Filippos Vallianatos

National and Kapodistrian University of Athens | uoa · Department of Geophysics and Geothermy

Seismic swarms are characterized by intense seismic activity strongly clustered in time and space and without the occurrence of a major event that can be considered as the mainshock. Such intense seismic activity is most commonly associated with external aseismic factors, as pore-fluid pressure diffusion, aseismic creep, or magmatic intrusion that...

On 27 September 2021, a significant M w =6.0 earthquake struck near Arkalochori village in central Crete, Greece, about~25 km south-southeast of Heraklion city. Remarkably, an extensive seismic swarm lasting nearly four months preceded the mainshock, activating structures near its hypocenter. In this work, we investigate the foreshock swarm by leve...

of magnitude Mw 6.1, Mw 6.0, and Mw 6.6 respectively using the complexity theory and the non-extensive statistical physics (NESP). The scaling properties that have been observed in the three aftershock sequences of the recent strong earthquakes that took place in the region of Ionian islands are presented. To analyze the evolution of three aftersho...

of magnitude Mw 6.1, Mw 6.0, and Mw 6.6 respectively using the complexity theory and the non-extensive statistical physics (NESP). The scaling properties that have been observed in the three aftershock sequences of the recent strong earthquakes that took place in the region of Ionian islands are presented. To analyze the evolution of three aftersho...

The spatiotemporal evolution of earthquakes induced by fluid injections into the subsurface can be erratic owing to the complexity of the physical process. To effectively mitigate the associated hazard and to draft appropriate regulatory strategies, a detailed understanding of how induced seismicity may evolve is needed. In this work, we build on t...

Supplementary Information for the paper "Are foreshocks fore-shocks?"

Plain Language Summary Large earthquakes can be preceded by a wide range of different seismic anomalies. Among these, seismicity has been reported to increase both in magnitude and frequency, but, on the other hand, it can also undergo a short period of reduced intensity before major events. The first pattern corresponds to the occurrence of foresh...

The largest earthquakes control large part of the energy budget of seismogenic structures which is progressively accumulated in the adjoining volumes meanwhile the fault system is kept locked. As wide-scale destabilization is approaching, seismic activity may increase, which can produce further instability leading to the mainshock. Foreshocks are t...

Significant seismic activity has been witnessed in the area of Ridgecrest (Southern California) over the past 40 years, with the largest being the Mw 5.8 event on 20 September 1995. In July 2019, a strong earthquake of Mw 7.1, preceded by a Mw 6.4 foreshock, impacted Ridgecrest. The mainshock triggered thousands of aftershocks that were thoroughly...

In this work Ground Penetrating Radar (GPR) results achieved in the archaeological site of Ancient Falasarna Harbour in Western Crete (Greece), are presented. The survey has been performed in a site only slightly explored up to now and where has been covered by the tsunami deposits created by the AD 365 earthquake event with magnitude 8.3 located o...

Hydraulic stimulation of a geothermal reservoir aims to increase the permeability of the rock formations by creating/enhancing a fracture network, to take advantage of the geothermal energy hosted by deep hot formations. A common side effect of the fracturing process is the small-in-magnitude but abundant induced seismicity. In this work, we study...

This study delves into the southern Aegean regionwhere the subduction of the oceanic Mediterranean lithosphere under the Aegean continental one takes place. This region is considered one of the most active ones in the eastern Mediterranean Sea due to intense tectonic movements in the Late Quaternary. More than 1200 manually revised events from 2018...

Crete is located in the Southern Aegean, in the southernmost part of the Hellenic Trench. Given the large number of earthquakes in the region generated by the convergence of the Eurasian and African tectonic plates, the research area is critical. More than 7000 manually revised events from 2018 to 2023 were used in this work to construct local 1D v...

This study delves into the Southern Aegean region where the subduction of the oceanic Mediterranean lithosphere under the Aegean continental one takes place. This region is considered one of the most active ones in the Eastern Mediterranean Sea due to intense tectonic movements in the Late Quaternary. More than 1200 manually revised events from 201...

Seismic swarms frequently exhibit spatial migration of event hypocenters with time attributed to external aseismic stresses, such as pore-fluid pressure diffusion, aseismic creep, or magmatic intrusion, that may act as the driving mechanism. Earthquake diffusion, observed in such cases, can be highly anisotropic, occurring preferentially along frac...

An earthquake swarm occurred during 2020-2021 at the Perachora peninsula, situated at the eastern part of the Gulf of Corinth (Greece), one of the most seismically active areas in Europe. In this work, we analyzed the swarm using a high-resolution earthquake catalog and advanced processing techniques. We employed both single-station and multi-chann...

Waiting times distributions between successive earthquakes have extensively been studied to provide insights into the physical mechanism of seismogenesis and to effectively assess seismic hazard. While in tectonic seismicity the waiting times distribution is well-defined as the superposition of Omori-like aftershock sequences on correlated and/or r...

Aftershocks of earthquakes can destroy many urban infrastructures and exacerbate the damage already inflicted upon weak structures. Therefore, it is important to have a method to forecast the probability of occurrence of stronger earthquakes in order to mitigate their effects. In this work, we applied the NESTORE machine learning approach to Greek...

The Eastern Gulf of Corinth (EGoC) is one of the most seismically active areas in Greece. It is monitored by local and regional seismic stations of the Hellenic Unified Seismic Network (HUSN). In 2020, a high-yield seismic sequence, lasting over five months, occurred at the Perachora peninsula. This provided a unique opportunity to investigate the...

Greece exhibits the highest seismic activity in Europe, manifested in intense seismicity with large magnitude events and frequent earthquake swarms. In the present work, we analyzed the spatiotemporal properties of recent earthquake swarms that occurred in the broader area of Greece using the Non-Extensive Statistical Physics (NESP) framework, whic...

The Corinth Rift, in Central Greece, is one of the most seismically active areas in Europe. In the eastern part of the Gulf of Corinth, which has been the site of numerous large and destructive earthquakes in both historic and modern times, a pronounced earthquake swarm occurred in 2020-2021 at the Perachora peninsula. Herein, we present an in-dept...

Greece is one of Europe’s most seismically active areas. Seismic activity in Greece has been characterized by a series of strong earthquakes with magnitudes up to Mw = 7.0 over the last five years. In this article we focus on these strong events, namely the Mw6.0 Arkalochori (27 September 2021), the Mw6.3 Elassona (3 March 2021), the Mw7.0 Samos (3...

Crete is located in the Southern Aegean, in the southernmost part of the Hellenic Trench. Given the elevated numbers of seismicity in the region generated by the convergence of the Eurasian and African tectonic plates, the research area is critical. More than 1400 manually revised events from 2018 to 2022 have been used in this work to construct bo...

L’étude des séismes est un champ multidisciplinaire où se rencontrent, entre autres, la géodynamique, les mathématiques, la physique et l’ingénierie, mais également le hasard.Méthodes et modèles statistiques pour la sismogenèse offre un ensemble riche et varié de méthodes permettant l’étude statistique et la prévision des séismes. Il détaille les m...

Large subduction-zone earthquakes generate long-lasting and wide-spread aftershock sequences. The physical and statistical patterns of these aftershock sequences are of considerable importance for better understanding earthquake dynamics and for seismic hazard assessments and earthquake risk mitigation. In this work, we analyzed the statistical pro...

The ML 5.8 earthquake that hit the island of Crete on 27 September 2021 is analysed with InSAR (Interferometry from Synthetic Aperture Radar) and GNSS (Global Navigation Satellite System) data. The purpose of this work is to create a model with sufficient detail for the geophysical processes that take place in several kilometres below the earth’s s...

Research Highlights The cumulative distribution with respect to earthquake magnitude was examined for 44 aftershock sequences of M≥7 earthquakes in subduction zones worldwide. Based on the fragment-asperity model, the entropic index qM was estimated, with a range of 0.82 1.80.

This work presents an analysis of the earthquake frequency-magnitudes distribution for the aftershock sequences of recent strong earthquakes in Greece, with magnitudes that reach up to 7.0.

The occurrence of microseismicity is often overlooked as non significant, yet it can reveal important aspects of the evolution of seismicity at a region and the geological structures that accommodate this seismicity (Ross et al., 2019; Helmstetter et al., 2005; Marsan D., 2005; Helmstetter, 2003). Permanent seismic monitoring networks do not allow...

The 27 September 2021 damaging mainshock (Mw6.0) with a seismic moment Mo of 1.14 × 10 18 N·m is the first known strong earthquake that ruptured the Central Crete (Greece) close to Arkalochori village, during the last hundred years. The main shock was preceded by foreshock activity lasting for about four months. In this work, we present the 4484 3E...

Induced seismicity represents a significant obstacle to the development of various industrial projects associated with energy production from the subsurface. To effectively mitigate the associated seismic hazard, a better understanding of the physical mechanisms of induced seismicity is required. Within this context, the efficient modelling of the...

The pandemic of COVID-19 and the global policy implemented to attenuate the spread of the virus, provided a unique opportunity to study the footprint of the resulting social impact of COVID-19 pandemic on seismic data. In this study, a non-extensive statistical physics approach is examined for anthropogenic high-frequency seismic noise in view of C...

Algorithms that deal with the automatic P-and S-onset time identification problem are a topic of ongoing research. Modern dense seismic networks used for earthquake location, focal mechanism determination, seismic tomography investigations, source studies, early warning, etc., demand accurate automatic arrival time estimations of compressional and...

In this work, we study the January 1, 2020 – June 8, 2021, earthquake activity in the East Corinth Rift (central Greece), one of the most seismically active areas in Europe. During this period an intense earthquake sequence occurred in the Perachora peninsula, presenting the characteristics of swarm activity. We present a relocated earthquake catal...

The 27 September 2021 damaging mainshock (Mw6.0) close to Arkalochori village is the strongest earthquake that was recorded during the instrumental period of seismicity in Central Crete (Greece). The mainshock was preceded by a significant number of foreshocks that lasted nearly four months. Maximum ground subsidence of about 18 cm was estimated fr...

Nowadays, there has been a growing interest in understanding earthquake forerunners, i.e., anomalous variations that are possibly associated with the complex process of earthquake evolution. In this context, the Robust Satellite Technique was coupled with 10 years (2012–2021) of daily night-time MODIS-Land Surface Temperature remote sensing data to...

Among the different parameters, the fluctuations of Earth's thermally emitted radiation, as measured by sensors on board of satellite systems operating in the Thermal Infra-Red (TIR) spectral range and Earth's surface deformation as recorded by satellite radar interferometry, have been proposed since long time as potential earthquake precursors. Ne...

In 2020, a pronounced earthquake sequence occurred at the Perachora peninsula, at the eastern edge of the active continental Corinth Rift (Greece). The sequence evolved as a swarm over the course of four months, with the largest magnitude event (M w =3.7) occurring approximately 2 months after its initiation. The sequence was widely felt by the loc...

Due to the significant increase in the availability of new data in recent years, as a result of the expansion of available seismic stations, laboratory experiments, and the availability of increasingly reliable synthetic catalogs, considerable progress has been made in understanding the spatiotemporal properties of earthquakes [...]

On March 3, 2021, a strong shallow earthquake of magnitude Mw 6.3 struck Northern Thessaly, an area that lies in one of the most active fault zones of mainland Greece. The mainshock generated numerous aftershocks, with some of large magnitude reaching up to Mw 6.0. In this work, we study the scaling properties and the physical mechanisms of aftersh...

On 27 September 2021, a shallow earthquake with focal depth of 10 km and moment magnitude Mw6.0 occurred onshore in central Crete (Greece). The evolution of possible preseismic patterns in the area of central Crete before the Mw6.0 event was investigated by applying the method of multiresolution wavelet analysis (MRWA), along with that of natural t...

One of the main goals of an Earthquake Early Warning System (EEWS) is to estimate the expected peak ground motion of the destructive S-waves using the first few seconds of P-waves, thus becoming an operational tool for real-time seismic risk management in a short timescale. EEWSs are based on the use of scaling relations between parameters measured...

The Western Gulf of Corinth (WGoC), Central Greece, is one of the fastest expanding continental rifts in the world and a closely monitored site of high geophysical interest. In this work, we employ data from the Corinth Rift Laboratory network and the Hellenic Unified Seismological Network to investigate the anisotropic properties of the upper crus...

The presence and circulation of pressurized fluids in the Earth’s crust can induce earthquakes. Such phenomena, related either to natural processes or to man-made activities, have recently drawn intense scientific attention due to the increased number of the globally reported events. A characteristic of fluid-induced seismicity is its spatial migra...

The Western Gulf of Corinth (WGoC), Central Greece, is one of the fastest expanding continental rifts in the world and a closely monitored site of high geophysical interest. In this work, we employ data from the Corinth Rift Laboratory network and the Hellenic Unified Seismological Network to investigate the anisotropic properties of the upper crus...

The main goal of an Earthquake Early Warning System (EEWS) is to estimate the expected peak ground motion of the destructive S-waves using the first few seconds of P-waves, thus becoming an operational tool for real-time seismic risk management in a short timescale. EEWSs are based on the use of scaling relations between parameters measured on the...

On 3 March 2021, a strong, shallow earthquake of moment magnitude, Mw6.3, occurred in northern Thessaly (Central Greece). To investigate possible complex correlations in the evolution of seismicity in the broader area of Central Greece before the Mw6.3 event, we apply the methods of multiresolution wavelet analysis (MRWA) and natural time (NT) anal...

In recent years, there is a growing interest concerning the development of a multi-parametric system for earthquakes’ short term forecast identifying those parameters whose anomalous variations can be associated to the complex process of such events. In this context, the Robust Satellite Technique (RST) has been adopted herein with the aim to detec...

Earthquake diffusion and the migration behaviour of seismic clusters are commonly studied to provide insight on the spatiotemporal evolution of seismicity and the interplaying driving mechanisms. Using a high-resolution relocated catalogue, we study the variations of the earthquake diffusion rates in the Western Gulf of Corinth during 2013–2014, a...

The main goal of an Earthquake Early Warning System (EEWS) is to alert before the arrival of damaging waves using the first seismic arrival as a proxy, thus becoming an important operational tool for real-time seismic risk management on a short timescale. EEWSs are based on the use of scaling relations between parameters measured on the initial por...

The Western Gulf of Corinth (WGoC) exhibits significant seismicity patterns, combining intense microseismic background activity with both seismic swarms and short-lived aftershock sequences. Herein, we present a catalogue of ~9000 events, derived by manual analysis and double-difference relocation, for the seismicity of the WGoC during 2013–2014. T...

In the present work, a multiscale post-seismic relaxation mechanism, based on the existence of a distribution in relaxation time, is presented. Assuming an Arrhenius dependence of the relaxation time with uniform distributed activation energy in a mesoscopic scale, a generic logarithmic-type relaxation in a macroscopic scale results. The model was...

The statistical patterns occurring on the threshold of an earthquake, in the transition stage immediately before and after the rupture, still remain unclear. Investigating the dynamical features of surface deformation a few days before and after the earthquake co-seismic rupture are crucial to understand the mechanics of the earthquake process. In...

Fluid-injections under high pressures into deep "hot" rock formations are routinely performed during the development of Enhanced Geothermal Systems (EGS). Such fluid-injections, which aim to enhance the permeability in the targeted rock formation, can induce intense microseismicity and in some cases even larger magnitude earthquakes. A characterist...

Earthquake diffusion is frequently observed in the spatiotemporal evolution of seismic clusters and regional seismicity, a characteristic that is attributed to a triggering mechanism, such as fluid flow, aseismic creep and/or stress transfer effects. In this work, we study the earthquake diffusion properties in the Western Gulf of Corinth (central...

On October 30, 2020, a strong and shallow earthquake (Mw = 7.0) hit Samos, an island on the eastern edge of the Aegean Sea (Greece). The epicenter was located on the north offshore of the Greek island of Samos. The goal of our work is to provide a first analysis of the scaling properties observed in the aftershock sequence as reported until Decembe...

Strong motion sensor networks deployed in metropolitan areas are able to provide valuable information for civil protection Decision Support Systems (DSSs) aiming to mitigate seismic risk and earthquake social-economic impact. To this direction, such a network is installed and real-time operated in Chania (Crete Island, Greece), city located in the...

On October 30, 2020 a strong shallow earthquake of magnitude Mw=7.0 occurred on the Eastern edge of Aegean Sea. The epicenter was located on the North offshore of the Greek island of Samos. The aim of our work is to present a first analysis of the scaling properties observed in the aftershock sequence as reported until December 31, 2020, as numerou...

A correction to this paper has been published: https://doi.org/10.1007/s00024-021-02692-4

Earthquakes occur on complex and (multi)fractal fault networks that vary in size between millimeters (microcracks), to tens (major fault zones) and hundreds of kilometers (tectonic plate boundaries). This chapter provides a mini‐review on some of the collective properties of earthquake populations in the time domain. Based on these properties, it d...

The National Observatory of Athens data center for the European Integrated Data Archive (EIDA@NOA) is the national and regional node that supports International Federation of Digital Seismograph Networks and related webservices for seismic waveform data coming from the southeastern Mediterranean and the Balkans. At present, it serves data from eigh...

Many islands of the Aegean Sea show strong geothermal activity due to volcanism in the area. In this paper, Robust Satellite Techniques (RST) are used to isolate, from other known possible sources, those thermal anomalies possibly related to geothermal activity in the Miocene volcanic field of Lesvos Island (Northern Aegean). For this purpose, 12 y...

In the present work we apply the cBΩ thermodynamic model to study the diffusion of Si 13 in stishovite crystal at high pressure and in a wide temperature range. According to this model, the point defect activation Gibbs free energy is expressed as a function of the bulk properties of the material, i.e. g_act =cBΩ, where B is the isothermal bulk mod...

Until now proposed Operational Earthquakes Forecast (OEF) methods suffer of strong limitations in terms of their actual (too low absolute value of estimated probabilities) and general (forecast is substantially limited to earthquakes which are preceded by foreshocks) operational applicability [e.g. Wang and Rogers, 2014; Panza et al., 2014]. They b...

This paper may be considered as an additional approval of the way the tectonic activity affects the lower Ionosphere. The results of our investigation, on the occasion of the recent East Aegean tectonic activity, indicate that the High - Frequency limit, fo, of the ionospheric turbulence content, increases as the site and the time of the earthquake...

Fracturing processes within solid Earth materials are inherently a complex phenomenon so that the underlying physics that control fracture initiation and evolution still remain elusive. However, universal scaling relations seem to apply to the collective properties of fracturing phenomena. In this article we present a statistical physics approach t...

The unique physicochemical, electrical, mechanical, and thermal properties of micas make them suitable for a wide range of industrial applications, and thus, the interest for these kind of hydrous aluminosilicate minerals is still persistent, not only from a practical but also from a scientific point of view. In the present work, complex impedance...

The Polyphyto Dam, with a maximum water depth of 95 m and maximum water volume of ~ 1220 × 106 m3, is a medium-sized reservoir established on the Aliakmonas river (North Greece) in 1974. Although the broader area was considered as low seismic risk, a strong and damaging earthquake of magnitude (Mw) 6.6 occurred on May 13, 1995. In the present work,...

The present study focuses on the Western Gulf of Corinth (WGoC), which is one of the most seismically active sites in Europe and also the region where the Corinth Rift Laboratory (CRL) Near Fault Observatory (NFO) has been installed. The WGoC exhibits high extension rates and intense microseismicity, with frequent occurrence of clustered seismicity...

The last decades a lot of progress has been made in studying Earth and planetary Physics based on the science of complexity and the application of generalized formalisms of statistical physics and entropy. Towards this direction, investigation of the dynamical features of seismic waves is of fundamental importance since they could provide informati...

In this paper, we present the recent progress in the experimental studies of the electrical conductivity of dominant nominally anhydrous minerals in the upper mantle and mantle transition zone of Earth, namely, olivine, pyroxene, garnet, wadsleyite and ringwoodite. The main influence factors, such as temperature, pressure, water content, oxygen fug...

The drainage basins of Greece are analyzed in terms of hierarchy and discussed in view of Tsallis Entropy. This concept has been successfully used in a variety of complex systems, where fractality, memory and long-range interactions are dominant. The analysis indicates that the statistical distribution of drainage basins’ area in Greece, presents a...

Episodic earthquake activity associated with pore-fluid pressure diffusion in the crust can frequently be observed in intraplate regions, particularly related with past volcanism. Increased micro-seismicity has been observed during 2012-2014 in such an area, near the CO2-rich Florina basin (North Greece). Using a high-resolution relocated catalog f...

Soundless chemical demolition agents (SCDAs) have been used during the last decades in the demolition of boulders and concrete structures as well as in open-surface and sub-surface rock excavation, as an alternative to the use of explosives posing safety risks. However, the knowledge of the governing fracture mechanisms in brittle materials is rath...

Non-extensive statistical physics (NESP) provides the theoretical tool to investigate complex systems that appear in different length-scales and violate the classical Boltzmann–Gibbs statistics. In the present study, we apply the concept of NESP to analyze the Acoustic Emissions (AE) series recorded during uniaxial compression of brittle rocks, suc...

A number of 2D Electrical Resistivity Tomographies (ERT) was conducted in northwest and southwest Crete with the aim to model geotectonic features at selected urban sites. The study area is located within the central forearc of the Hellenic subduction zone. Thirteen ERT profiles were realized using the dipole-dipole electrode and/or the Wenner-Schl...

The link between hurricanes or typhoons and their generated ambient noise has recently become a frontier topic in the field of applied seismology. In the Mediterranean region, infrequent tropical-like cyclones, known as Medicanes or Mediterranean hurricanes, with similar characteristics with hurricanes appear, with the most recent storm occurred on...

Earthquake time series are widely used to characterize the main features of regional seismicity and to provide useful insights into earthquake dynamics. Properties such as intermittency and nonstationary clustering are common in earthquake time series, highlighting the complex nature of the earthquake generation process. In the present work we intr...

Observational indications support the hypothesis that many large earthquakes are preceded by accelerating-decelerating seismic release rates which are described by a power law time to failure relation. In the present work, a unified theoretical framework is discussed based on the ideas of non-extensive statistical physics along with fundamental pri...

The Yellowstone Park volcanic field is one of the most active volcanic systems in the world, presenting intense seismic activity that is characterized by several earthquake swarms over the last decades. In the present work, we focused on the spatiotemporal properties of the recent earthquake swarms that occurred on December-January 2008-2009 and th...

The substantial role of high-pressure fluids in the seismogenic process has long been recognized. Fluids can alter rock mechanical properties through fluid pressure and chemical reactions so that they play an integral role in lithospheric geodynamics. Chemical reactions inside the rock mass can reduce rock strength, while increased pore-pressure ca...

Monitoring seismic structural response is an essential issue in earthquake risk assessments and mitigation studies for monumental buildings in order to undertake earthquake disaster management. This study aims at identifying the resonant frequency of soil and modern and historical buildings in three major municipalities of Crete (Heraklion, Chania,...

The essential goals of this paper are to test the transient electromagnetic (TEM) response in a fractured geological complex medium and to better understand the physics introduced by associating a roughness parameter β to the geological formation. An anomalous fractional diffusion approach is incorporated to describe the electromagnetic induction i...

Triggered seismicity frequently presents characteristics of diffusion as it migrates away from a source area with time. Such phenomena can be more profound when linked to pore-fluid pressure diffusion that can reduce the effective normal stress along fault zones triggering earthquakes. Such processes can be highly anisotropic, occurring preferentia...

In the present work, magnesium diffusion in silicon studied recently in the temperature range 600–1200 °C (Astrov et al. in Phys Status Solidi A 214:1700192, 2017; Shuman et al. in Semiconductors 51:5, 2017) is investigated on the basis of the cBΩ thermodynamic model, which connects point defect parameters with the macroscopic elastic and expansion...

Crete Island (Greece), located in the front of the Hellenic subduction zone, is in continuous need of seismic monitoring. Aiming to increase seismic readiness and provide more knowledge-information to citizens and civil protection authorities, the Hellenic Seismological Network of Crete (HSNC) started operating a permanent strong ground motion (SGM...

Aim of the present work is to adapt and develop an algorithm for extracting first motion information from earthquake seismograms. In specifics, the present paper deals with the characterization of the ζ component of a given seismogram in order to discriminate an earthquake signal from noise recording. Segmentation and further classification of the...

The seismicity recorded during Ist January to 31st August 2005 from a new telemetry network installed and operating on the island of Crete, is used in an effort to obtain new velocity models for the area of south Aegean. The models are constructed from the P-waves travel time curves and are later used for the events relocation with the HYPOINVERSE...

Abstract The use of electrical and acoustic signals emission as fracture precursors when brittle materials like rocks are subjected to mechanical stress has been evaluated and found to be applicable by several researchers. A detailed review and description within the framework of the complexity approach will be performed on laboratory experiments...

How continental areas deform has been a subject of intense research, especially in the prism of plate tectonics. The distribution of seismicity in continental areas is not confined to a single fault, but earthquakes are distributed over wide zones, hundreds or even thousands wide, which contain many faults. Within these deforming zones, as for exam...

Fracture-induced phenomena in rocks and brittle materials that are subjected to mechanical stress include the emission of transient weak electric currents and elastic waves known as acoustic emissions (AE). These fractoemission phenomena are of great importance in searching precursory signals in mechanical damage of materials and in earthquakes pre...