National Technical University of Athens Higher Geodesy Laboratory
National Technical University of Athens Higher Geodesy Laboratory Dionysos Satellite Observatory Analysis of the Ms=6. 2, June 15, 1995 Aigion earthquake(Greece) : Data, products and preliminary results S. Alatza, P. Elias, P. Briole, D. Paradissis CRL School. CRL 2017, 22 -26 September 1
1. Study motivation/objectives Study area of great tectonic interest Re-analysis of the Ms=6. 2, June 15, 1995 Aigion earthquake New approach with SNAP Comparison with previous studies(Bernard et al. , 1997) Evaluation of SNAP benefits 2
2. Tectonic framework 2. 1 Major earthquakes 1965 -1995 3 Courtesy of [ Armijo et al. (1996) and major earthquakes since 1965 (1965, 1970: Baker et al. , (1997); 1981, 1984: Taymaz (1990); 1992: location from the present study, mechanism from Hatzfeld et al. (1996); 1995 earthquake: Bernard et al. , (1997). ]
2. 2 The 1995 Aigion earthquake Ms=6. 2 26 casualties Severe damages in Aigion city (2000 buildings) Courtesy of [ Bernard et al. , (1997). ] Aftershocks of the 1995 Aigion earthquake. 4
3. Data ERS level 1 images from the ESA Ascending track 415 Descending track 279 SRTM 3 -DEM 5
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4. Processing with SNAP 8
4. 1 Ιnterferometric pairs selection Descending Track Ascending Track 9
4. 2 Overview of ERS sensor C band 35 m spatial resolution 23 o look angle 100 km swath 35 day repeat 10
4. 3 Coregistration Different Coarse Window Width and Height in coarse coregistration 64 128 32 1024 11
4. 4 Coherence estimation Different ratio in range-azimuth window size 1 -5 2 -10 4 -20 12
4. 5 Coherence statistics 3600 vs 10000 GCP 13
10000 GCP 3600 GCP 14
5. Results 15
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6. Comparison with previous study April 29, 1995 -July 8, 1995 Altitude ambiguity 130 m Courtesy of [ Bernard et al. , (1997). ] Ten visible fringes around Psaromyta cape
6. Conclusions-Future work Slight difference between interferograms of ascending and descending track Nine visible fringes around Psaromyta cape with each fringe corresponding to 28 mm of ground deformation in the line of sight SNAP proved to be a high accuracy free software, compared with commercial software used in the past for the same seismic event 23
Combination of both tracks for the earthquake analysis Modelling of the earthquake using an inversion method Generation of all available co-seismic interferogarms to create an average stack Similar investigation was performed for Envisat images 24
Thank you! 25
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