2D stress rotation in the Tonga subduction region
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10473623" target="_blank" >RIV/00216208:11320/23:10473623 - isvavai.cz</a>
Výsledek na webu
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IsoxGLVyVE" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IsoxGLVyVE</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.epsl.2023.118379" target="_blank" >10.1016/j.epsl.2023.118379</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
2D stress rotation in the Tonga subduction region
Popis výsledku v původním jazyce
Despite their enigmatic origins, deep earthquakes provide unique information about the stress distribution in slabs. Down-dip compression is expected at depth, due to resistance from endothermic phase transition near 660 km and increasing viscosity. Focal mechanisms for ordinary deep (620-680 km) earthquakes in the Tonga subduction zone exhibit down-dip compressional stresses in agreement with this expectation, but unusually deep (>= 680 km) earthquakes exhibit vertical tension and horizontal compression. Here we present a numerical modelling study of the Tonga slab focused on stress patterns in the transition zone. The subducting Pacific plate is one of the oldest and thus coldest plates in the world, so our parametric study tests the effects of rheology and phase transitions on stress evolution for an exceptionally cold subducting plate. Our results suggest that direct buoyancy effects from the endothermic phase transition at 660 km depth are overprinted by bending-related forces. A stress pattern best fitting seismogenic stresses is found for the coldest tested subducting plate (150 Myr old) and a viscosity interface decoupled from the 660-km phase transition and shifted to 1000-km depth. An abrupt change of stress orientations is observed when the slab, temporarily deflected by the phase transition, penetrates to the shallow lower mantle and the fold of the flat-lying part is tightening. (c) 2023 Elsevier B.V. All rights reserved.
Název v anglickém jazyce
2D stress rotation in the Tonga subduction region
Popis výsledku anglicky
Despite their enigmatic origins, deep earthquakes provide unique information about the stress distribution in slabs. Down-dip compression is expected at depth, due to resistance from endothermic phase transition near 660 km and increasing viscosity. Focal mechanisms for ordinary deep (620-680 km) earthquakes in the Tonga subduction zone exhibit down-dip compressional stresses in agreement with this expectation, but unusually deep (>= 680 km) earthquakes exhibit vertical tension and horizontal compression. Here we present a numerical modelling study of the Tonga slab focused on stress patterns in the transition zone. The subducting Pacific plate is one of the oldest and thus coldest plates in the world, so our parametric study tests the effects of rheology and phase transitions on stress evolution for an exceptionally cold subducting plate. Our results suggest that direct buoyancy effects from the endothermic phase transition at 660 km depth are overprinted by bending-related forces. A stress pattern best fitting seismogenic stresses is found for the coldest tested subducting plate (150 Myr old) and a viscosity interface decoupled from the 660-km phase transition and shifted to 1000-km depth. An abrupt change of stress orientations is observed when the slab, temporarily deflected by the phase transition, penetrates to the shallow lower mantle and the fold of the flat-lying part is tightening. (c) 2023 Elsevier B.V. All rights reserved.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10500 - Earth and related environmental sciences
Návaznosti výsledku
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)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Ostatní
Rok uplatnění
2023
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Earth and Planetary Science Letters
ISSN
0012-821X
e-ISSN
1385-013X
Svazek periodika
621
Číslo periodika v rámci svazku
September
Stát vydavatele periodika
NL - Nizozemsko
Počet stran výsledku
12
Strana od-do
118379
Kód UT WoS článku
001084314000001
EID výsledku v databázi Scopus
2-s2.0-85172379660