Deep-Focus Earthquakes Under Northeast China-An Imprint of the Complex Tectonic History of Pacific Plate Subduction

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10508353" target="_blank" >RIV/00216208:11320/25:10508353 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=lEJIskgO2v" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=lEJIskgO2v</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2024JB030215" target="_blank" >10.1029/2024JB030215</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Deep-Focus Earthquakes Under Northeast China-An Imprint of the Complex Tectonic History of Pacific Plate Subduction

Popis výsledku v původním jazyce

Deep-focus earthquakes and their association with metastable olivine wedges (MOWs) remain enigmatic. Here we perform a seismic-geodynamic analysis of the Pacific slab stagnant at the 660 km deep bottom of the mantle transition zone. All investigated deep earthquakes exhibit only minor (mostly implosive) isotropic components, yet exhibit strongly varying compensated-linear-vector-dipole components. For the largest studied earthquake (M W 6.9), we demonstrate a significant stress-drop heterogeneity on a subhorizontal fault and a spatial change in radiation efficiency. We interpret the earthquakes with an evolutionary numerical subduction model with realistic mineralogy and rheology, including non-uniform plate aging and subduction disruption due to the Izanagi-Pacific ridge sinking in the early Cenozoic. This process resulted in a present-day tomography-supported bent slab, preserving low temperatures (900-1000 K), which permits the metastable olivine presence. Further, we demonstrate that the potential MOW is also bent. The accompanying internal deformation controls the deep seismicity in the slab tip with apparent changes in seismic radiation efficiency and rupture speed across the modeled temperature gradients. From a broader perspective, the MOW contortion may contribute to deformational anisotropy in the shallow lower mantle. Our results underscore the importance of joint interpretations of the evolutionary subduction models and seismic source inversions.

Název v anglickém jazyce

Deep-Focus Earthquakes Under Northeast China-An Imprint of the Complex Tectonic History of Pacific Plate Subduction

Popis výsledku anglicky

Deep-focus earthquakes and their association with metastable olivine wedges (MOWs) remain enigmatic. Here we perform a seismic-geodynamic analysis of the Pacific slab stagnant at the 660 km deep bottom of the mantle transition zone. All investigated deep earthquakes exhibit only minor (mostly implosive) isotropic components, yet exhibit strongly varying compensated-linear-vector-dipole components. For the largest studied earthquake (M W 6.9), we demonstrate a significant stress-drop heterogeneity on a subhorizontal fault and a spatial change in radiation efficiency. We interpret the earthquakes with an evolutionary numerical subduction model with realistic mineralogy and rheology, including non-uniform plate aging and subduction disruption due to the Izanagi-Pacific ridge sinking in the early Cenozoic. This process resulted in a present-day tomography-supported bent slab, preserving low temperatures (900-1000 K), which permits the metastable olivine presence. Further, we demonstrate that the potential MOW is also bent. The accompanying internal deformation controls the deep seismicity in the slab tip with apparent changes in seismic radiation efficiency and rupture speed across the modeled temperature gradients. From a broader perspective, the MOW contortion may contribute to deformational anisotropy in the shallow lower mantle. Our results underscore the importance of joint interpretations of the evolutionary subduction models and seismic source inversions.

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/LUAUS23233" target="_blank" >LUAUS23233: Dynamika subdukčních desek a původ zemětřesení s hlubokým ohniskem</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

Journal of Geophysical Research: Solid Earth

ISSN

2169-9313

e-ISSN

2169-9356

Svazek periodika

130

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

18

Strana od-do

e2024JB030215

Kód UT WoS článku

001563634800001

EID výsledku v databázi Scopus

2-s2.0-105014880695