Combined Inversion of broadband and short-period waveform data for regional moment tensors: A case study in the Alborz Mountains, Iran
- In this study, we suggest a novel approach for the retrieval of regional moment tensors for earthquakes with small to moderate magnitudes. The first modification is the combined inversion of broadband and short-period waveform data. The broadband waveforms are inverted in a frequency range suitable for surface waves, whereas for the short-period data a frequency range suitable for body waves is applied. The second modification is the use of first-motion body-wave polarities to select the most probable solution out of all solutions from inversion. To combine three different criteria for selecting the most probable solution (i.e., residual from inversion, double-couple content of solution, number of nonmatching first-motion body-wave polarities), the L2 norm is applied to the normalized parameters. We chose five earthquakes within the Alborz mountains, Iran, as a case study (3.1 <= M-w <= 4.1). In this area, several factors exacerbate the difficulty of performing inversion for moment tensors, for example, a heterogeneous station networkIn this study, we suggest a novel approach for the retrieval of regional moment tensors for earthquakes with small to moderate magnitudes. The first modification is the combined inversion of broadband and short-period waveform data. The broadband waveforms are inverted in a frequency range suitable for surface waves, whereas for the short-period data a frequency range suitable for body waves is applied. The second modification is the use of first-motion body-wave polarities to select the most probable solution out of all solutions from inversion. To combine three different criteria for selecting the most probable solution (i.e., residual from inversion, double-couple content of solution, number of nonmatching first-motion body-wave polarities), the L2 norm is applied to the normalized parameters. We chose five earthquakes within the Alborz mountains, Iran, as a case study (3.1 <= M-w <= 4.1). In this area, several factors exacerbate the difficulty of performing inversion for moment tensors, for example, a heterogeneous station network and large azimuthal gaps. We have demonstrated that our approach supplies reliable moment tensors when inversion from broadband data alone fails. In one case, we successfully retrieved a stable solution from short-period waveform data alone. Thus, our approach enables successful determination of seismic moment tensors wherever a sparse network of broadband stations has thus far prevented it.…
Verfasserangaben: | Stefanie DonnerORCiD, Frank KrügerGND, Dirk Roessler, Abdolreza Ghods |
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DOI: | https://doi.org/10.1785/0120130229 |
ISSN: | 0037-1106 |
ISSN: | 1943-3573 |
Titel des übergeordneten Werks (Englisch): | Bulletin of the Seismological Society of America |
Verlag: | Seismological Society of America |
Verlagsort: | Albany |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2014 |
Erscheinungsjahr: | 2014 |
Datum der Freischaltung: | 27.03.2017 |
Band: | 104 |
Ausgabe: | 3 |
Seitenanzahl: | 16 |
Erste Seite: | 1358 |
Letzte Seite: | 1373 |
Fördernde Institution: | German Research Council (DFG Project) [KR 1935/12-1]; DFG Leibniz Award [373/20-1]; Iranian Institute of Earthquake Engineering and Seismology (IIEES); Institute of Geophysics, University of Tehran (IGUT) |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer Review: | Referiert |
Name der Einrichtung zum Zeitpunkt der Publikation: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |