Moment Tensor inversion based on the principal component analysis of waveforms: Method and application to microearthquakes in West Bohemia, Czech Republic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F17%3A00479173" target="_blank" >RIV/67985530:_____/17:00479173 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1785/0220170027" target="_blank" >http://dx.doi.org/10.1785/0220170027</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1785/0220170027" target="_blank" >10.1785/0220170027</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Moment Tensor inversion based on the principal component analysis of waveforms: Method and application to microearthquakes in West Bohemia, Czech Republic

Popis výsledku v původním jazyce

We develop and test a new hybrid approach of the amplitude and waveform moment tensor inversions, which utilizes the principal component analysis of seismograms. The proposed inversion is less sensitive to noise in data, being thus more accurate and more robust than the amplitude inversion. It also suppresses other unmodeled phenomena, like a directivity of the source, errors caused by local site effects at individual stations, and by time shifts in arrivals of observed and synthetic signals due to an inaccurate velocity model. This inversion is computationally less demanding than the full waveform inversion and thus applicable to large sets of earthquakes. The approach is numerically tested on synthetic data with various levels of noise. The applicability of the inversion is demonstrated on inverting more than 800 microearthquakes that occurred during the 2014 activity in West Bohemia, Czech Republic. The analysis revealed several distinct clusters of moment tensors. Focal mechanisms corresponding to moment tensors of three clusters are left-lateral strike slips associated with the most active fault in the focal zone. Another cluster is characterized by right-lateral strike slips associated with the fault conjugate to the main fault. Finally, we identified a cluster with pure reverse focal mechanisms that are anomalous and not expected to occur in the region. These mechanisms were not detected in previous seismic activity, and they have an unfavorable orientation with respect to regional tectonic stress. This might indicate a presence of local stress heterogeneities caused, for example, by an interaction of faults or fault segments in the focal zone.

Název v anglickém jazyce

Moment Tensor inversion based on the principal component analysis of waveforms: Method and application to microearthquakes in West Bohemia, Czech Republic

Popis výsledku anglicky

We develop and test a new hybrid approach of the amplitude and waveform moment tensor inversions, which utilizes the principal component analysis of seismograms. The proposed inversion is less sensitive to noise in data, being thus more accurate and more robust than the amplitude inversion. It also suppresses other unmodeled phenomena, like a directivity of the source, errors caused by local site effects at individual stations, and by time shifts in arrivals of observed and synthetic signals due to an inaccurate velocity model. This inversion is computationally less demanding than the full waveform inversion and thus applicable to large sets of earthquakes. The approach is numerically tested on synthetic data with various levels of noise. The applicability of the inversion is demonstrated on inverting more than 800 microearthquakes that occurred during the 2014 activity in West Bohemia, Czech Republic. The analysis revealed several distinct clusters of moment tensors. Focal mechanisms corresponding to moment tensors of three clusters are left-lateral strike slips associated with the most active fault in the focal zone. Another cluster is characterized by right-lateral strike slips associated with the fault conjugate to the main fault. Finally, we identified a cluster with pure reverse focal mechanisms that are anomalous and not expected to occur in the region. These mechanisms were not detected in previous seismic activity, and they have an unfavorable orientation with respect to regional tectonic stress. This might indicate a presence of local stress heterogeneities caused, for example, by an interaction of faults or fault segments in the focal zone.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

<a href="/cs/project/GC16-19751J" target="_blank" >GC16-19751J: Určení seismické anizotropie a útlumu z akustických emisí a pozorování přirozené a indukované seismicity</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Seismological Research Letters

ISSN

0895-0695

e-ISSN

—

Svazek periodika

88

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

18

Strana od-do

1303-1315

Kód UT WoS článku

000416129000011

EID výsledku v databázi Scopus

2-s2.0-85028312124