Kinematic inversion for the 2-D horizontal and vertical qP-wave velocities and depths to interfaces applied to the TACT seismic profile, southern Alaska

• Published in: Geophysical Journal International
• Main Authors: Boztepe, E. A., Braile, L. W.
• Format: Text
• Language: English
• Published: Oxford University Press 1994
• Subjects: Articles; Trans Alaska Crustal Transect; Alaska
• Online Access: http://gji.oxfordjournals.org/cgi/content/short/119/2/529; https://doi.org/10.1111/j.1365-246X.1994.tb00140.x

We propose a quasi-compressional wave ( q P -wave) traveltime inversion technique for determination of the 2-D horizontal and vertical q P -wave velocities and depths to interfaces from seismic reflection/refraction data sets. Synthetic test model studies demonstrate that the method is effective if ray-path coverage within the model is adequate, and indicate that horizontal q P -wave velocities and depths to interfaces are better resolved than vertical q P -wave velocities. We applied our inversion technique to the Trans-Alaska Crustal Transect (TACT) profile, southern Alaska, between SP19 and SP11. The results of the inversion suggest that the upper 5 km of the crust is anisotropic. The range of anisotropy for the derived model is between 10 and 25 per cent, consistent with the range determined in previous studies and from laboratory measurements. The cause of anisotropy is thought to be preferred mineral orientations in the foliation planes of the metasedimentary rocks. Based on the test model studies and the applications to actual seismic data sets, it is suggested that future traveltime inversion studies will require particularly high-quality data with dense ray-path coverage in which multiple sources and receivers and both reflection and refraction data are utilized.