Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10366885" target="_blank" >RIV/00216208:11320/17:10366885 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1186/s40623-017-0721-4" target="_blank" >http://dx.doi.org/10.1186/s40623-017-0721-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1186/s40623-017-0721-4" target="_blank" >10.1186/s40623-017-0721-4</a>

Result language

angličtina

Original language name

Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

Original language description

On April 16, 2016, Kumamoto prefecture in Kyushu region, Japan, was devastated by a shallow MJMA7.3 earthquake. The series of foreshocks started by MJMA6.5 foreshock 28 h before the mainshock. They have originated in Hinagu fault zone intersecting the mainshock Futagawa fault zone; hence, the tectonic background for this earthquake sequence is rather complex. Here we infer centroid moment tensors (CMTs) for 11 events with MJMA between 4.8 and 6.5, using strong motion records of the K-NET, KiK-net and F-net networks. We use upgraded Bayesian full-waveform inversion code ISOLA-ObsPy, which takes into account uncertainty of the velocity model. Such an approach allows us to reliably assess uncertainty of the CMT parameters including the centroid position. The solutions show significant systematic spatial and temporal variations throughout the sequence. Foreshocks are right-lateral steeply dipping strike-slip events connected to the NE-SW shear zone. Those located close to the intersection of the Hinagu and Futagawa fault zones are dipping slightly to ESE, while those in the southern area are dipping to WNW. Contrarily, aftershocks are mostly normal dip-slip events, being related to the N-S extensional tectonic regime. Most of the deviatoric moment tensors contain only minor CLVD component, which can be attributed to the velocity model uncertainty. Nevertheless, two of the CMTs involve a significant CLVD component, which may reflect complex rupture process. Decomposition of those moment tensors into two pure shear moment tensors suggests combined right-lateral strike-slip and normal dip-slip mechanisms, consistent with the tectonic settings of the intersection of the Hinagu and Futagawa fault zones.

Czech name

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Czech description

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Type

J_imp - 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

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2017

Confidentiality

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

Name of the periodical

EARTH PLANETS AND SPACE

ISSN

1880-5981

e-ISSN

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Volume of the periodical

69

Issue of the periodical within the volume

September

Country of publishing house

DE - GERMANY

Number of pages

19

Pages from-to

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UT code for WoS article

000411750200001

EID of the result in the Scopus database

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