Empirical Evidence of Frequency-Dependent Directivity Effects From Small-To-Moderate Normal Fault Earthquakes in Central Italy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10452078" target="_blank" >RIV/00216208:11320/22:10452078 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=m.GV6Quwl5" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=m.GV6Quwl5</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2021JB023498" target="_blank" >10.1029/2021JB023498</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Empirical Evidence of Frequency-Dependent Directivity Effects From Small-To-Moderate Normal Fault Earthquakes in Central Italy

Popis výsledku v původním jazyce

Rupture directivity and its potential frequency dependence is an open issue within the seismological community, especially for small-to-moderate events. Here, we provide a statistical overview based on empirical evidence of seismological observations, thanks to the large amount of high-quality seismic recordings (more than 30,000 waveforms) from Central Italy, which represents an excellent and almost unique natural laboratory of normal faulting earthquakes in the magnitude range between 3.4 and 6.5 within the time frame 2008-2018. In order to detect an anisotropic distribution of ground motion amplitudes due to the rupture directivity, we fit the smoothed Fourier Amplitude Spectra (FAS) cleared of source-, site- and path-effects. According to our criteria, about 36% of the analyzed events (162 out of 456) are directive and the distribution of rupture direction is aligned with the strikes of the major faults of the Central Apennines. We find that the directivity is a band-limited phenomenon whose width may extend up to five times the corner frequency. The results of this research provide useful insights to parameterize directivity, to be explicitly implemented in future ground motion modeling and scenario predictions.

Název v anglickém jazyce

Empirical Evidence of Frequency-Dependent Directivity Effects From Small-To-Moderate Normal Fault Earthquakes in Central Italy

Popis výsledku anglicky

Rupture directivity and its potential frequency dependence is an open issue within the seismological community, especially for small-to-moderate events. Here, we provide a statistical overview based on empirical evidence of seismological observations, thanks to the large amount of high-quality seismic recordings (more than 30,000 waveforms) from Central Italy, which represents an excellent and almost unique natural laboratory of normal faulting earthquakes in the magnitude range between 3.4 and 6.5 within the time frame 2008-2018. In order to detect an anisotropic distribution of ground motion amplitudes due to the rupture directivity, we fit the smoothed Fourier Amplitude Spectra (FAS) cleared of source-, site- and path-effects. According to our criteria, about 36% of the analyzed events (162 out of 456) are directive and the distribution of rupture direction is aligned with the strikes of the major faults of the Central Apennines. We find that the directivity is a band-limited phenomenon whose width may extend up to five times the corner frequency. The results of this research provide useful insights to parameterize directivity, to be explicitly implemented in future ground motion modeling and scenario predictions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10500 - Earth and related environmental sciences

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

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

2169-9356

Svazek periodika

127

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

24

Strana od-do

e2021JB023498

Kód UT WoS článku

000813541300001

EID výsledku v databázi Scopus

2-s2.0-85132874152