Detection of stress anomaly produced by interaction of compressive fault steps in the West Bohemia swarm region, Czech Republic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F18%3A00495199" target="_blank" >RIV/67985530:_____/18:00495199 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1029/2018TC005163" target="_blank" >http://dx.doi.org/10.1029/2018TC005163</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2018TC005163" target="_blank" >10.1029/2018TC005163</a>

Result language

angličtina

Original language name

Detection of stress anomaly produced by interaction of compressive fault steps in the West Bohemia swarm region, Czech Republic

Original language description

Observations of the 2008-2014 seismic activity in West Bohemia, Czech Republic, provide evidence of interaction of compressive fault steps that created local stress anomaly and triggered a seismic sequence with exceptional properties. The West Bohemia is a geothermal area, characterized by persistent fluid-driven seismicity in the form of earthquake swarms. The focal zone is formed by two weak and fluid-eroded parallel strike-slip faults with a step of about 200m. The fault segments were activated successively by the 2008 and 2011 swarms with magnitudes of the strongest events of 3.8 and 3.7, respectively. In 2014, a fracture linking both segments was formed or activated by a mainshock-aftershock sequence. The aftershock decay was very fast, and the focal mechanism of the strongest event with magnitude of 4.2 was inconsistent with the regional background stress. The stress inversion of 957 focal mechanisms revealed a stress anomaly characterized by interchanging the sigma(2) and sigma(3) principal stress axes in the area of fault interaction. The modeling of the Coulomb stress change confirmed that the stress anomaly could completely disturb the regional background stress and produce the rotation of the principal stress axes retrieved from focal mechanisms. The faults activated or newly formed within the compressive stress anomaly were of high strength, which caused the anomalous mainshock-aftershock character of the 2014 activity and the rapid aftershock decay. Linking the two previously active isolated faults during the 2014 activity increased the expected moment magnitude M-w of a possible strongest earthquake from 5.0 to 5.4.

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

10507 - Volcanology

Project

<a href="/en/project/GC16-19751J" target="_blank" >GC16-19751J: Seismic anisotropy and attenuation retrieved from acoustic emissions and observations of natural and induced seismicity</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

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

Name of the periodical

Tectonics

ISSN

0278-7407

e-ISSN

—

Volume of the periodical

37

Issue of the periodical within the volume

11

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

4212-4225

UT code for WoS article

000453542200007

EID of the result in the Scopus database

2-s2.0-85056790781