Accurate re-estimation of the Ms=6.2, June 15, 1995, Aigion (Greece) earthquake fault modeling
Panagiotis Elias(1), Pierre Briole(2) and Maya Ilieva(2)
(1) National Observatory of Athens, I. Metaxa & Vas. Pavlou, GR-15236 Penteli, Greece
(2) Ecole Normale Supérieure, 24 Rue Lhomond, 75005 Paris, France
Interferogram stacking is a common technique for atmospheric phase screen (APS) and other unwanted artifact minimisation that are not correlated in time. In the case of ground deformation produced by an earthquake, it can significantly reduce the noise and enhance the quality of a co-seismic deformation map, as has been demonstrated in the case of the September 17, 1999, Athens earthquake ([Elias et al., 2006]). In the present study this technique has been applied in order to improve the knowledge of the deformation pattern of the June 15, 1995, Aigion earthquake, and re-estimate its fault parameters with better accuracy than [Bernard et al., 1997]. Fourteen ERS1 and ERS2 scenes have been used. Fourteen co–seismic interferograms (having satisfactory baselines) have been calculated using ROI_PAC open source software. They have been unwrapped, corrected for orbital fringes, stacked and low pass filtered. By wrapping again and applying an edge detection filter the edges of the fringes revealed and precisely discriminated. The comparison between the edges of the fringes with the modeled deformation field leaded to accurate tuning of the modeled deformation parameters. In this work we assumed that the pre- and post-seismic deformation related to the earthquake were negligible, an assumption supported by the coordinates time series of GPS points measured every year around the epicenter area.
P. Bernard, P. Briole, B.Meyer, H. Lyon-Caen, J.-M. Gomez, C. Tiberi, C. Berge, R. Cattin, D. Hatzfeld, C. Lachet, B. Lebrun, A. Deschamps, F. Courboulex, C. Larroque, A. Rigo, D. Massonnet, P. Papadimitriou, J. Kassaras, D. Diagourtas, K. Makropoulos, G. Veis, E. Papazisi, C. Mitsakaki, V. Karakostas, E. Papadimitriou, D. Papanastassiou, M. Chouliaras & G. Stavrakakis. «The Ms=6.2, June 15, 1995 Aigion earthquake (Greece): evidence for low
angle normal faulting in the Corinth rift», Journal of Seismology, 1, pp. 131-150, 1997.
P. Elias , C. Kontoes, O. Sykioti, A. Avallone, S. Van Gorp, P. Briole, D. Paradissis. «A method for rapid elimination of high frequency signal noise and unwrapping artefacts from interferometric calculation». International Journal of Remote Sensing, Vol. 27, Issue 14, pp. 3079 - 3086, 2006.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,