The 2020-2021 seismic sequence in the Western Gulf of Corinth: Insights on the triggering mechanisms through high resolution seismological and geodetic data analysis

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10473399" target="_blank" >RIV/00216208:11320/23:10473399 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Vb6GfsN3mG" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Vb6GfsN3mG</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tecto.2023.230011" target="_blank" >10.1016/j.tecto.2023.230011</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The 2020-2021 seismic sequence in the Western Gulf of Corinth: Insights on the triggering mechanisms through high resolution seismological and geodetic data analysis

Popis výsledku v původním jazyce

The 2020-2021 seismic sequence at the Western Gulf of Corinth, Central Greece, has been thoroughly analyzed using seismological and geodetic data processing. We present a high-resolution dataset of over 4000 relocated earthquakes between June 2020 and February 2021, delineating the activated structures. We examine the evolution of various clusters that were triggered during a three-stage sequence which began on December 23, 2020, with an Mw = 4.6 event near Marathias, migrated eastwards, following an Mw = 5.0 event on January 12, 2021 near Trizonia Island, and culminated on February 17 with an Mw = 5.3 offshore event north of Psatho-pyrgos. Focal mechanisms for the 20 stronger events, determined by moment tensor inversion, and 36 weaker ones, obtained through first motion polarities measurements, revealed dominant normal faulting. The fault plane of the February 17, 2021 major event is modeled through the inversion of geodetic data. Results suggest a very shallow geodetic centroid at 1.5 km depth, consistent with the seismic centroid (3.5 km), but different from the relocated hypocenter (7.5 km). Spatiotemporal analysis reveals seismic migration, following a diffusion law with D values in the range 0.06-0.25 m2s  1, consistent with triggering due to pore-pressure diffusion by fluids intrusion. This enables failure on non-optimally oriented faults, which explains the significant proportion of the observed strike-slip and oblique-normal faulting. Coulomb stress transfer due to the major events shows only weak stress-loading on the fault of the January 12, 2021 earthquake and a higher level of positive stress transfer to the south-dipping than to the north-dipping nodal plane of the 17 February event. The latter could have facilitated the nucleation of the rupture at 7.5 km and its further propagation to shallower depths along a south-dipping plane, where the bulk of its seismic and geodetic moment was released.

Název v anglickém jazyce

The 2020-2021 seismic sequence in the Western Gulf of Corinth: Insights on the triggering mechanisms through high resolution seismological and geodetic data analysis

Popis výsledku anglicky

The 2020-2021 seismic sequence at the Western Gulf of Corinth, Central Greece, has been thoroughly analyzed using seismological and geodetic data processing. We present a high-resolution dataset of over 4000 relocated earthquakes between June 2020 and February 2021, delineating the activated structures. We examine the evolution of various clusters that were triggered during a three-stage sequence which began on December 23, 2020, with an Mw = 4.6 event near Marathias, migrated eastwards, following an Mw = 5.0 event on January 12, 2021 near Trizonia Island, and culminated on February 17 with an Mw = 5.3 offshore event north of Psatho-pyrgos. Focal mechanisms for the 20 stronger events, determined by moment tensor inversion, and 36 weaker ones, obtained through first motion polarities measurements, revealed dominant normal faulting. The fault plane of the February 17, 2021 major event is modeled through the inversion of geodetic data. Results suggest a very shallow geodetic centroid at 1.5 km depth, consistent with the seismic centroid (3.5 km), but different from the relocated hypocenter (7.5 km). Spatiotemporal analysis reveals seismic migration, following a diffusion law with D values in the range 0.06-0.25 m2s  1, consistent with triggering due to pore-pressure diffusion by fluids intrusion. This enables failure on non-optimally oriented faults, which explains the significant proportion of the observed strike-slip and oblique-normal faulting. Coulomb stress transfer due to the major events shows only weak stress-loading on the fault of the January 12, 2021 earthquake and a higher level of positive stress transfer to the south-dipping than to the north-dipping nodal plane of the 17 February event. The latter could have facilitated the nucleation of the rupture at 7.5 km and its further propagation to shallower depths along a south-dipping plane, where the bulk of its seismic and geodetic moment was released.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10500 - Earth and related environmental sciences

Projekt

<a href="/cs/project/GA23-06345S" target="_blank" >GA23-06345S: Seismo-geodynamické modelování Helénské subdukce</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Tectonophysics

ISSN

0040-1951

e-ISSN

1879-3266

Svazek periodika

863

Číslo periodika v rámci svazku

August

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

22

Strana od-do

230011

Kód UT WoS článku

001068437200001

EID výsledku v databázi Scopus

2-s2.0-85169605580