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| Titel |
Static Stress Changes Inverted from Microseismicity in Eastern Aegean Sea |
| VerfasserIn |
Konstantinos Leptokaropoulos, Eleftheria Papadimitriou, Beata Orlecka-Sikora, Vassilios Karakostas |
| 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 |
250094921
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| Publikation (Nr.) |
 EGU/EGU2014-10356.pdf |
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| Zusammenfassung |
| In this study we attempted to derive static stress field variations from the changes of
earthquake production rates in Kusadasi bay and Samos island (eastern Aegean), by applying
the Dieterich et al. (2000) Rate/State formulation. The calculation of stress changes from
earthquake occurrence rates fluctuations should be obtained from catalogues which achieve
adequate spatial and temporal resolution and well determined hypocenter coordinates. For
this reason we took advantage of the data from a regional network operating since July of
2007, providing continuous monitoring of microseismicity, along with data available from
seismological stations of the permanent Hellenic Unified Seismological Network (HUSN).
The high accuracy and large sized regional catalogue is utilized for inverting seismicity rate
changes into stress variation through a Rate/State dependent friction model. After
explicitly determining the physical parameters incorporating in the modeling (reference
seismicity rates, characteristic relaxation time, constitutive properties of fault zones)
we investigated stress changes in both space and time regime and their possible
connection with earthquake clustering and fault interactions. The main interest is
focused on the June 2009 Samos Mw=5.1 event, which was followed by an intense
seismic activity for several days. We attempt to reproduce and interpret stress changes
both before and after the initiation of this seismic burst. The differences between
the earthquake occurrence rates before and after the main shock are used as input
data in a stress inversion algorithm based upon the Rate/State dependent friction
concept in order to provide an estimation of stress changes. Diverse assumptions and
combinations of the parameters values are tested for the model performance and
sensitivity to be evaluated. The approach followed here could provide evidence of the
robustness of the seismicity rate changes usage as a stress meter for both positive and
negative stress steps in an actively tectonic region accommodating complex fault
systems.
Acknowledgements: Support from the bilateral agreement between Aristotle University
of Thessaloniki and Institute of Geophysics of Polish Academy of Sciences during August
2013 and the research project titled as “Seismotectonic properties of the eastern Aegean:
Implications on the stress field evolution and seismic hazard assessment in a tectonically
complex area”, GSRT 10 T UR/1–3–9, Joint Research and Technology Programmes
2010–2011, financed by the Ministry of Education of Greece and the Scientific and
Technological Research Council of Turkey (TUBITAK 109Y401) are acknowledged. |
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