Search results for " earthquake"
showing 10 items of 81 documents
Generation of Earth's early continents from a relatively cool Archean mantle
2019
This research has been supported by DFG grant, SPP 1833 Building a Habitable Earth and MAGMA Consolidator Grant (ERC project #71143). Several lines of evidence suggest that the Archean (4.0 2.5 Ga) mantle was hotter than today's potential temperature (TP) of 1350 ° C. However, the magnitude of such difference is poorly constrained, with TP estimation spanning from 1500 ° C to 1600 ° C during the Meso‐Archean (3.2‐2.8 Ga). Such differences have major implications for the interpreted mechanisms of continental crust generation on the early Earth, as their efficacy is highly sensitive to the TP. Here, we integrate petrological modeling with thermomechanical simulations to understand the dynami…
Gibellina City of Art
2018
The earthquake that hit Western Sicily in 1968 destroyed, among others, the town of Gibellina. Back then, the town was abandoned and a new city was built ex novo at a distance of eighteen kilometres from the original site. The ex novo foundation of a new city requires the interaction of two fundamental components: one characterised by a physical-formal nature, related to urban layout and architectural characterisations, and the other related to socio-cultural issues concerning the relationships between citizens and their city. If the rst component might be dealt with by means of theories and techniques from architectural and urban disciplines, how is it possible to deal with the even more i…
A new large scale laboratory: The LEDA research centre (Laboratory of Earthquake engineering and Dynamic Analysis)
2017
Recently, the field of earthquake engineering experienced substantial enhancements due to numerous results of experimental and theoretical researches. Modern technical codes recognized the last advances in this field and provided new solutions for the structural assessment and design of buildings. However, the need for large scale testing is still taking several open questions, especially for the design of civil infrastructures, and experimental activity on full scale specimens has become necessary. This paper presents the main testing facilities of a new research centre, namely the Laboratory of Earthquake engineering and Dynamic Analysis (LEDA) of the University of Enna “Kore”. In particu…
Evaluating the performance of a new picking algorithm based on the variance piecewise constant models
2021
In this paper, a new picking algorithm for the automatic seismogram onset time determination is tested on a dataset of simulated waveforms. We aim at capturing the variations in the performance due to some characteristics of both the seismic event and its detection, which in turn affect some characteristics of the waveforms. We therefore simulate seismic events with different magnitude, and assumed to be detected with different distances from the nearest seismic station. Our tests permit to highlight the scenarios most suitable for our algorithm.
Spatio-temporal log-Gaussian Cox processes on earthquake events
2016
This work presents an application of spatio-temporal log-Gaussian Cox processes for the description of earthquake events. To explain the overall spatial trend, spatial geological information in the study area such as faults and volcanoes are introduced in the model. Moreover, an anisotropic specification of the covariance matrix of the Gaussian process is used to improve the explanation of the phenomenon. We apply and compare different models to explain the seismic events occurred in Alaska over the last decades.
Probabilistic Forecast for Northern New Zealand Seismic Process Based on a Forward Predictive Kernel Estimator
2011
In seismology predictive properties of the estimated intensity function are often pursued. For this purpose, we propose an estimation procedure in time, longitude, latitude and depth domains, based on the subsequent increments of likelihood obtained adding an observation one at a time. On the basis of this estimation approach a forecast of earthquakes of a given area of Northern New Zealand is provided, assuming that future earthquakes activity may be based on the smoothing of past earthquakes.
TERREMOTO E RICOSTRUZIONE: MESSINA 1908, VERSO UNA PROGETTAZIONE “CONSAPEVOLE” : La teoria della maggiore resistenza delle strutture “circolari” e il…
2019
TERREMOTO E RICOSTRUZIONE: MESSINA 1908, VERSO UNA PROGETTAZIONE “CONSAPEVOLE” La teoria della maggiore resistenza delle strutture “circolari” e il contributo della pubblicistica al dibattito sulla costruzione antisismica. Le storie raccontate in questo volume esaminano congiuntamente il duplice sguardo della ricerca sulla progettazione orientata in senso antisismico e sviluppata nell’ambito del dibattito nato a Messina dopo il terremoto del 1908. Se ampie si rivelano le testimonianze di forme di progettazioni “consapevoli”, cioè di accorgimenti che integrano il problema sismico all’interno di convenzioni costruttive di durata secolare, durante le fasi che hanno preceduto le molteplici rico…
Seismic response of braced frames with and without friction dampers
1995
Abstract The dynamic response of friction damped bracing systems and ordinary cross-bracing systems inserted into surrounding frames without lateral stiffness is analysed in order to compare the typical behaviour of the two different bracing systems. The cyclic force-displacement relationship in the two cases is accurately modelled on the basis of experimental and related numerical models which are available in the literature, and the structural dimensionless parameters defining the shapes of the cycles are stressed. Systems having the same average period of vibration in the elastic phase of the response are assumed to be comparable with one another, which leads to a relationship linking th…
The use of wood with an anti-seismic function in the architecture of palermo during the 18th century
2016
The study analyzes the interventions in the historical buildings after the earthquakes that struck Palermo in 1726 and 1751, with a particular attention to the anti-seismic reinforcements. The research, based primarily on archival documents, focuses on a series of interventions in the architectural heritage, in which the use of wood for structural elements, was able to guarantee for an “antiseismic” reconstruction. Although wood was not commonly used as other materials (iron, for instance) in the post-earthquake reconstruction process of Palermo it was certified its use as an anti-seismic system in the reinforcements of the damaged buildings. It is documented, for instance, the insertion of…
The Bell-Tower Facade: An Aseismic Device in Sicily Between the 12th and 18th Centuries
2014
Imposing tower facades with belfries in the last order were built in Sicily Italy, from the Middle Ages to the late Baroque period. Until the 16th century, this model, which was inspired by northern European examples, also had a parallelepiped forepart leaning against the facade, working as containment for the pressure imparted by the inner longitudinal arches on the front, and amplified in case of earthquakes. The lacking static efficiency of these early structures is demonstrated by collapses during the strong earthquakes that hit the island in the modern age. Despite numerous cases of destruction, the memory of some prototypes survived in Sicilian constructive memory through the elaborat…