In the last 52 years, seismic methods have improved with the development of recording instrumentation, and even more in the last 20 years with increased computational power. This has permitted to model larger amounts of data and implementing increasingly accurate numerical models, which has in turn allowed to obtain better constrained, higher- resolution models of physical properties of the Earth’s subsurface. In particular, my PhD work focuses on the development and application of seismic tomography methods to improve seismic images and models of subduction zones and particularly the inter-plate boundary zone. It consists of two parts: the first part presents the application of joint refraction and reflection travel-time tomography (TTT) to model onshore/offshore wide- angle seismic (WAS) data recorded along a profile in the North Chilean subduction zone using the tomo2d code. This work allowed me to get knowledgeable with the subroutines of this code, an experience which was applied in the second part of my work. In this second part, I modified tomo2d to allow to jointly inverting WAS and near-vertical multichannel sesimic reflection (MCS) and I showed the outstanding improvement of the inversion results by combining both types of data into a common inversion strategy. In the field data application of the first part, I have applied TTT to WAS data recorded during the Crustal Investigations off- and on-shore Nazca/Central Andes (CINCA’95) survey along ~21°S in North Chile. Results show that there is a significant change in the overriding plate properties as well as the inter-plate boundary depth along the Chile Trench. The thickness of the plate increases northwards with the deepening of the inter- plate boundary at similar distances from the trench axis. Furthermore, there is a change in surface deformation of the overriding plate visible in the orientation of faults cutting the onshore relief. Fault orientation changes from trench-parallel in the south to trench-perpendicular in the north. The borderline between the areas of different fault orientation support that there is a change in the regional stress of the overriding plate along the North Chile convergent margin. [...]

Memoria de tesis doctoral presentada por Slaven Begovic para obtener el título de Doctor en Ciencias de la Tierra por la Universitat de Barcelona (UB), realizada bajo la dirección del Dr. César Rodríguez Ranero y del Dr. Valentí Sallarés Casas del Institut de Ciències del Mar (ICM-CSIC).-- 235 pages, figures, 1 appendix

This PhD thesis is a part of ZIP: Zooming In between Plates is A Marie Curie Initial Training Network funded from the People of the European Union’s 7th Framework Programme FP7PEOPLE2013ITN under REA grant agreement no 604713. http://www.zipitn.eu/