Probing the northern Chile megathrust with seismicity: The 2014 M8.1 Iquique earthquake sequence

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F19%3A00522087" target="_blank" >RIV/67985530:_____/19:00522087 - isvavai.cz</a>

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JB017794" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JB017794</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2019JB017794" target="_blank" >10.1029/2019JB017794</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Probing the northern Chile megathrust with seismicity: The 2014 M8.1 Iquique earthquake sequence

Popis výsledku v původním jazyce

We used data from >100 permanent and temporary seismic stations to investigate seismicity patterns related to the 1 April 2014 M8.1 Iquique earthquake in northern Chile. Applying a multistage automatic event location procedure to the seismic data, we detected and located 19,000 foreshocks, aftershocks, and background seismicity for 1 month preceding and 9 months following the mainshock. Foreshocks skirt around the updip limit of the mainshock asperity, aftershocks occur mainly in two belts updip and downdip of it. The updip seismicity primarily locates in a zone of transitional friction on the megathrust and can be explained by preseismic stress loading due to slow-slip processes and afterslip driven by increased Coulomb failure stress due to the mainshock and its largest aftershock. Afterslip further south also triggered aftershocks and repeating earthquakes in several EW striking streaks. We interpret the streaks as markers of surrounding creep that could indicate a change in fault mechanics and may have structural origin, caused by fluid-induced failure along presumed megathrust corrugations. Megathrust aftershocks terminate updip below the seaward frontal prism in the outer continental wedge that probably behaves aseismically under velocity-strengthening conditions. The inner wedge locates further landward overlying the megathrust's seismogenic zone. Further downdip, aftershocks anticorrelate with the two major afterslip patches resolved geodetically and partially correlate with increased Coulomb failure stress, overall indicating heterogeneous frictional behavior. A region of sparse seismicity at 40- to 50-km depth is followed by the deepest plate interface aftershocks at 55- to 65-km depth, which occur in two clusters of significantly different dip.

Název v anglickém jazyce

Probing the northern Chile megathrust with seismicity: The 2014 M8.1 Iquique earthquake sequence

Popis výsledku anglicky

We used data from >100 permanent and temporary seismic stations to investigate seismicity patterns related to the 1 April 2014 M8.1 Iquique earthquake in northern Chile. Applying a multistage automatic event location procedure to the seismic data, we detected and located 19,000 foreshocks, aftershocks, and background seismicity for 1 month preceding and 9 months following the mainshock. Foreshocks skirt around the updip limit of the mainshock asperity, aftershocks occur mainly in two belts updip and downdip of it. The updip seismicity primarily locates in a zone of transitional friction on the megathrust and can be explained by preseismic stress loading due to slow-slip processes and afterslip driven by increased Coulomb failure stress due to the mainshock and its largest aftershock. Afterslip further south also triggered aftershocks and repeating earthquakes in several EW striking streaks. We interpret the streaks as markers of surrounding creep that could indicate a change in fault mechanics and may have structural origin, caused by fluid-induced failure along presumed megathrust corrugations. Megathrust aftershocks terminate updip below the seaward frontal prism in the outer continental wedge that probably behaves aseismically under velocity-strengthening conditions. The inner wedge locates further landward overlying the megathrust's seismogenic zone. Further downdip, aftershocks anticorrelate with the two major afterslip patches resolved geodetically and partially correlate with increased Coulomb failure stress, overall indicating heterogeneous frictional behavior. A region of sparse seismicity at 40- to 50-km depth is followed by the deepest plate interface aftershocks at 55- to 65-km depth, which occur in two clusters of significantly different dip.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

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

—

Svazek periodika

124

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

20

Strana od-do

12935-12954

Kód UT WoS článku

000500672800001

EID výsledku v databázi Scopus

2-s2.0-85076136558