Complex Dynamic Rupture of an Mw5.8 Intermediate-Depth Earthquake in the Hellenic Slab

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10508352" target="_blank" >RIV/00216208:11320/25:10508352 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=8ATLk.e6dj" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=8ATLk.e6dj</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2024GL113649" target="_blank" >10.1029/2024GL113649</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Complex Dynamic Rupture of an Mw5.8 Intermediate-Depth Earthquake in the Hellenic Slab

Popis výsledku v původním jazyce

Earthquakes in the Hellenic slab, traced by tomography down to 1,200 km, occur at depths &lt;200 km with enigmatic origin and dynamics. We study a 2014 Mw5.8 left-lateral strike-slip earthquake originating at a depth of similar to 90 km under arc-parallel compression, featuring a small implosive component of the moment tensor. We use well-recorded aftershock as an empirical Green&apos;s function to infer reliable apparent source time functions up to 2 Hz. They exhibit multiple peaks with pronounced directivity and serve as input data to infer kinematic and dynamic rupture evolution in Bayesian source inversion. Our finite-fault kinematic and dynamic source models consistently reveal episodic behavior with two prominent asperities, short rupture duration, unilateral propagation, and locally high rupture speed and stress drop. We speculate the event was triggered and driven by dehydration and stress transfer associated with shear deformation and rock compaction. Plain Language Summary Intermediate-depth earthquakes (60-300 km) occur in subduction zones and their origin is often attributed to dehydration processes as the subducted lithospheric plate drags hydrated rocks from the Earth&apos;s surface downwards. Several competing hypotheses related to mineral dehydration or thermal processes explain the earthquakes at these depths yet need to be verified through earthquake parameters such as stress drop, rupture speed, or energy budget. However, traditional seismological analyses usually extract only average values, leaving the possible rupture complexity widely unexplored. In this study, we derive a rupture model of a 90 km deep Mw5.8 earthquake in the western part of the Hellenic subduction zone. The model is constrained by two independent methods using seismic recordings of the mainshock and an aftershock substituting the wave propagation between the source and stations. We find that the rupture started in a highly prestressed concentrated patch with fast velocity. Then it slowed down, but in the final stage, it broke another patch with a stress drop as high as 60 MPa, a value seldom found for crustal events. Deciphering the individual rupture episodes helps to distinguish the generating mechanism, indicating that the earthquake was triggered by dehydration processes related to rock compaction and stress transfer.

Název v anglickém jazyce

Complex Dynamic Rupture of an Mw5.8 Intermediate-Depth Earthquake in the Hellenic Slab

Popis výsledku anglicky

Earthquakes in the Hellenic slab, traced by tomography down to 1,200 km, occur at depths &lt;200 km with enigmatic origin and dynamics. We study a 2014 Mw5.8 left-lateral strike-slip earthquake originating at a depth of similar to 90 km under arc-parallel compression, featuring a small implosive component of the moment tensor. We use well-recorded aftershock as an empirical Green&apos;s function to infer reliable apparent source time functions up to 2 Hz. They exhibit multiple peaks with pronounced directivity and serve as input data to infer kinematic and dynamic rupture evolution in Bayesian source inversion. Our finite-fault kinematic and dynamic source models consistently reveal episodic behavior with two prominent asperities, short rupture duration, unilateral propagation, and locally high rupture speed and stress drop. We speculate the event was triggered and driven by dehydration and stress transfer associated with shear deformation and rock compaction. Plain Language Summary Intermediate-depth earthquakes (60-300 km) occur in subduction zones and their origin is often attributed to dehydration processes as the subducted lithospheric plate drags hydrated rocks from the Earth&apos;s surface downwards. Several competing hypotheses related to mineral dehydration or thermal processes explain the earthquakes at these depths yet need to be verified through earthquake parameters such as stress drop, rupture speed, or energy budget. However, traditional seismological analyses usually extract only average values, leaving the possible rupture complexity widely unexplored. In this study, we derive a rupture model of a 90 km deep Mw5.8 earthquake in the western part of the Hellenic subduction zone. The model is constrained by two independent methods using seismic recordings of the mainshock and an aftershock substituting the wave propagation between the source and stations. We find that the rupture started in a highly prestressed concentrated patch with fast velocity. Then it slowed down, but in the final stage, it broke another patch with a stress drop as high as 60 MPa, a value seldom found for crustal events. Deciphering the individual rupture episodes helps to distinguish the generating mechanism, indicating that the earthquake was triggered by dehydration processes related to rock compaction and stress transfer.

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

2025

Kód důvěrnosti údajů

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

Název periodika

Geophysical Research Letters

ISSN

0094-8276

e-ISSN

1944-8007

Svazek periodika

52

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

e2024GL113649

Kód UT WoS článku

001456506200001

EID výsledku v databázi Scopus

2-s2.0-105002051028