Non-linear arrival time tomography

• Main Authors: G. Nolet, C. B. Papazachos
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 1997-06-01
• Series: Annals of Geophysics
• Subjects: non-linear inversion; arrival times; graph theory; bending; 3D ray tracing
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/3937

The use of 1D or pseudo- 3D ray tracing techniques in linearized tomographic problems leads to solutions for which it is difficult to assess the true resolution and error distribution. For this reason, we employ a revised 3D bending algorithm (Moser et al., 1992) and show that it can be used efficiently for a non-linear inversion in a stepwise scheme. Initial paths are determined from graph theory in order to avoid local minima in bending. The importance of 3D ray tracing in inversion studies and the limitations of the standard 1D approach are demonstrated through synthetic examples. The speed of the ray tracing and the simple scaling scheme allow for an implementation in large-scale tomographic problems.