Seismotectonics of the 2018 northern Osaka M6.1 earthquake and its aftershocks: joint movements on strike-slip and reverse faults in inland Japan
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10404666" target="_blank" >RIV/00216208:11320/19:10404666 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jxNV9NhQ-f" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jxNV9NhQ-f</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1186/s40623-019-1016-8" target="_blank" >10.1186/s40623-019-1016-8</a>
Alternative languages
Result language
angličtina
Original language name
Seismotectonics of the 2018 northern Osaka M6.1 earthquake and its aftershocks: joint movements on strike-slip and reverse faults in inland Japan
Original language description
On June 18, 2018, an M(JMA)6.1 inland crustal earthquake occurred on the northeast edge of the Osaka basin, Japan. This event impacted the region by the maximum PGA larger than 0.9g, and it was followed by a series of weaker aftershocks. The earthquakes were located near the Arima-Takatsuki Tectonic Line (ENE-WSW dextral strike-slip faults) and the Uemachi fault system (N-S reverse faults), hence the seismotectonic interpretations we assumed to be rather complex. Here we propose a seismotectonic model of this sequence based on seismological data and stress field considerations. In particular, we infer to a centroid moment tensor for the mainshock using Bayesian full-waveform inversion from strong motion records. The solution of M(w)5.6 involved a significant CLVD component, which we interpreted as being due to rupture process on a complex fault geometry. Decomposition of the non-DC moment tensor into major and minor pure-shear moment tensors suggests a combination of strike-slip and reverse faulting mechanisms. We also analyzed the 108 strongest aftershocks with M-JMA between 2.0 and 4.1 using records from broadband and short-period stations. Aftershocks' moment tensors inverted from P-wave amplitudes exhibit mainly strike-slip and reverse faulting mechanisms, having significant spatial variations. The local stress field inverted from these mechanisms had a dominant maximum (compressional) principal stress sigma(1) in ESE-WNW direction, while sigma(2)sigma(3). Both ENE-WSW dextral strike-slip and N-S reverse faults can be active in such stress field as observed in the mainshock (without any need for stress spatial inhomogeneity). To conclude, the activated strike-slip fault is parallel to the Arima-Takatsuki Tectonic Line. The activated N-S reverse fault is dipping to east by 50 degrees similarly as the Uemachi fault system. Joint shear movements on both of these faults contributed significantly to the total seismic moment of the mainshock.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10500 - Earth and related environmental sciences
Result continuities
Project
<a href="/en/project/GC18-06716J" target="_blank" >GC18-06716J: BAIES - Bayesian Inference of Earthquake Source parameters: kinematic and dynamic finite fault models</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
EARTH PLANETS AND SPACE
ISSN
1880-5981
e-ISSN
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Volume of the periodical
71
Issue of the periodical within the volume
2019
Country of publishing house
DE - GERMANY
Number of pages
21
Pages from-to
34
UT code for WoS article
000462920200001
EID of the result in the Scopus database
2-s2.0-85063609087