Seismic tomographic full-waveform inversion for the Vrancea sinking lithosphere structure using the adjoint method.


Autoria(s): Baron, Julie
Contribuinte(s)

Morelli, Andrea

Data(s)

07/05/2014

Resumo

The Vrancea region, at the south-eastern bend of the Carpathian Mountains in Romania, represents one of the most puzzling seismically active zones of Europe. Beside some shallow seismicity spread across the whole Romanian territory, Vrancea is the place of an intense seismicity with the presence of a cluster of intermediate-depth foci placed in a narrow nearly vertical volume. Although large-scale mantle seismic tomographic studies have revealed the presence of a narrow, almost vertical, high-velocity body in the upper mantle, the nature and the geodynamic of this deep intra-continental seismicity is still questioned. High-resolution seismic tomography could help to reveal more details in the subcrustal structure of Vrancea. Recent developments in computational seismology as well as the availability of parallel computing now allow to potentially retrieve more information out of seismic waveforms and to reach such high-resolution models. This study was aimed to evaluate the application of a full waveform inversion tomography at regional scale for the Vrancea lithosphere using data from the 1999 six months temporary local network CALIXTO. Starting from a detailed 3D Vp, Vs and density model, built on classical travel-time tomography together with gravity data, I evaluated the improvements obtained with the full waveform inversion approach. The latter proved to be highly problem dependent and highly computational expensive. The model retrieved after the first two iterations does not show large variations with respect to the initial model but remains in agreement with previous tomographic models. It presents a well-defined downgoing slab shape high velocity anomaly, composed of a N-S horizontal anomaly in the depths between 40 and 70km linked to a nearly vertical NE-SW anomaly from 70 to 180km.

Formato

application/pdf

Identificador

http://amsdottorato.unibo.it/6540/1/Baron_Julie_tesi.pdf

urn:nbn:it:unibo-12624

Baron, Julie (2014) Seismic tomographic full-waveform inversion for the Vrancea sinking lithosphere structure using the adjoint method. , [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Geofisica <http://amsdottorato.unibo.it/view/dottorati/DOT250/>, 26 Ciclo. DOI 10.6092/unibo/amsdottorato/6540.

Idioma(s)

en

Publicador

Alma Mater Studiorum - Università di Bologna

Relação

http://amsdottorato.unibo.it/6540/

Direitos

info:eu-repo/semantics/openAccess

Palavras-Chave #GEO/10 Geofisica della terra solida
Tipo

Tesi di dottorato

NonPeerReviewed