstructing flood chronologies on the Amalfi rocky coast (southern Italy)

Documentary source materials are essential for retrospective reconstruction of flood events occurring in past centuries. This paper presents methods of research and archiving of historical data from the 16th century to the present. The quality and completeness of the various original sources were evaluated and carefully analysed in their historical context, to avoid serious mistakes. Systematic investigation of about 3000 documents, mainly found in national State Archives and libraries, allows us to identify and localize at least 106 flood events occurring along the Amalfi coast (southern Italy) for five centuries between the years 1500 and 2000. The collected data provide useful details on flood dynamics, size of flooded areas, flood duration, damage level, number of victims and induced geological effects. When available in sufficient quantity, the flood data allow determination of very useful parameters such as the severity class, to identify large floods and their recurrence interval

Flood Historical Data for Flood Risk Estimation in Coastal Areas, Eastern Tyrrhenian Sea, Italy

A reconstruction of historical floods occurred along the Amalfi coast, during the last five 7 centuries is presented. The analysis of historical sources allowed to achieve a chronological 8 reconstruction of more than 100 floods, four of which classified as catastrophic events. In this 9 task, the level of information was decisive to carry out space–time identification, estimate the 10 affected area and define the type of damage to the structures, and the environment (e.g. mud 11 flow, debris flow, rock falls, shoreline progradation, fan deltas), which may be relevant for the 12 recognition of similar events within the geologic record. The magnitude of the events was 13 finally estimated, taking into account the size of the areas affected by flooding as well as the 14 type of effects induced on the urban and physical environment and the recurrence intervals

The geological record of storm events over the last 1000 years in the Salerno Bay (Southern Tyrrhenian Sea): new proxy evidences

International audienceThe shallow marine Late Holocene wedge of the northern Salerno Bay shelf (Southern Tyrrhenian Sea) discloses the presence of four decimetric shelf-tapering sand beds. Their internal features, depicted by cores analysis and their stratigraphic position, revealed by VHR seismic investigations, inferred sandy layers as being the result of flash deposition, storm controlled, thus episodic. Stratigraphic correlations among cores lead to constrain sandy layers deposition to storm events falling in the 11th, 16th, 19th and 20th centuries. A certain attribution of the most recent event bed to the major cloudburst that hit the Salerno region in 1954A.D. and resulted in a disastrous flood of the Bonea stream, was formerly achieved. A tentative link with two sea-storms that occurred in the 1544A.D. and in the 1879A.D. and well documented by historical sources is here proposed to explain the deposition of the two previous event beds. The deposition of these sandy layers must be related to major storm events, since their preservation in the stratigraphic record is not common. Lithostratigraphic and textural differences between flood and sea-storm emplacement emerge from the study of sandy layers in cores and point to a prevalence of sea-storm deposits in the middle shelf compared to flood deposits. Seismic stratigraphic evidence lead us to suppose that the style of episodic flash deposition has been running on for the last 2-3kyr and is probably linked to a climatic trend of the region

Seismically induced ground effects of the 1805, 1930 and 1980 earthquakes in the Southern Apennines (Italy

Seismically induced environmental effects (in particular, surfacefaults, ground cracks, slope failures, liquefaction, soil compaction, hydrological changes, tsunamis) are assumed to provide fundamentalinformation on the earthquake size and its intensity field, crucial for a more efficient seismic hazard assessment. Accordingly, this study is aimed at substantiating this assumption by showing that the knowledge about ground effects acquired in recent earthquakes, when combined with that illustrated in historical documents, allows to buildan improved picture of historic seismic events, with respect to that usually provided by the solely damage-based macroseismic scales. In this perspective, the environmental effects are analysed and cataloguedof three of the most ruinous earthquakes in Southern Italy of the last two centuries: the July 26,1805, Molise event (XI MCS, M 6.8), the July 23, 1930, Irpinia event (X MCS, M 6.7), and the November 23, 1980 Campania-Basilicata event (X MSK, Ms 6.9). The distribution of the earthquake environmental effects, in particular their distance from the known or supposed causative fault, has been investigated to obtain a more detailed and comprehensive picture of the macroseismic field, a key parameter in seismic hazard assessment and seismic zonation. KEY WORDS: historical seismicity, intensity, ground effects, earthquak

Ground effects and hydrological changes in the Southern Apennines (Italy) in response to the 23 July 1930 earthquake (<i>M_S</i>=6.7)

The 23 July 1930 earthquake (MS=6.7) in the Southern Apennines (Italy) was a catastrophic event that produced many effects such as surface faulting, fractures, landslides, settlements, hydrological changes, variations in chemical/physical activity related to the volcanic and/or thermal zones and also acoustic and optical phenomena. It is the first great earthquake of the twentieth century that was studied, thanks to the hydrological monitoring network of the Italian Hydrographic Survey (IHS) set up from 1925 to 1929. For this earthquake we analysed the initial IHS hydrometric and pluviometric data, looking for significant anomalies in springs, water wells and mountain streams. Hydrological data relative to rivers, springs and water wells indicate that some changes can be correlated with the earthquake: a post-seismic excess discharge in some streams, pre- and co-seismic decreases in stream flows and water levels in wells, pre- and post-seismic increases in discharges. The pre- and co-seismic stresses and the tectonic deformations were studied in order to find a possible model of interaction between stress state and hydrological variations. The anomalies found in this work can be considered "rebound anomalies", which are the most common precursor reported by many authors and related to increases in porosity and permeability caused by the fracturing that precedes an earthquake. An estimation of the total excess discharge (0.035 km3) caused by the MS=6.7 Irpinia earthquake is consistent with the excess discharge of about 0.01 km3 determined for the Mw=6.9 Loma Prieta earthquake

Risultati preliminari della campagna oceanografica CAFE_07 – Leg 3 nei Golfi di Napoli e Pozzuoli, Mar Tirreno Orientale

Vengono presentati i risultati preliminari della campagna oceanografica CAFE_07 - Leg 3, svoltasi nei Golfi di Napoli e Pozzuoli, nel Gennaio 2008, a bordo della Nave Oceanografica (N/O) URANIA del CNR. Lo scopo della campagna è stato l’acquisizione di profili sismici multicanale di elevata risoluzione dedicati allo studio stratigrafico-strutturale degli apparati vulcanici affioranti e sepolti nell’offshore Napoletano, ed il rilievo batimetrico di dettaglio dell’area sommersa. I dati raccolti sono consistiti in circa 800 km di profili sismici a riflessione multicanale di alta risoluzione, con acquisizione sismica simultanea da due sorgenti GI-gun operanti con potenza e frequenze differenti,mediante due cavi idrofonici. Durante la navigazione sono stati anche acquisiti profili sismici a riflessione monocanale di altissima risoluzione (sub-bottom CHIRP) e dati batimetrici mediante ecoscandaglio multifascio (multibeam). Il grid di acquisizione sismica multicanale è consistito in alcuni profili lunghi attraverso il Golfo di Napoli e da una fitta griglia di profili più corti, con interasse di circa 150 m, allo scopo di ottenere una copertura sismica quasi 3-D del Golfo di Pozzuoli. Questo set di dati costituisce una parte delle indagini di dettaglio richieste per la stesura di una proposta di perforazione del settore sommerso dei Campi Flegrei da sottomettere all’Integrated Ocean Drilling Program (IODP) ed è di supporto alla realizzazione di un progetto di perforazione profonda dei Campi Flegrei presentato all’International Continental Drilling Program (ICDP). We present the preliminary results of the oceanographic cruise CAFE_07 – Leg 3, conducted in the Napoli and Pozzuoli Bays in January 2008, on board of the Research Vessel (R/V) URANIA of the CNR. The aim of the cruise was the acquisition of high resolution multi-channel seismic profiles to understand the stratigraphic-structural setting of the Pozzuoli Bay area, with specific reference to the major offshore volcanic features, as well as the acquisition of bathymetric data on the seafloor morphology of the Bay. About 800 km of seismic profiles were acquired simultaneously by two acquisition systems, each characterized by different seismic source and streamer configuration, operating at different frequency ranges. Moreover shallow high resolution seismic reflection profiles (sub-bottom CHIRP) and multibeam echo-sounder bathymetry data have been recorded. The seismic grid consisted in a number of assistant profiles acquired over the Bay of Naples, along with a dense network of profiles with average distance of about 150 m between navigation routes, in order to obtain a quasi 3-D seismic coverage of the Pozzuoli Bay. This data set represents a part of the requirements for on-site detailed investigations (“site survey”) that are necessary for the development of an Integrated Ocean Drilling Program (IODP) proposal dedicated to the offshore drilling of the Campi Flegrei and is a relevant complement in the site survey of an ongoing project that has been submitted to the International Continental Drilling Program (ICDP)

Cataloguing earthquake environmental effects in Italy : Analyses of some strong earthquakes

Cataloguing earthquake environmental effects in Italy : Analyses of some strong earthquake

Plasmopara viticola infection affects mineral elements allocation and distribution in Vitis vinifera leaves

Plasmopara viticola is one of the most important pathogens infecting Vitis vinifera plants. The interactions among P. viticola and both susceptible and resistant grapevine plants have been extensively characterised, at transcriptomic, proteomic and metabolomic levels. However, the involvement of plants ionome in the response against the pathogen has been completely neglected so far. Therefore, this study was aimed at investigating the possible role of leaf ionomic modulation during compatible and incompatible interactions between P. viticola and grapevine plants. In susceptible cultivars, a dramatic redistribution of mineral elements has been observed, thus uncovering a possible role for mineral nutrients in the response against pathogens. On the contrary, the resistant cultivars did not present substantial rearrangement of mineral elements at leaf level, except for manganese (Mn) and iron (Fe). This might demonstrate that, resistant cultivars, albeit expressing the resistance gene, still exploit a pathogen response mechanism based on the local increase in the concentration of microelements, which are involved in the synthesis of secondary metabolites and reactive oxygen species. Moreover, these data also highlight the link between the mineral nutrition and plants\u2019 response to pathogens, further stressing that appropriate fertilization strategies can be fundamental for the expression of response mechanisms against pathogens