%0 Journal Article %1 ryberg_etal:2005 %A Ryberg, T. %A Rümpker, G. %A Haberland, C. %A Stromeyer, D. %A Weber, M. %D 2005 %J Journal of Geophysical Research %K geophysics seismology %N B3 %P B03301+ %R 10.1029/2004JB003303 %T Simultaneous inversion of shear wave splitting observations from seismic arrays %U http://dx.doi.org/10.1029/2004JB003303 %V 110 %X Seismic waveforms recorded at high-density receiver arrays facilitate the application of new inversion techniques, which take advantage of the coherent nature of the observations. We use measurements of shear wave splitting parameters from observed SKS waveforms along a dense receiver profile and compare them with splitting parameters obtained from numerical waveform modeling through anisotropic Earth models. We use two different iterative approaches for the inversion of the observed splitting parameters (1) a local optimization technique (the downhill simplex method) and (2) a global genetic algorithm search. In our forward modeling, we calculate SKS waveforms by a finite difference (FD) method solving the anisotropic wave equation, instead of deriving individual anisotropic models for each station and combining them into one model. By the comparison of FD modeling and observations we avoid a direct interpretation of the splitting parameters in terms of medium properties. We apply these techniques to the analysis of SKS phases recorded along a 100-km profile located at the Dead Sea transform fault. The measured splitting parameters show gradual short-scale variations along the profile which depend on frequency. Lateral and vertical variations of anisotropy are accounted for by two-dimensional block structures. For the simplex method the complexity of the models (the number of anisotropic blocks) is increased gradually, whereas the number of anisotropic blocks is kept fixed for the genetic algorithm search. The anisotropic structures of the best fitting models derived from the two inversion approaches agree well. The results support earlier interpretations of the observations in terms of a narrow, approximately 20 km wide, vertical decoupling zone in the mantle that accommodates the transform motion between the African and Arabian plates.

@article{ryberg_etal:2005, abstract = {Seismic waveforms recorded at high-density receiver arrays facilitate the application of new inversion techniques, which take advantage of the coherent nature of the observations. We use measurements of shear wave splitting parameters from observed SKS waveforms along a dense receiver profile and compare them with splitting parameters obtained from numerical waveform modeling through anisotropic Earth models. We use two different iterative approaches for the inversion of the observed splitting parameters (1) a local optimization technique (the downhill simplex method) and (2) a global genetic algorithm search. In our forward modeling, we calculate SKS waveforms by a finite difference (FD) method solving the anisotropic wave equation, instead of deriving individual anisotropic models for each station and combining them into one model. By the comparison of FD modeling and observations we avoid a direct interpretation of the splitting parameters in terms of medium properties. We apply these techniques to the analysis of SKS phases recorded along a 100-km profile located at the Dead Sea transform fault. The measured splitting parameters show gradual short-scale variations along the profile which depend on frequency. Lateral and vertical variations of anisotropy are accounted for by two-dimensional block structures. For the simplex method the complexity of the models (the number of anisotropic blocks) is increased gradually, whereas the number of anisotropic blocks is kept fixed for the genetic algorithm search. The anisotropic structures of the best fitting models derived from the two inversion approaches agree well. The results support earlier interpretations of the observations in terms of a narrow, approximately 20 km wide, vertical decoupling zone in the mantle that accommodates the transform motion between the African and Arabian plates.}, added-at = {2012-09-01T13:08:21.000+0200}, author = {Ryberg, T. and R\"{u}mpker, G. and Haberland, C. and Stromeyer, D. and Weber, M.}, biburl = {https://www.bibsonomy.org/bibtex/22c37f50f136aeb3c7d3e8dd64189bbcb/nilsma}, day = 4, doi = {10.1029/2004JB003303}, interhash = {fb01724ee5c9d7118bbb068ee5d23610}, intrahash = {2c37f50f136aeb3c7d3e8dd64189bbcb}, issn = {0148-0227}, journal = {Journal of Geophysical Research}, keywords = {geophysics seismology}, month = mar, number = {B3}, pages = {B03301+}, timestamp = {2021-02-09T13:25:23.000+0100}, title = {Simultaneous inversion of shear wave splitting observations from seismic arrays}, url = {http://dx.doi.org/10.1029/2004JB003303}, volume = 110, year = 2005 }