GFZ German research centre for geo sciences

Crustal structure model for Afro-Arabian rift system

This study which has been supported by the DESIRE project began with the digitization of 2-D and 3-D P-wave velocity models for 17 wide-angle reflection / refraction profiles in the Dead Sea Transform region. Since the completion of this part of the study, the aim has been to make a 3-D, P-wave velocity, crustal structure model for the whole of the Afro-Arabian rift system from wide-angle reflection / refraction data. Presently, 124 2-D and 3-D wide-angle reflection / refraction models have been digitized and incorporated in the data base used to make the model. Using the GMT software (Wessel & Smith 1991), preliminary contoured maps of P-wave velocity at 0, 5, 10, 15, 20, 25, 30, 35 and 40 km depth, crustal thickness, Pn and average crustal velocities and depths to the 6 km/s and 7 km/s velocity surfaces have been produced. Cross-sections through the model along the Dead Sea Transform valley, across the southern Dead Sea basin, along the Red Sea, across the northern Red Sea, across the southern Red Sea into Afar and the Ethiopian rift, along the Kenya rift, across the central Kenya rift and across the southern Kenya rift have also been produced using the GMT software. As more models are digitized, the maps will be updated. Anyone interested in obtaining the 3-D model should contact me at james.mechie(at)gfz-potsdam.de. Some of the results from this study have been published in Mechie et al. (2013), Mechie (2014) and Sippel et al. (2017).

Acknowledgments
I would like to acknowledge the aid of Marco Paschke and Michaela Merz who digitized most of the profiles used in the study. I would also like to acknowledge the help of Trond Ryberg in creating the maps with the GMT software.

References

  • Wessel, P. & Smith, W.H.F., 1991. Free software helps map and display data. EOS Trans. Am. Geophys.Union, 72: 441, 445-446.
  • Mechie, J., Ben-Avraham, Z., Weber, M.H., Götze, H.-J., Koulakov, I., Mohsen, A. & Stiller, M., 2013. The distribution of Moho depths beneath the Arabian plate and margins. Tectonophysics, http://dx.doi.org/10.1016/j.tecto.2012.11.015
  • Mechie, J., 2014, The Deep Structure of the Afro-Arabian Rift System. 74th Annual Meeting of the German Geophysical Society (DGG) Karlsruhe, 10-13.3.2014
  • Sippel, J., Meeßen, C., Cacace, M., Mechie, J., Fishwick, S., Heine, C., Scheck-Wenderoth, M. and Strecker, M. R., 2017. The Kenya rift revisited: insights into lithospheric strength through data-driven 3-D gravity and thermal modelling. Solid Earth, 8, 45-81, doi:10.5194/se-8-45-2017.
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