Measuring Interseismic Deformation Across The North Anatolian Fault: Comparison of InSAR techniques
Abstract
The challenge of measuring interseismic deformation across major active faults is to be able to measure small displacement rates at large spatial scale; typically, 1 cm/year or less distributed over 100 km or greater. Using InSAR techniques, difficulties come mainly from water vapor signal, orbital error and limited temporal coherence as strain accumulation around active fault occurs over a large area that include natural, and often rugged terrain. Using ERS data, and conventional InSAR technique, Wright et al (2001) were able to measure slow ground deformation of about 1 cm/year (along the radar line of sight) over 100 km across the eastern end of the North Anatolian Fault (NAF), Turkey. This measurement is consistent with GPS data and an elastic model of interseismic strain accumulation. Nonetheless, it is affected by 2-sigma error as large as 0.3 cm/year, due to the small number of interferograms available that fulfill the selection criteria for such a conventional InSAR analysis. Such an error would have been too large to detect strain around many other faults with smaller interseismic slip rate. Aiming to improve the accuracy of measurement of interseismic deformation, we test the Persistent Scatterer Interferometry (PSI) technique on the same site. Starting from 44 descending ERS SAR raw images, SLC images are focused with ROIpac software. Subsequent interferometric and PSI processing is performed using TU Delft's DORIS and DORIS-PS software. We will present comparison of the different methods at our test site and discuss the use of InSAR techniques for measuring interseismic deformation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AGUFM.G51C0839P
- Keywords:
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- 1209 Tectonic deformation (6924);
- 8194 Instruments and techniques;
- 9335 Europe