Deformation during the 12 November 1999 Duzce, Turkey, Earthquake, from GPS and InSAR Data

Abstract

Only 87 days after the M w 7.5, 17 August 1999 İzmit earthquake, the Düzce earthquake ruptured a ca. 40-km-long adjoining strand of the North Anatolian fault (NAF) system to the east. We used displacements of 50 Global Positioning System (GPS) sites together with interferometric synthetic aperture radar (InSAR) range-change data spanning the event to estimate the geometry and slip distribution of the coseismic rupture. Postseismic deformation transients from the Düzce earthquake and the preceding İzmit event that are included in some of the measurements are corrected for using dislocation models fit to GPS data spanning the various time periods. Nonlinear inversions for fault geometry indicate that the rupture occurred on a ca. 54Њ north-dipping oblique normal, right-lateral fault. Distributed-slip inversions indicate maximum strike slip near the center of the Düzce fault close to the earthquake hypocenter. Slip magnitude and depth of faulting decrease to the west and east of the hypocenter. Both GPS and InSAR data suggest that normal slip is restricted to the shallow portion of the rupture. The Düzce earthquake had the highest slip-to-rupture-length ratio of any historic earthquake along the NAF.

Intraplate deformation of the Indian subcontinent

“…The dislocation model includes elastic strain fields from two fault segments downdip of the locked Himalayan megathrust [Larson et al, 1999], as well as contributions from thrust shear extending northward from deep below the Ndipping Dauki fault along the southern Shillong plateau edge (Figure 3). The model geometry and slip parameters are determined using non-linear inversion routines described by Bürgmann et al [2002] following the approach described by Larson et al [1999]. Strain accumulation from deep shear below the locked portion of active faults is represented by uniform-slip dislocations [Okada, 1985].…”

Combination of Precise Leveling and InSAR Data to Constrain Source Parameters of the Mw = 6.5, 26 December 2003 Bam Earthquake

“…We use a constrained nonlinear optimization algorithm (Bu¨RGMANN et al, 2002) to estimate fault parameters (fault length along strike, down-dip width, dip, depth, strike, location of the fault, and the amount of slip) that provide the best fit to the precise leveling and InSAR data. Our inversion attempts to minimize the weighted residual sum of squares…”

“…To determine the penalty factor j, we follow the lead of previous studies (Bu¨RGMANN et al, 2002;ARNADOTTIR and SEGALL, 1994) and plot a trade-off curve to find out the relative weight between the fit to the data and the model complexity. Figure 6 shows WRSS as a function of model roughness r…”

Application of Space-borne Radar Interferometry on Crustal Deformations in Taiwan: A Perspective from the Nature of Events

“…The simulation of an unwrapped interferogram from GPS data can be applied to control possible orbit error in interferometric results (e.g., Hudnut et al 1994;Burgmann et al 2002;Delouis et al 2002;Donnellan et al 2002;Feigl et al 2002). The campaign-surveyed GPS data (data after Yu et al 2001) used in this study were collected from several campaigns mainly conducted by (1) the Central Geological Survey, Ministry of Economic Affairs, (2) the Satellite Survey Division and Land Survey Bureau, Ministry of Interior, and (3) the Institute of Earth Sciences, Academia Sinica.…”