eprintid: 1418973 rev_number: 24 eprint_status: archive userid: 608 dir: disk0/01/41/89/73 datestamp: 2014-02-10 19:35:10 lastmod: 2022-01-18 23:39:28 status_changed: 2014-02-10 19:35:10 type: thesis metadata_visibility: show item_issues_count: 0 creators_name: Schardong, L title: Toward a high resolution tomographic imaging of the lowermost mantle ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F57 keywords: Seismology, Tomography, Body waves, Data analysis abstract: The D" layer is one of Earth's most heterogeneous location, hosting poorly understood features, which are most likely linked to the global dynamics of the mantle. Present days tomographic approaches cannot resolve correctly this area. The resolution of images from Earth's inner structure is strongly linked to precisely localizing earthquakes, and to have a good knowlegde of the frequency content of seismic waves. This thesis aims at building a global database of seismic travel times, data used for the development of tomographic images. Our method uses a more precise determination of the depths of earthquakes, allowing an improvement in measuring travel times. To a better evaluation of the frequency content, these measurements are performed in several frequency bands. A new approach for the computation of corrections to the complexity of the crust is presented as well. Finally, a preliminary imaging is presented, at regional and global scale, under the approximation of the ray theory, before a more complete description under Born approximation. date: 2012-11-05 vfaculties: VMPS elements_source: Manually entered elements_id: 926542 language_elements: French/English lyricists_name: Schardong, Lewis lyricists_id: LSCHA35 full_text_status: none thesis_type: Doctoral citation: Schardong, L; (2012) Toward a high resolution tomographic imaging of the lowermost mantle. Doctoral thesis , UNSPECIFIED.