Joint Inversion of Teleseismic Delay Times and Geoid Anomaly Data: New models for the Lower Crust and Upper Mantle of the Paraná Basin.

• Grant number: 09/18511-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2010
• End date: October 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Naomi Ussami
• Grantee: Carlos Alberto Moreno Chaves
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 09/50493-8 - Crustal and lithospheric mantle models under the Paraná and Chaco-Paraná basins by merging satellite gravity gradiometry, terrestrial gravimetry and geomagnetic and electromagnetic soundings, AP.TEM
• Associated scholarship(s): 13/11908-3 - Joint inversion of teleseismic delay times and geoid anomaly data: implementation of a computational algorithm to map density variations within the mantle, BE.EP.DR

Abstract

Teleseismic delay times and geoid anomalies data will be integrated and new models for the lower crust and upper mantle of the Paraná Basin will be proposed. The aim of this doctorate project is to provide additional geophysical constraints to understand the Paraná Basin evolution. Initially, geoid anomalies caused by topographical masses and due the variations of the crust, sediments and basalts thicknesses are going to be estimated. These effects will be removed from the observed geoid anomalies in order to isolate the lower crust and mantle components. Next, the teleseismic delay times will be processed to calculate the residual times which are the difference between the arrival times and the times calculated from a global reference model. The relative travel time residuals will be calculated to eliminate the errors from the processing. A joint inversion technique will be proposed in order to obtain density and seismic wave velocity models for the lower crust and upper mantle of the Paraná Basin. From these models, the thermal state of the lithosphere and inferences about the composition of the mantle beneath the Paraná Basin will be obtained. Paraná Basin volcanism may have resulted from deep geodynamic processes to be tested, some of them are: mantle plume, long-lived thermal anomaly within the mantle lithosphere, edge-driven convection at cratonic lithosphere borders or delamination of thickened lithosphere. This doctoral project is part of the FAPESP Thematic Project Process 09/50493-8 entitled "Crustal and lithospheric mantle models under the Paraná and Chaco-Paraná basins by merging satellite gravity gradiometry, terrestrial gravity and geomagnetic and electromagnetic soundings." coordinated by Professor Icaro Vitorello (INPE-MCT) and participation of IAG-USP (Naomi Ussami) and the Department of Earth Sciences of the University of Trieste (Carla Braitenberg).

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CHAVES, CARLOS; USSAMI, NAOMI; RITSEMA, JEROEN. Density and P-wave velocity structure beneath the Parana Magmatic Province: Refertilization of an ancient lithospheric mantle. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, v. 17, n. 8, p. 3054-3074, AUG 2016. (09/50493-8, 09/18511-6, 13/11908-3)

DRAGONE, GABRIEL NEGRUCCI; USSAMI, NAOMI; GIMENEZ, MARIO ERNESTO; LINCE KLINGER, FEDERICO GUSTAVO; MORENO CHAVES, CARLOS ALBERTO. Western Parana suture/shear zone and the limits of Rio Apa, Rio Tebicuary and Rio de la Plata cratons from gravity data. Precambrian Research, v. 291, p. 162-177, APR 2017. (09/18511-6, 09/50493-8, 12/06082-6)

MORENO CHAVES, CARLOS ALBERTO; USSAMI, NAOMI. Modeling 3-D density distribution in the mantle from inversion of geoid anomalies: Application to the Yellowstone Province. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, v. 118, n. 12, p. 6328-6351, DEC 2013. (09/50493-8, 09/18511-6, 08/02411-0)