@article{2-s2.0-105044321038,

title = {HOMEROS Open Science: integrated seismological and geodetic ecosystems},

author = { S. Bitharis and C. Pikridas and I.A. Karolos and V.G. Karakostas and E.E. Papadimitriou and P. Bonatis and V. Anagnostou and C. Kourouklas and G. Kaviris and I. Spingos and A. Zymvragakis and V.A. Sakkas},

url = {https://www.scopus.com/pages/publications/105044321038?origin=resultslist},

doi = {10.31577/congeo.2026.56.2.2},

issn = {13352806},

year  = {2026},

date = {2026-01-01},

journal = {Contributions to Geophysics and Geodesy},

volume = {56},

number = {2},

pages = {121-147},

publisher = {Slovak Academy of Sciences},

abstract = {The HOMEROS project advances multi-hazard assessment through the integrated use of seismological and geodetic infrastructures within an Open Science framework. This paper presents the seismological and GNSS-based geodetic networks, data products, and processing workflows that underpin hazard monitoring and analysis in tectonically active regions of Greece, with emphasis on the central Ionian Islands and the western Gulf of Corinth. Dense permanent seismic networks provide high-resolution waveform data enabling precise earthquake detection, relocation, and source characterization. Complementary GNSS infrastructures, such as the Hermes network and GL-NKUA cGNSS, deliver continuous observations processed using Precise Point Positioning and kinematic techniques to quantify crustal deformation displacements, and atmospheric parameters. Integrated quality control, standardised processing pipelines, and interoperability through EPOS, EIDA, and institutional repositories ensure compliance with the FAIR data principles. The combined seismological and geodetic datasets support advanced applications, including high-accuracy earthquake catalogues, deformation monitoring, and physics-based ground motion simulations for seismic hazard assessment, demonstrated through seismic crises in the study areas. By harmonising heterogeneous observations and products, HOMEROS enhances reproducibility, data reuse, and collaborative research, providing a robust testbed for multi-hazard assessment in Greece and a transferable model for the broader European and global research community. © 2026 Slovak Academy of Sciences. All rights reserved.},

note = {0},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-105040783476,

title = {A sequential Monte Carlo framework for the physical modeling of post-seismic transients},

author = { P. Bonatis and V.E. Papageorgiou and P. Bountzis and V.G. Karakostas and G.M. Tsaklidis},

url = {https://www.scopus.com/pages/publications/105040783476?origin=resultslist},

doi = {10.1016/j.geog.2026.03.009},

issn = {16749847},

year  = {2026},

date = {2026-01-01},

journal = {Geodesy and Geodynamics},

publisher = {KeAi Communications Co.},

abstract = {Post-seismic deformation encompasses the complex adjustment of the crust and upper mantle following large earthquakes, often continuing for years to decades. Accurately modeling these transients remains challenging due to nonlinear processes, observational noise, and incomplete data. We present a Sequential Monte Carlo (SMC) framework for estimating post-seismic deformation that uses particle filtering (PF) to track the evolving deformation signal and the associated parameters in a fully stochastic setting. Using synthetic GNSS time series spanning logarithmic, exponential, mixed logarithmic-exponential and stretched exponential transient behaviors, we assess model performance under realistic noise levels and data gaps. Compared with a grid-based method and standard MCMC, our approach yields systematically lower fitting errors and more stable parameter estimates, with the true synthetic values recovered within narrower 95% credible intervals. The PF scheme further enables online estimation of both the latent deformation state and the time-varying parameters, maintaining robust performance even when only truncated segments of the time series are available. From a statistical perspective, the logarithmic–exponential model shows the best fitting performance, whereas the stretched exponential formulation offers a compact and physically interpretable alternative. Application to long-term GNSS observations after the 2011 MW9.0 Tohoku earthquake demonstrates that the proposed framework successfully captures complex, multi-timescale post-seismic signals in a heterogeneous tectonic setting. Finally, the results highlight PF as a promising tool for the robust estimation of post-seismic deformation in both real-time and retrospective analyses. © 2026 Editorial office of Geodesy and Geodynamics},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-105049536521,

title = {Post-seismic deformation associated with the 2020 MW7.0 Samos (Aegean Sea) earthquake constrained by InSAR and GNSS observations},

author = { P. Bonatis and V.G. Karakostas and M. Foumelis and E.E. Papadimitriou and J. Kapłon and G. Kaviris and C. Pikridas},

url = {https://www.scopus.com/pages/publications/105049536521?origin=resultslist},

doi = {10.1016/j.geog.2026.08.005},

issn = {16749847},

year  = {2026},

date = {2026-01-01},

journal = {Geodesy and Geodynamics},

publisher = {KeAi Communications Co.},

abstract = {This study investigates the post-seismic deformation following the October 30, 2020 MW7.0 Samos earthquake using Copernicus Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) time series and continuous Global Navigation Satellite System (GNSS) observations spanning more than four years after the main shock. Prior to the post-seismic analysis, a reference co-seismic slip model was derived from co-seismic GNSS offsets within a seismologically constrained finite-fault geometry. Post-seismic deformation is largely confined to Samos Island, with no resolvable signal detected on adjacent islands or along the Turkish coast, indicating a near-field-dominated response. The post-seismic deformation within Samos Island is spatially asymmetric, characterized by sharp displacement gradients in the western and central parts of the island and smoother deformation towards the east. The joint inversion of GNSS and InSAR data indicates that post-seismic deformation is dominated by shallow afterslip concentrated primarily up-dip and laterally adjacent to the co-seismic rupture. Peak cumulative afterslip reaches ∼0.6 m, releasing a post-seismic moment equivalent to approximately 20% of the co-seismic one. The spatial relationship between the co-seismic slip, afterslip, and aftershocks suggests efficient stress release during the main rupture, followed by aseismic afterslip on shallow parts of the fault plane. Localized deviations from the afterslip model, particularly in coastal areas, imply that poroelastic rebound may have contributed secondarily to the post-seismic deformation. © 2026 Editorial office of Geodesy and Geodynamics},

note = {0},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85208074268,

title = {The 2022 Mw5.5 earthquake off-shore Kefalonia Island – relocated aftershocks, statistical analysis and seismotectonic implications},

author = { P. Bonatis and V.G. Karakostas and E.E. Papadimitriou and C. Kourouklas},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85208074268&doi=10.1007%2fs10950-024-10255-y&partnerID=40&md5=3dff53a9f5042a06d93fa9a3f6697b25},

doi = {10.1007/s10950-024-10255-y},

year  = {2025},

date = {2025-01-01},

journal = {Journal of Seismology},

volume = {29},

number = {5},

pages = {987-1003},

publisher = {Springer Science and Business Media B.V.},

abstract = {We investigate the properties of a seismic sequence occurred close to the southwestern edge of the Kefalonia Transform Fault Zone where a decadal relative quiescence was observed. The moderate Mw5.5 main shock occurred on 8 September 2022, close to the 1983 M7.0 rupture zone. We compiled a precisely relocated aftershock catalog of a low magnitude of completeness (Mc = 1.8) aiming to identify the seismicity patterns and reveal the characteristics of the spatiotemporal seismicity evolution. The appreciable aftershock activity lasted for almost 4 months being spatially distributed along a NE-SW elongated zone with a length of approximately 16 km. The focal mechanism of the main shock along with the spatial distribution of aftershocks revealed the activation of a dextral strike-slip fault segment. Statistical analysis of the aftershock activity indicated that it conforms to the Mainshock-Aftershock type, with aftershock occurrence decaying rapidly over time indicating a low aftershock productivity. Coulomb stress changes analysis revealed that the expansion of the aftershock zone was strongly affected by the stress transferred by the main rupture. The state of stress in the area before the occurrence of the main shock explains the activation of this fault segment, which could be associated with the structure that accommodated the large 1983 M7.0 earthquake. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.},

note = {5},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-105009700991,

title = {Triggering mechanisms and repeating earthquakes during the intense 2020-2021 seismic crisis in the Gulf of Corinth},

author = { P. Bountzis and C. Kourouklas and P. Bonatis and V.G. Karakostas and E.E. Papadimitriou and A. Kostoglou},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-105009700991&doi=10.1093%2fgji%2fggaf181&partnerID=40&md5=103fbce0863a98266dad941d0d1110b2},

doi = {10.1093/gji/ggaf181},

year  = {2025},

date = {2025-01-01},

journal = {Geophysical Journal International},

volume = {242},

number = {2},

publisher = {Oxford University Press},

abstract = {The 2020-2021 seismic crisis in the western Gulf of Corinth was characterized by a sustained duration and the activation of multiple neighbouring fault segments. Using a high-resolution microseismicity data set we explored the possible mechanisms driving this activity, which appeared migrating in time across the local fault network. Applying the density-based clustering algorithm, DBSCAN, we identified 95 repeaters comprised in 19 multiplets, each multiplet containing at least four earthquakes, the majority of which () occurring during the first phase of the activity. The analysis of the migration front revealed a complex interplay of triggering mechanisms. An average migration velocity of was estimated for the entire duration, with fluid-induced aseismic slip emerging as a potential driving force during the first period, along with intermediate faster migration rates () during rapid bursts of activity. Coulomb stress modelling further demonstrated a cascading stress transfer among the activated fault segments, progressively triggering the larger earthquakes over time. Statistical modelling based on the Epidemic Type Aftershock Sequence model highlighted the coexistence of swarm-like activity nested within mainshock-aftershock sequences, offering insights into the dynamic evolution of seismicity. These findings highlight the complex mechanisms that drive the evolution of the seismicity, where aseismic slip appears to act as the main triggering mechanism for the first major rupture of the seismic activity, followed by stress perturbations. © 2025 The Author(s).},

note = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85201787277,

title = {Co-seismic and post-seismic slip associated with the 2021 Mw5.9 Arkalochori, Central Crete (Greece) earthquake constrained by geodetic data and aftershocks},

author = { P. Bonatis and V.G. Karakostas and J. Kapłon and E.E. Papadimitriou and G. Kaviris and M. Ilieva and M. Foumelis and C. Pikridas},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85201787277&doi=10.1016%2fj.tecto.2024.230481&partnerID=40&md5=5aa8943637fc2adc10b28357640ec136},

doi = {10.1016/j.tecto.2024.230481},

year  = {2024},

date = {2024-01-01},

journal = {Tectonophysics},

volume = {889},

publisher = {Elsevier B.V.},

abstract = {The co-seismic and post-seismic deformation field associated with the Mw5.9 Arkalochori main shock that occurred in central Crete (Greece) on 27 September 2021 is analyzed using Copernicus Sentinel-1A & 1B images, GNSS measurements and seismological data. The fault geometry is constrained through the joint inversion of multiple datasets and the slip distribution for the co-seismic and post-seismic period is obtained using a homogeneous half-space elastic model and the Steepest Descent Method. The results indicate a blind normal fault striking 215° with a 55° dip to the northwest and the co-seismic slip model suggests a nearly circular main slip patch (8 × 6 km2) with a maximum slip of 0.98 m. Post-seismic displacements started rapidly after the main shock followed by a gradual decay as highlighted by the calculated InSAR time series. The temporal evolution of post-seismic slip is described by a simple logarithmic function, decaying faster at the southwest part of the fault. The cumulative afterslip model suggests that the maximum post-seismic slip of 0.23 m occurred within a similar depth range compared to the co-seismic one, yet with a shift towards the southwest. Post-seismic slip inside the main shock rupture area is sustained, highlighting the slow recovery of locking in the co-seismic slip region. Afterslip (seismic or aseismic) played a dominant role in the early post-seismic period acting complementarily to the main rupture. Indications suggest that the spatiotemporal evolution of the productive aftershock sequence may be driven afterslip, alongside other potential factors. © 2024 Elsevier B.V.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85165194036,

title = {A Logic-Tree Approach for Probabilistic Seismic Hazard Assessment in the Administrative Region of Attica (Greece)},

author = { G. Kaviris and A. Zymvragakis and P. Bonatis and V. Kapetanidis and I. Spingos and S.D. Mavroulis and E. Kotsi and E.L. Lekkas and N.S. Voulgaris},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85165194036&doi=10.3390%2fapp13137553&partnerID=40&md5=b410f94d7611105659ec27e59e84a735},

doi = {10.3390/app13137553},

year  = {2023},

date = {2023-01-01},

journal = {Applied Sciences (Switzerland)},

volume = {13},

number = {13},

publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},

abstract = {Probabilistic Seismic Hazard Assessment (PSHA) was carried out for the administrative region of Attica (Greece). Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV) values were calculated for return periods of 475 and 950 years for five sub-areas covering the entire region. PGA hazard curves and Uniform Hazard Spectra (UHS) in terms of spectral acceleration (Sa) values were generated for Athens, Methana, and the capitals of each island of Attica (Salamina; Aegina; Poros; Hydra; Spetses; Kythira; and Antikythira). Area sources were adopted from the Euro-Mediterranean Seismic Hazard Model 2013 (ESHM13) and its update, ESHM20, taking into account both crustal and slab tectonic environments. Ground Motion Prediction Equations (GMPEs) proposed for the Greek territory were ranked for PGA and PGV. Each GMPE was reconstructed as a weighted model, accounting for normal and non-normal focal mechanisms for each area source. PGA, PGV, and Sa values were computed using a logic tree, integrating the seismotectonic models as major branches and sub-logic trees, comprised of multiple ranked GMPEs for each area source, as minor branches. The results showed higher seismic hazard values in sub-areas near the Gulf of Corinth and the slab interface, which could indicate a need to revise the active building code in Attica. © 2023 by the authors.},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85166475152,

title = {The seismogenic structure of March 2021 Tyrnavos (central Greece) doublet (Mw 6.3 and Mw 6.0), constrained by aftershock locations and geodetic data},

author = { E.E. Papadimitriou and V.G. Karakostas and C.B. Papazachos and M. Foumelis and A.A. Kiratzi and C. Pikridas and P. Bonatis and A. Kostoglou and C. Kourouklas and E.M. Scordilis and S. Bitharis and P.M. Paradisopoulou and A.A. Panou and O.C. Galanis and E.E. Karagianni and D.A. Vamvakaris and I. Karagianni and C. Kkallas and N. Chatzis and A.A. Chatzipetros and A. Fotiou and C. Ventouzi and I. Grendas and D. Kementzetzidou and G.F. Karakaisis and P.M. Hatzidimitriou},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85166475152&doi=10.1093%2fgji%2fggad253&partnerID=40&md5=243734359507aae39063abacbf0557bc},

doi = {10.1093/gji/ggad253},

year  = {2023},

date = {2023-01-01},

journal = {Geophysical Journal International},

volume = {235},

number = {1},

pages = {644-689},

publisher = {Oxford University Press},

abstract = {The Northern Thessaly Basin in central Greece ranks amongst the most well pronounced extensional (graben) basins in the backarc Aegean Sea region, with well-mapped faults having an ∼E–W orientation, compatible with the ongoing predominant ∼N–S extension. The southern margin of the basin is bounded by major faults associated with strong (M6 to M7) earthquakes, whereas along its northern margin, strong events are more scarce, in the documented catalogues. Along this northern margin, a weak, albeit persisting foreshock activity, culminated within 3 d, to an Mw 6.3 earthquake on 3 March 2021 associated with a 15-km-long NE dipping fault segment. It was followed the next day, by the second Mw 6.0 main shock associated with a 13-km-long NE dipping fault segment and 9 d later by an Mw 5.5 earthquake associated with an 8-km-long SW dipping fault segment, with its aligned epicentres, showcasing the cascade type activation of adjacent fault segments. The sequence, evolved to be very productive, with aftershocks extending ∼50 km along a ∼NW–SE trending narrow seismic zone. All events indicate pure normal faulting, with an NNE–SSW oriented extensional axis, oblique to our previous consensus of the prevalence of ∼N–S extension. This observation documents that inherited fault fabric can be reactivated within the modern tectonic stress field. We use high-quality seismological data, alongside Interferometric Synthetic Aperture Radar (InSAR) methodology and Global Navigation Satellite System (GNSS) data, to study the temporal and spatial evolution of the sequence, and to provide inferred kinematic models that describe the complexity of the seismic process, in terms of heterogeneous slip distribution, activated fault planes, fault geometry and displacement field. Cross-sections show that the activity defines the crustal seismogenic layer at depths between 5 and 10 km, associated with low-angle fault segments dipping to the NE. Other faults, both antithetic and secondary ones, appear active and accommodated aftershocks clusters. Using our preferred finite fault source model, we calculated the changes of Coulomb failure stress on the neighbouring faults. C The Author(s) 2023. Published by Oxford University Press on behalf of The Royal Astronomical Society.},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85141854163,

title = {Probabilistic and Scenario-Based Seismic Hazard Assessment on the Western Gulf of Corinth (Central Greece)},

author = { G. Kaviris and A. Zymvragakis and P. Bonatis and V. Kapetanidis and N.S. Voulgaris},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141854163&doi=10.3390%2fapp122111152&partnerID=40&md5=c08ed8a6e0eb33d106b94a7150287ea4},

doi = {10.3390/app122111152},

year  = {2022},

date = {2022-01-01},

journal = {Applied Sciences (Switzerland)},

volume = {12},

number = {21},

publisher = {MDPI},

abstract = {The Gulf of Corinth (Central Greece) is one of the most rapidly extending rifts worldwide, with its western part being the most seismically active, hosting numerous strong (M ≥ 6.0) earthquakes that have caused significant damage. The main objective of this study was the evaluation of seismic hazard through a probabilistic and stochastic methodology. The implementation of three seismotectonic models in the form of area source zones via a logic tree framework revealed the expected level of peak ground acceleration and velocity for return periods of 475 and 950 years. Moreover, PGA values were obtained through the stochastic simulation of strong ground motion by adopting worst-case seismic scenarios of potential earthquake occurrences for known active faults in the area. Site-specific analysis of the most populated urban areas (Patras; Aigion; Nafpaktos) was performed by constructing uniform hazard spectra in terms of spectral acceleration. The relative contribution of each selected fault segment to the seismic hazard characterizing each site was evaluated through response spectra obtained for the adopted scenarios. Almost all parts of the study area were found to exceed the reference value proposed by the current Greek National Building Code; however, the three urban areas are covered by the Eurocode 8 regulations. © 2022 by the authors.},

note = {14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85123469061,

title = {Probabilistic Seismic Hazard Assessment for the Broader Messinia (SW Greece) Region},

author = { G. Kaviris and A. Zymvragakis and P. Bonatis and G. Sakkas and V. Kouskouna and N.S. Voulgaris},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123469061&doi=10.1007%2fs00024-022-02950-z&partnerID=40&md5=1ccb30bb37e6482eaa45d7f56a246af7},

doi = {10.1007/s00024-022-02950-z},

year  = {2022},

date = {2022-01-01},

journal = {Pure and Applied Geophysics},

volume = {179},

number = {2},

pages = {551-567},

publisher = {Birkhauser},

abstract = {Messinia is located in SW Peloponnese (Greece), in the vicinity of the Hellenic Arc which is one of the most seismically active areas of Europe. The arc is dominated by reverse faulting, whereas normal faults are mapped onshore, mainly striking N–S. Large earthquakes have occurred in the study area, both in the historical and instrumental periods. In the present study, a Probabilistic Seismic Hazard Assessment (PSHA) is applied to estimate the Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Peak Ground Rotational Acceleration (PGRA) and Peak Ground Rotational Velocity (PGRV) for the broader Messinia region. PGRA and PGRV are not often examined in detail in the literature, even though they are useful for the evaluation of the possible damages in structures. The widely used approach proposed by Cornell and McGuire is implemented taking into account: (a) the seismotectonic model proposed by Seismic Hazard Harmonization in Europe (SHARE), (b) an earthquake catalogue for the instrumental period and (c) Ground Motion Prediction Equations (GMPEs) proposed for the Greek territory. The computational grid spacing for Messinia was set to 1 km, in order to accurately calculate the hazard parameters and to reduce the bias of the results through interpolation processes. For PGA and PGV, a logic tree approach is considered, where every branch is a hybrid version of each GMPE considering the percentage of the type (normal or non-normal) of focal mechanisms for all zones of the seismotectonic model. The results show an increase of the hazard values in the NW part of the study area, where the Greek Building Code provides lower PGA values. In addition, hazard curves in terms of PGA for multiple probabilities of exceedance in 50 years are determined for five major towns of Messinia, i.e. Kalamata, Messini, Filiatra, Kyparissia and Pylos. Kyparissia has the higher hazard in all probabilities of exceedance, which is in full agreement with the PGA and PGV results. Pylos and Filiatra have intermediate to high hazard, whereas Kalamata and Messini show intermediate hazard values. Furthermore, the Uniform Hazard Spectrum (UHS) in terms of Spectral Acceleration for the same towns is computed. The latter provides essential information about the design parameters. Lastly, the results are compared to the seismic histories of the five major towns in terms of European Macroseismic Scale (EMS98) intensity, plotted for the last 200 years. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85137501095,

title = {The Intense 2020–2021 Earthquake Swarm in Corinth Gulf: Cluster Analysis and Seismotectonic Implications from High Resolution Microseismicity},

author = { E.E. Papadimitriou and P. Bonatis and P. Bountzis and A. Kostoglou and C. Kourouklas and V.G. Karakostas},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137501095&doi=10.1007%2fs00024-022-03135-4&partnerID=40&md5=92b9e773649267ae108c7f45c5a6a606},

doi = {10.1007/s00024-022-03135-4},

year  = {2022},

date = {2022-01-01},

journal = {Pure and Applied Geophysics},

volume = {179},

number = {9},

pages = {3121-3155},

publisher = {Birkhauser},

abstract = {The intense 2020–2021 seismic crisis in Corinth gulf, Greece, comprising several hundreds of small earthquakes (maximum magnitude Mw = 5.4 on 17 February 2021) is investigated. The spatial and temporal evolution of the seismicity implied the activation of multiple secondary fault segments. To decipher the geometry of the activated structures, we engaged relocation techniques and obtained the precise locations for 3398 earthquakes and 26 moment tensor solutions. The highly accurate seismicity locations and focal mechanisms illustrate the fine scale faulting geometry of a ~ 10–km–long activated area, almost east west striking and north dipping, and extensional kinematics. We grouped events into clusters using nearest–neighbor distances between them and a temporal stochastic point process, the Markovian Arrival Process (MAP). We identified clusters that evidence seismicity migration and organization in both space and time, deciphering the interaction of even tiny fault segments in a fault network. The exhaustive analysis of the swarm spatiotemporal evolution revealed several either distinct or contiguous activated minor fault segments that evolved in multiple structures, participating in the local fracture mesh. Faulting geometry and kinematics of these structures agree with the ~ N–S extension of the rift and north dipping fault planes. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.},

note = {13},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85138641594,

title = {Investigation of the Factors Controlling the Duration and Productivity of Aftershocks Following Strong Earthquakes in Greece},

author = { P. Bonatis and V.G. Karakostas and E.E. Papadimitriou and G. Kaviris},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138641594&doi=10.3390%2fgeosciences12090328&partnerID=40&md5=ed03e78f6147933294a5e8f0f6cb0f8a},

doi = {10.3390/geosciences12090328},

year  = {2022},

date = {2022-01-01},

journal = {Geosciences (Switzerland)},

volume = {12},

number = {9},

publisher = {MDPI},

abstract = {Strong crustal earthquakes in Greece are typically followed by aftershocks, the properties of which are important factors in seismic hazard assessment. In order to examine the properties of earthquake sequences, we prepared an earthquake catalog comprising aftershock sequences with mainshocks of Mw ≥ 5.5 from 1995 to 2021. Regional aftershock parameters were estimated to highlight variations in aftershock decay and productivity among regions with similar seismotectonic characteristics. A statistically based method of estimating aftershock duration and a metric of relative aftershock productivity to examine the variations among the different cases were employed. From the detailed analysis of the selected seismic sequences, we attempt to unravel the physical mechanisms behind deviations in aftershock duration and productivity and resolve the relative contribution of background seismicity, the Omori–Utsu law parameters and the mainshock faulting properties. From our analysis, the duration of aftershock sequences depends upon the rupture process of the mainshock, independently of its magnitude. The same applies to aftershock productivity, however, other tectonic setting (e.g.; seismic coupling) or source-related (e.g.; focal depth; stress drop) parameters also contribute. The estimated regional parameters of the aftershock rate models could be utilized as initial ones to forecast the aftershock occurrence rates at the early stage following a mainshock. © 2022 by the authors.},

note = {10},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85111078248,

title = {Near-Fault Broadband Ground Motion Simulation Applications at the Central Ionian Islands, Greece},

author = { P. Bonatis and A. Akinci and V.G. Karakostas and E.E. Papadimitriou and G. Kaviris},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111078248&doi=10.1007%2fs00024-021-02825-9&partnerID=40&md5=823addcb0a81d46c9ad7b3029abab62d},

doi = {10.1007/s00024-021-02825-9},

year  = {2021},

date = {2021-01-01},

journal = {Pure and Applied Geophysics},

volume = {178},

number = {9},

pages = {3505-3527},

publisher = {Birkhauser},

abstract = {Physics-based broadband ground-motion simulations are generated for the strong mainshocks that occurred in the region of the Central Ionian Islands, on 26th January 2014 in Kefalonia (Mw6.1) and 17th November 2015 in Lefkas (Mw6.5). The study area is associated with frequent strong earthquakes both in the historical and instrumental era. During the last decades the network of strong-motion accelerographs in the area has been densified, and thus provided an adequate number of strong ground motion records as a means to better examine the related ground motion characteristics. In the present study, broadband ground motions for the two case studies are simulated both at selected sites and at a dense grid of points covering the affected areas. The low-frequency part of the synthetics is computed using a discrete wavenumber finite element method by convolving Green’s functions with a kinematic slip model in the frequency domain. A stochastic finite fault model approach based on a dynamic corner frequency is considered to calculate the ground motions for the higher frequencies. The broadband synthetic time series are generated after merging the results obtained from the two separate techniques, by performing a weighted summation at intermediate frequencies. The simulated values are validated by comparison with both recorded Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV) values and the estimated ones by using widely accepted Ground Motion Prediction Equations (GMPEs). Our results indicate that both the spatial distribution and the amplification pattern of the simulated ground motions, in the near-field, in terms of PGA and PGV are highly influenced by the slip heterogeneity and the maximum slip patches within the seismic source. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.},

note = {14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85103390270,

title = {Seismotectonic implications of the 2020 Samos, Greece, M w 7.0 mainshock based on high-resolution aftershock relocation and source slip model},

author = { V.G. Karakostas and O. Tan and A. Kostoglou and E.E. Papadimitriou and P. Bonatis},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103390270&doi=10.1007%2fs11600-021-00580-y&partnerID=40&md5=98f18bc3bde1236325ba1d84824da42b},

doi = {10.1007/s11600-021-00580-y},

year  = {2021},

date = {2021-01-01},

journal = {Acta Geophysica},

volume = {69},

number = {3},

pages = {979-996},

publisher = {Springer Science and Business Media Deutschland GmbH},

abstract = {The 30 October 2020, Mw 7.0 Samos mainshock took place in the offshore north of Samos Island in eastern Aegean area, previously struck in 1904 with a comparable magnitude earthquake offshore the southern coastline. The investigation of the aftershock seismicity evolution and the properties of the activated fault network was accomplished with aftershock relocation performed with the double-difference and cross-correlation techniques. The highly accurate relocated seismicity illustrates a well-defined E–W activated structure located deeper than 5 km with an average depth of ~ 12 km. Moment tensor solutions indicate mostly normal faulting with an average T-axis ~ 185ο. Strong-motion waveform modeling revealed a N-dipping fault plane with a coseismic slip patch of 36 km × 22 km and a maximum slip equal to 1 m at 12 km depth. The slip is mainly concentrated in a single asperity implying a rupture mode of asperities breaking in isolated earthquakes rather than to cooperate to produce a larger rupture. Coulomb stress calculations unveil increased positive static stress changes values at the locations of the majority of the aftershocks and activation of minor fault segments by stress transfer. © 2021, Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences.},

note = {33},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85109403384,

title = {Correction to: Seismotectonic implications of the 2020 Samos, Greece, M w 7.0 mainshock based on high‐resolution aftershock relocation and source slip model (Acta Geophysica, (2021), 69, 3, (979-996), 10.1007/s11600-021-00580-y)},

author = { V.G. Karakostas and O. Tan and A. Kostoglou and E.E. Papadimitriou and P. Bonatis},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109403384&doi=10.1007%2fs11600-021-00637-y&partnerID=40&md5=e24bdf5f6770dea8ca08776374db29ad},

doi = {10.1007/s11600-021-00637-y},

year  = {2021},

date = {2021-01-01},

journal = {Acta Geophysica},

volume = {69},

number = {3},

pages = {997-},

publisher = {Springer Science and Business Media Deutschland GmbH},

abstract = {In the original version of this article, the reference list for the kinematic source inversion algorithm provided us by Yuji Yagi is incomplete. © 2021, Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}