Search results for " earthquake"
showing 10 items of 81 documents
Coseismic extension recorded within the damage zone of the Vado di Ferruccio Thrust Fault, Central Apennines, Italy
2018
Recent high resolution hypocentral localisation along active fault systems in the Central Apennines illuminates the activation of seismogenic volumes dipping at low angle (<30°) in extensional settings overprinting contractional deformations affecting the continental crust of the Adria microplate. Individuation of the geological structures and of the fault processes associated with these seismic patterns will contribute to the interpretation of seismic sequence evolution, and seismic hazard studies.Here we report field and microstructural evidence of seismogenic extensional faults localized within pre-existing thrust fault zones. The Vado di Ferruccio Thrust Fault (VFTF) is a narrow …
An algorithm for earthquakes clustering based on maximum likelihood
2007
In this paper we propose a clustering technique set up to separate and find out the two main components of seismicity: the background seismicity and the triggered one. We suppose that a seismic catalogue is the realization of a non homogeneous space-time Poisson clustered process, with a different parametrization for the intensity function of the Poisson-type component and of the clustered (triggered) component. The method here proposed assigns each earthquake to the cluster of earthquakes, or to the set of independent events, according to the increment to the likelihood function, computed using the conditional intensity function estimated by maximum likelihood methods and iteratively chang…
Flexible space-time process for seismic data
2009
Point processes are well studied objects in probability theory and a powerful tool in statistics for modelling and analyzing the distribution of real phenomena, such as the seismic one. Point processes can be specified mathematically in several ways, for instance, by considering the joint distributions of the counts of points in arbitrary sets or defining a complete intensity function. The conditional intensity function is a function of the point history and it is itself a stochastic process depending on the past up to time t. In this paper some techniques to estimate the intensity function of space-time point processes are developed, by following semi-parametric approaches and diagnostic m…
The relationship between eruptive activity, flank collapse, and sea level at volcanic islands: A long-term (>1 Ma) record offshore Montserrat, Les…
2016
Hole U1395B, drilled southeast of Montserrat during Integrated Ocean Drilling Program Expedition 340, provides a long (>1 Ma) and detailed record of eruptive and mass-wasting events (>130 discrete events). This record can be used to explore the temporal evolution in volcanic activity and landslides at an arc volcano. Analysis of tephra fall and volcaniclastic turbidite deposits in the drill cores reveals three heightened periods of volcanic activity on the island of Montserrat (∼930 to ∼900 ka, ∼810 to ∼760 ka, and ∼190 to ∼120 ka) that coincide with periods of increased volcano instability and mass-wasting. The youngest of these periods marks the peak in activity at the Soufriere Hills vol…
Recognition of earthquake-induced damage in the Abakainon necropolis (NE Sicily): results from geo-morphological, geophysical and numerical analyses
2017
Seismotectonic activity and slope instability are a permanent threat in the archaeological site of Abakainon and in the nearby village of Tripi in NE Sicily. In recent times, signs of an ancient earthquake have been identified in the necropolis of Abakainon which dating was ascertained to the first century AD earthquake. The site is located on a slope of Peloritani Mts. along the Tindari Fault Line and contains evidence for earthquake-induced landslide, including fallen columns and blocks, horizontal shift and counter slope tilting of the tomb basements. In this paper, we used an integrated geomorphological and geophysical analysis to constrain the landslide. The research was directed to th…
Validation of an ontology of risk and disaster through a case study of the 1923 Great Kanto Earthquake
2009
International audience; This paper seeks to validate a factual ontologyderived from an ontology of the domain of risk and catastrophe (Provitolo, Müller, Dubos-Paillard, 2009). The factual ontology is that part describing the structure and dynamics of the system, that is, the representation of an event and of on what it has a bearing. The objective is to show that the ontology is able to account for and allow comparison between complex stories (because of the diversity of event types and of their multi-scale description). The event used as the basis for validation of the ontology is the Great Kanto Earthquake of 1923. The account is that of P. Hadfield (1991) that provides a detailed descri…
Predicting Earthquake-Induced Landslides by Using a Stochastic Modeling Approach: A Case Study of the 2001 El Salvador Coseismic Landslides
2023
In January and February 2001, El Salvador was hit by two strong earthquakes that triggered thousands of landslides, causing 1259 fatalities and extensive damage. The analysis of aerial and SPOT-4 satellite images allowed us to map 6491 coseismic landslides, mainly debris slides and flows that occurred in volcanic epiclastites and pyroclastites. Four different multivariate adaptive regression splines (MARS) models were produced using different predictors and landslide inventories which contain slope failures triggered by an extreme rainfall event in 2009 and those induced by the earthquakes of 2001. In a predictive analysis, three validation scenarios were employed: the first and the second …
Volcanic risk and the role of the media. A case study in the Etna area
2019
On December 24, 2018, the Etna volcano has recorded a significant eruption. Linked to this phenomenon, after a seismic swarm of 72 shocks, a 4.8-magnitude earthquake struck a large area North of Catania city, on the Eastern coast of Sicily. Six villages reported 28 injured people and damages to the building. According to seismologists the earthquake had an unusual level of magnitude. Yet, despite the real danger of this event, many people who live around the volcano, in one of the most densely populated areas of Sicily, perceived these facts in an ambivalent way. Indeed, their lives continued as before even in awareness of the natural hazard, while several media presented the situation as r…
Community detection of seismic point processes
2022
In this paper, we combine robin and Local Indicators of Spatio-Temporal Association (LISTA) functions. robin is an R package to assess the robustness of the community structure of a network found by one or more methods to give indications about their reliability. We use it to propose a classification algorithm of events in a spatio-temporal point pattern, by means of the local second-order characteristics and the community detection procedure in network analysis. We demonstrate the proposed procedure on a real data analysis on seismic data.
L'utilizzo del ferro a Palermo dopo il terremoto del 1726
2016
La ricerca, basata essenzialmente sullo studio di una consistente mole di documenti emersi attraverso nuove indagini archivistiche, mira a indagare gli aspetti tecnici legati agli interventi sul patrimonio architettonico di Palermo successivi al terremoto del 1726, approfondendo il ruolo degli architetti e dei maestri coinvolti nel processo di ricostruzione delle fabbriche colpite e ponendo particolare attenzione alle tecnologie messe in atto facenti ricorso all’uso ferro, indagate attraverso lo studio di alcuni casi esemplificativi. Questo materiale, infatti, trovò in questa occasione diverse applicazioni. L’intervento più frequente fu relativo all’inserimento di catene in ferro in corrisp…