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| Titel |
A homogeneous earthquake catalogue of relocated recent shallow events of the Hellenic arc |
| VerfasserIn |
Maria Kolligri, Emmanuel Scordilis, Stelios Koutrakis, Christos Evangelidis, Constantinos Papazachos, George Karakaisis, George Drakatos, Filippos Vallianatos |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250097901
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| Publikation (Nr.) |
 EGU/EGU2014-13527.pdf |
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| Zusammenfassung |
| The aim of this study is the compilation of a new homogeneous (with respect to magnitude)
catalogue for shallow (h3.0 were considered, resulting in the
generation of a unified data-base with phase readings from 13535 earthquakes. Three location
algorithms were used for the initial relocation procedure, namely the HYPO71 earthquake
location program (Lee & Lahr, 1972), the HYPOINVERSE algorithm (Klein, 2002) and
the double-difference algorithm, HYPODD (Waldhauser & Ellsworth, 2000). The
phase data were initially processed with both absolute location algorithms, namely
HYPO71 and HYPOINVERSE algorithm, using the velocity model proposed by
Karagianni et al. (2005). This relocation procedure resulted in an updated dataset
12149 earthquakes, for which improved relocations could be provided. The final
relocation was performed by applying the double-difference algorithm, HYPODD,
using the velocity model proposed for the study area by Karagianni et al. (2002), as
it was considered as the more representative. The above procedure allowed the
relocation of 8117 earthquakes revealing, in some cases, significant differences in
both the depths and the epicenters of these earthquakes, with respect to the initial
(HYPO71-HYPOINVERSE) catalogue. Several reports on the magnitudes of the
earthquakes of the catalogue were elaborated in order to obtain the most reliable
magnitude approximation. The available estimates, derived from several centers,
include magnitude values expressed in several magnitude scales. Considering the
moment-magnitude scale as the most reliable one, the values of the reported magnitudes of
each earthquake were converted to the respective moment magnitudes by using already
published converting relations (Papazachos et al., 2002; Scordilis, 2006) and their
weighted mean value (inversely proportional to the standard error of each calibrating
relation) was taken as the moment magnitude of this earthquake. When original
moment magnitudes were available, their values were adopted without any additional
processing. The revised catalogue revealed a more detailed picture of the seismicity of the
Hellenic Arc, allowing the identification of specific earthquake clusters and better
describing the faulting structures of this seismotectonically very active and high-hazard
area.
This research has been funded by the European Union (European Social Fund) and Greek
national resources under the framework of the “THALES Program: SEISMO FEAR
HELLARC” project of the “Education & Lifelong Learning” Operational Programme. |
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