MODERATE MAGNITUDE EARTHQUAKE SEQUENCES IN CENTRAL GREECE (FOR THE YEAR 2008)


Published: Jan 25, 2010
Keywords:
moment tensor slip distribution shake map seismicity Greece
Z. Roumelioti
A. Kiratzi
Abstract
The small-to-moderate magnitude earthquake sequences offshore NE Evia island (Mantoudi, October 2008) and in central Greece, to the NW of the town of Amfiklia (December 2008) are studied in terms of their source parameters and strong shaking in nearby populated areas. Moment tensors of the strongest events of the sequences, their seismogenic faults and the distribution of slip on them are sought through the inversion of regional broadband waveforms. We then apply a forward modelling technique, which incorporates synthetic Green’s functions calculated for a 1D velocity model, previously proposed for the broader studied area, to get a first-order evaluation of the distribution of strong ground shaking around the hypocenters. The Mantoudi earthquake sequence is found to be associated to an offshore NESW trending normal fault that dips to the NW, with a considerable dextral strike-slip component. The Amfiklia earthquake sequence is related to a pure normal, E-W trending fault which dips to the south. This conclusion is drawn by both the distribution of aftershocks and the inversion process for the computation of slip on the seismogenic fault of the strongest event of the sequence (Mw5.1). Forward modelling of strong ground shaking based on event-specific moment tensor and slip distribution indicates low levels of expected ground motion in accordance with the limited observed damage.
Article Details
  • Section
  • Seismology
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Author Biography
Z. Roumelioti
References
Benetatos C., Kiratzi A., Kementzetzidou K., Roumelioti Z., Karakaisis G., Scordilis E., Latoussakis I.
and Drakatos G., 2004. The Psachna (Evia Island) earthquake swarm of June 2003. Bulletin of the Geological
Society of Greece, XXXVI (3), 1379 - 1388.
Briole P., Rigo A., Lyon-Caen H., Ruegg J., Papazissi K., Mitsakaki C., Balodimou A., Veis G., Hatzfeld
D. and Deschamps, A. (2000). Active deformation of the Corinth rift, Greece: Results from repeated
Global Positioning System surveys between 1990 and 1995, J. Geophys. Res., 105(B11), 25605–
Clarke P. J., Davies R. R., England P. C., Parsons B., Billiris H., Paradissis D., Veis G., Cross P. A., Denys
P. H., Ashkenazi V., Bingley R., Kahle H.- G., Muller M.-V. and Briole, P. (1998). Crustal strain in
central Greece from repeated GPS measurements in the interval 1989–1997, Geophys. J. Int., 135(1),
–214, 1998.
Chouliaras G. (2009). Seismicity anomalies prior to the 13 December 2008, MS=5.7 earthquake in central
Greece, Nat. Hazards Earth Syst. Sci. 9, 501-506.
Dreger D. S., 2002. Time-Domain Moment Tensor INVerse Code (TDMT_INVC) Version 1.1. Berkeley
Seismological Laboratory, pp. 18.
Dreger D. S., 2003. TDMT_INV: Time Domain Seismic Moment Tensor INVersion. International Handbook
of Earthquake and Engineering Seismology, W. H. K. Lee, H. Kanamori, P. C. Jennings and C.
Kisslinger (eds.), Vol. B, pp. 1627.
Dreger, D. S., and Kaverina A., 2000. Seismic remote sensing for the earthquake source process and nearsource
strong shaking: a case study of the October 16, 1999 Hector Mine earthquake, Geophys. Res.
XLIII, No 4 – 2152
Lett. 27, pp. 1941–1944.
Ganas, A., and Papoulia I., (2000). High-resolution, digital mapping of the seismic haxard within the
Gulf of Evia rift, Central Greece using normal fault segments as line sources, Natural Hazards 22,
-223.
Hatzfeld, D., Ziazia, M., Kemenzetzidou, D., Hatzidimitriou, P., Panagiotopoulos, D., Makropoulos, K.,
Papadimitriou, P. and Deschamps, A., 1999. Microseismicity and focal mechanisms at the western termination
of the North Anatolian Fault and their implications for continental tectonics. Geophys. J. Int.,
, 891-908.
Kaverina A., Dreger D., and Price E., 2002. The Combined Inversion of Seismic and Geodetic Data for
the Source Process of the 16 October 1999 Mw 7.1 Hector Mine, California, Earthquake, Bull. Seism.
Soc. Am. 92, pp. 1266-1280.
Kiratzi A., 2002. Stress tensor inversions along the westernmost North Anatolian Fault Zone and its continuation
into the North Aegean Sea. Geophys. J. Int., 151, 360-376.
Novotný O., Zahradník J., and Tselentis G.-A., 2001. North-Western Turkey earthquakes and the crustal
structure inferred from surface waves observed in Western Greece. Bull. Seismol. Soc. Am., 91, pp.
-879.
Roberts G. P. and Ganas, A. (2000). Fault slip directions in central and southern Greece measured from
striated and conjugated fault planes: Comparison with focal mechanism and geodetic data, J. Geophys.
Res., 105, 23443–23462.
Roumelioti, Z., Benetatos, C., Kiratzi, A. and Dreger D., 2008a. Near-real time moment tensors for earthquakes
in Greece based on seismological data of the Hellenic Unified Seismological Network. 3rd National
Conference of Earthquake Engineering and Engineering Seismology, Athens, 5-7 November,
, paper ID:1789.
Roumelioti, Z., Kiratzi, A. and Dreger D., 2008b. Near-Real Time Shake Maps for Earthquakes in Greece:
pilot application. 3rd National Conference of Earthquake Engineering and Engineering Seismology,
Athens, 5-7 November, 2008, paper ID: 2105.
Roumelioti, Z., Kiratzi A. and Benetatos Ch. (2010). Time domain moment tensors of earthquakes in
Greece and its surroundings for the years 2006-2007: the database of the Aristotle University of Thessaloniki,
Journal of Geodynamics, in press.
Saikia C. K., 1994. Modified frequency-wavenumber algorithm for regional seismograms using Filon’s
quadrature; modeling of Lg waves in eastern North America. Geophys. Journ. Int., 118, pp. 142-158.
Skarlatoudis, A. A., Papazachos C. B., Margaris B. N., Theodulidis N., Papaioannou Ch., Kalogeras I.,
Scordilis E. M., and Karakostas V., 2003. Empirical peak ground-motion predictive relations for shallow
earthquakes in Greece. Bull. Seism. Soc. Am. 93, pp. 2591-2603.
Skarlatoudis, A. A., Papazachos C. B., Margaris B. N., Theodulidis N., Papaioannou Ch., Kalogeras I.,
Scordilis E. M., and Karakostas V., 2007. Erratum to “Empirical peak ground-motion predictive relations
for shallow earthquakes in Greece. Bull. Seism. Soc. Am. 97(6), pp. 2219-2221, doi:
1785/0120070176.
Wald, D. J., and Allen T. I., 2007. Topographic slope as a proxy for seismic site conditions and amplification.
Bull. Seism. Soc. Am. 97(5), pp. 1379-1395, doi: 10.1785/ 0120060267.
Wessel, P., and Smith, W.H.F., 1998. New improved version of the Generic Mapping Tools released. EOS
Trans. AGU 79, 579.
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