scholarly journals Recent seismic activity at Cephalonia (Greece): a study through candidate electromagnetic precursors in terms of non-linear dynamics

2016 ◽  
Vol 23 (4) ◽  
pp. 223-240 ◽  
Author(s):  
Stelios M. Potirakis ◽  
Yiannis Contoyiannis ◽  
Nikolaos S. Melis ◽  
John Kopanas ◽  
George Antonopoulos ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Linear Processes ◽  
Hazard Zoning ◽  
Natural Time ◽  
Non Linear ◽  
Electromagnetic Emissions ◽  
Critical Characteristics ◽  
Recent Earthquakes ◽  
Neighbouring Island ◽  
Electromagnetic Precursors

Abstract. The preparation process of two recent earthquakes (EQs) that occurred in Cephalonia (Kefalonia), Greece, ((38.22° N, 20.53° E), 26 January 2014, Mw = 6.0, depth  ∼  20 km) and ((38.25° N, 20.39° E), 3 February 2014, Mw = 5.9, depth  ∼  10 km), respectively, is studied in terms of the critical dynamics revealed in observables of the involved non-linear processes. Specifically, we show, by means of the method of critical fluctuations (MCF), that signatures of critical, as well as tricritical, dynamics were embedded in the fracture-induced electromagnetic emissions (EMEs) recorded by two stations in locations near the epicentres of these two EQs. It is worth noting that both the MHz EMEs recorded by the telemetric stations on the island of Cephalonia and the neighbouring island of Zante (Zakynthos) reached a simultaneously critical condition a few days before the occurrence of each earthquake. The critical characteristics embedded in the EME signals were further verified using the natural time (NT) method. Moreover, we show, in terms of the NT method, that the foreshock seismic activity also presented critical characteristics before each event. Importantly, the revealed critical process seems to be focused on the area corresponding to the western Cephalonia zone, following the seismotectonic and hazard zoning of the Ionian Islands area near Cephalonia.

scholarly journals Recent seismic activity at Cephalonia island (Greece): a study through candidate electromagnetic precursors in terms of nonlinear dynamics

2015 ◽  
Vol 2 (6) ◽  
pp. 1587-1629 ◽  
Author(s):  
S. M. Potirakis ◽  
Y. Contoyiannis ◽  
N. S. Melis ◽  
J. Kopanas ◽  
G. Antonopoulos ◽  
...  
Keyword(s):  
Seismic Activity ◽  
The West ◽  
Linear Processes ◽  
Hazard Zoning ◽  
Natural Time ◽  
Electromagnetic Emissions ◽  
Critical Characteristics ◽  
Recent Earthquakes ◽  
Electromagnetic Precursors ◽  
Critical Process

Abstract. The preparation process of two recent earthquakes (EQs) occurred in Cephalonia (Kefalonia) island, Greece, (38.22° N, 20.53° E), 26 January 2014, Mw =6.0, depth =21 km, and (38.25° N, 20.39° E), 3 February 2014, Mw =5.9, depth =10 km, respectively, is studied in terms of the critical dynamics revealed in observables of the involved non-linear processes. Specifically, we show, by means of the method of critical fluctuations (MCF), that signatures of critical, as well as tricritical, dynamics were embedded in the fracture-induced electromagnetic emissions (EME) recorded by two stations in locations near the epicenters of these two EQs. It is worth noting that both, the MHz EME recorded by the telemetric stations on the island of Cephalonia and the neighboring island of Zante (Zakynthos), reached simultaneously critical condition a few days before the occurrence of each earthquake. The critical characteristics embedded in the EME signals were further verified using the natural time (NT) method. Moreover, we show, in terms of the NT method, that the foreshock seismic activity also presented critical characteristics before each one of these events. Importantly, the revealed critical process seems to be focused on the area corresponding to the west Cephalonia zone, following the seismotectonic and hazard zoning of the Ionian Islands area near Cephalonia.

The structure of non-linear processes

Tellus ◽  
1973 ◽  
Vol 25 (6) ◽  
pp. 536-544 ◽  
Author(s):  
A. Quinet
Keyword(s):  
Linear Processes ◽  
Non Linear

scholarly journals Sustainable Development Goal Drivers in Food Systems

2021 ◽  
Vol 5 ◽  
Author(s):  
Sebastian Kretschmer ◽  
Johannes Kahl
Keyword(s):  
Sustainable Development ◽  
Food Systems ◽  
Sustainable Development Goals ◽  
Food System ◽  
Driving Forces ◽  
Linear Processes ◽  
Non Linear ◽  
Development Goals ◽  
Diagnostic Framework ◽  
Primary Predictor

Interacting driving forces in food systems, resulting in cumulative driver effects and synergies, induce non-linear processes in multiple directions. This paper critically reviews the discourse on driving forces in food systems and argues that mindset is the primary predictor for food system outcomes. In the epoch of sustainable development goals (SDGs) and the Anthropocene, mindset matters more than ever. Transformative narratives are beginning to transcend the dominant social paradigm, which is still driving the food system's overall trajectory. The psychosocial portrayal of the systemic mindset found in organic food systems presented in this paper “flips the script” and hypothesizes that worldview and paradigm have the most causal linkages with unsustainable driver synergies and reversely the biggest leverage on the mitigation thereof. Borrowing from ecological economics discourses, the paper sharpens the driver definition by applying the DPSIR analytical tool as a modified diagnostic framework and modeling approach for food systems. This research sheds new light on the nature of drivers of change, which are often portrayed as almighty and inevitable trends shaping food systems. Instead, it is proposed that drivers emerge from the actors' mindset, affecting food system behavior in a non-linear way. Mindset drives reinforcing feedback loops, resulting in vicious and virtuous cycles. These driver motives manifest in subsystems and continue to drive their interaction across food system elements. Mindset acts as an encapsulated input of food systems, all the while responding to feedback and releasing new drivers. A transformation framework along leverage points of the food system is presented that features the concept of SDG drivers.

Reducing Seismic out of Plane Vulnerability of Masonry Church Façades through Optimization of Capacity Spectrum by Tie Rods

2019 ◽  
Vol 817 ◽  
pp. 325-333
Author(s):  
Simonetta Baraccani ◽  
Giorgio Dan ◽  
Angelo Di Tommaso ◽  
Tomaso Trombetti
Keyword(s):  
Masonry Walls ◽  
Collapse Mechanisms ◽  
Capacity Spectrum ◽  
Construction Techniques ◽  
Non Linear ◽  
Out Of Plane ◽  
Recent Earthquakes ◽  
Discrete Element Methods ◽  
Tie Rods ◽  
The Church

The analyses of the structural damages detected on the Italian churches after the recent earthquakes (Emilia 2012, Umbria-Marche 2016) highlighted the high vulnerability to the overturning of the façades. The façades collapse mechanisms are strongly dependent on the connection details between orthogonal masonry walls, the windows, the construction techniques and the possible restraining horizontal elements, such as tie-beams, bi-lateral connected roof, etc. Several studies focus on the evaluation of vulnerability of the church façades using different approaches, from global analyses (FEM and /or Discrete Element Methods) of the entire building, to local analyses (linear and non-linear kinematic approaches). The aims of the present paper is to use the method based on capacity spectra to evaluate the vulnerability of the church facades and the optimization of specific devices as tie-rods to improve their seismic behavior. The non-linear approach is now accepted by several standards regarding the evaluation of risks of collapse mechanisms for masonry walls of the facades. Appropriate devices have been considered in order to calibrate the capacity curve and to optimize the interventions. The out of plane rotation of blocks can be modified with various elasto-perfect-plastic tendons with appropriate retentions (while composite materials could be used to preserve integrity of blocks). The tendons can be allocated in proper location and the length of each calibrated to best determine their stiffness. This procedure have been here applied to the study of the façade of Aula Magna S. Lucia of the Bologna University, considering also the problem of the interaction with the structure of the roof.

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