A5010114716- earthquake and tectonic studies
- Seismology and Earthquake Studies
- High-pressure geophysics and materials
- Seismic Waves and Analysis
- Earthquake Detection and Analysis
- Seismic Imaging and Inversion Techniques
- Geological and Geochemical Analysis
- Anomaly Detection Techniques and Applications
- Geological and Geophysical Studies Worldwide
- Geological and Geophysical Studies
- Geophysics and Sensor Technology
- Seismic Performance and Analysis
National Observatory of Athens
2020-2025
University of Patras
2021-2025
National and Kapodistrian University of Athens
2018-2019
Abstract Physical laws governing friction on shallow faults in the Earth and spatial heterogeneity of parameters are critical to our understanding earthquake physics assessment hazards. Here we use a laboratory-derived fault-friction law high-quality strong-motion seismic recordings 2020 Elazığ earthquake, Turkey, reveal complex rupture dynamics. We discover an initial Mw 5.8 stage explain how cascading behavior event, involving at least three episodes, each M > 6, caused it evolve into...
ABSTRACT Local soil conditions significantly influence the characteristics of observed seismic waves, often obscuring or distorting original source signature and modifying recorded waveforms. backprojection (BP) imaging, a common technique for identifying spatiotemporal high-frequency energy release during ruptures, typically relies on strong motion data that is frequently not installed bedrock. We evaluate impact effects local BP images by analyzing obtained from 2008 Iwate–Miyagi Nairiku...
Abstract The National Observatory of Athens data center for the European Integrated Data Archive (EIDA@NOA) is national and regional node that supports International Federation Digital Seismograph Networks related webservices seismic waveform coming from southeastern Mediterranean Balkans. At present, it serves eight permanent broadband strong-motion networks Greece Cyprus, individual stations Balkans, temporary aftershock deployments, earthquake engineering experimental facilities. EIDA@NOA...
Abstract We investigate a seismic crisis that occurred in the western Gulf of Corinth (Greece) between December 2020 and February 2021. This area is main focus Rift Laboratory (CRL) network, has been closely monitored with local seismological geodetic networks for 20 yr. The 2020–2021 evolved three stages: It started an Mw 4.6 event near northern shore Gulf, opposite Aigion, then migrated eastward toward Trizonia Island after 5.0 event, eventually culminated 5.3 ∼3 km northeast Psathopyrgos...
The Source Scanning Algorithm (SSA) was introduced (Kao and Shan, 2004; 2007) as an automated approach to detect locate seismic events without the need for phase picking. This algorithm works by stacking observed waveforms based on theoretical arrival times derived from a velocity model, under assumption of potential point source. It conducts grid search across multiple candidate source locations, identifying those that produce highest values (i.e., brightness) most probable hypocenters....
The 2024–2025 seismic sequence in the Santorini-Amorgos region demonstrates a complex evolution revealing interaction between tectonic and volcanic processes. In this study, detailed catalog is presented, generated for operational monitoring using machine-learning-based phase picking high-precision relocation methods. By late summer 2024, activity emerged beneath Santorini within caldera. January 2025 seismicity appeared at around 20 km Kolumbo volcano before migrating northeastward...
ABSTRACT The 2020 Mw 7.0 Samos earthquake (eastern Aegean Sea) provides a rare chance to study the ongoing interaction of normal and strike-slip faulting during an aftershock sequence in suspected transfer zone with differential deformation style. After assessing them for possible site-effect influence, we first backproject local strong-motion data elicit high-frequency (HF) radiation main seismic event using Source Scanning Algorithm. Our results indicate existence multiple HF radiators...
Abstract This article introduces the first version of SSA2py (v.1.0)—an open-source package designed to implement source-scanning algorithm (SSA). is a Python-based, high-performance-oriented that incorporates SSA method, which has been effectively applied numerous earthquakes for imaging spatiotemporal behavior seismic source. The software supports wide range data and metadata resources. These include International Federation Digital Seismograph Networks Web Services, SeedLink protocol,...
Abstract Moderate‐to‐large earthquakes in rifts may occur on leading boundary faults or inner antithetic faults. Here we show a rare case of the 2020–2021 seismic sequence Corinth rift, that culminated shallow rupture fault, neither preceded nor followed by fault rupture. The hypocenter largest shock (Mw 5.3 17 February 2021) was located at ∼8 km depth. However, waveform data, supported satellite‐geodetic and tide gauge measurements, pointed to depth (∼3 km), where no were previously...
This report presents the 2022-2023 South Evia island seismic sequence, in western Aegean sea. An automated workflow, undergoing testing for efficient observatory monitoring wake of dense aftershock sequences, was employed to enhance catalog. It includes a deep-learning phase picker, absolute and relative hypocenter relocation, moment tensor automatic calculations. The relocated catalog reveals concentration earthquake epicenters narrow NW-SE zone, with sinistral strike-slip fault movement....
ABSTRACT In March 2021, a series of three moderate events with moment magnitudes Mw 6.3, 6.0, and 5.5 occurred within span 10 days in northern Thessaly, Greece, resulting stop–start pattern. The tensors (MTs) obtained from the suggested normal faulting along distinct yet adjacent southeast–northwest-trending faults, indicating sequential triggering process. We applied two methods to investigate spatial temporal characteristics source process triplet. This approach includes linear slip...
Abstract Automatic moment tensor (MT) determination is essential for real-time seismological applications. In this article, Gisola, a highly evolved software MT determination, oriented toward high-performance computing, presented. The program employs enhanced algorithms waveform data selection via quality metrics, such as signal-to-noise ratio, clipping, and metadata inconsistency, long-period disturbances, station evaluation based on power spectral density measurements in parallel...
<p>We introduce SSA2py, an open-source tool for the implementation of Source-Scanning Algorithm (SSA) (Honn Kao and Shao-Ju Shan, 2007) in near-real time conditions. In general, Back-Projection methods due to their simplistic but at same effective approach provide circumstances fast analysis seismic rupture with relatively low computational cost minimum initial assumptions.  accordance that by exploiting local strong motion data, SSA can be used detailed imaging...
<p>Automatic Moment Tensor (MT) determination for regional areas is essential real-time seismological applications such as stress inversion, shakemap generation, and tsunami warning. In recent years, the combination of two powerful tools, SeisComP ISOLA (Sokos Zahradník, 2008), paved way release Scisola (Triantafyllis et al., 2016), an open-source Python-based software automatic MT calculation seismic events provided by -a well-known package-, in real-time....
<p>The seismic source spatio-temporal rupture processes of events in Japan, Greece and Turkey are imaged by backprojection strong-motion waveforms. Normalized high-frequency (> 2Hz) S-waveforms from recordings on dense networks used to scan a predefined 3D volume over time. </p><p>Backprojection is an alternative novel approach image the earthquake rupture. The method was first applied for large earthquakes at teleseismic...
<p>On November 30, 2020 11:51 UTC, a major earthquake (Mw7.0) struck the northern area offshore Samos island, Greece, causing serious damage to island and nearby Turkish coast. This seismic event is an ideal opportunity explore extensional seismicity in back-arc of Hellenic subduction zone. To that end, first foremost we study behavior characteristics main source. Then, examine evolution aftershock space time relate it event. We implement technique local backprojection on...
<p>The 2020 Mw 6.8 Elazığ (Sivrice) earthquake occurred on the Pütürge segment of East Anatolian Fault zone. This strike-slip is situated between strong earthquakes that happened 100–150 years ago, and, since time, remained with eight Mw5-6 events, but no 6+. We relocate mainshock and aftershock sequence infer basic characteristics event using ISOLA multiple point source approach backpropagation S-waveforms from...