Seismic Tomography
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. The use of seismic tomography to describe the upper crustal structure beneath the Chalupas Caldera, Ecuador
Abstract The Chalupas Caldera is a rhyolitic volcano located in the Eastern Cordillera to the Southeast of the Cotopaxi Volcano in the Ecuadorian Andes. It is supposedly fed by a huge magmatic chamber below the caldera. For studying the Chalupas magmatic chamber, the tomographic models obtained by a Tarantola-Valette inversion and studied previously in the e
REM, Int. Eng. J.. Publicado em: 2021-06
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2. Conjugate Gradient Method for the Solution of Inverse Problems: Application in Linear Seismic Tomography
RESUMO Consideramos o uso do método do gradientes conjugados para as equações normais na solução de problemas inversos decorrentes da tomografia sísmica. Empregamos um modelo linear de tomografia de tempos de trânsito, que é caracterizado por um sistema linear mal condicionado em que as incógnitas representam a vagarosidade em cada bloco do domínio
TEMA (São Carlos). Publicado em: 2015-12
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3. Seismic ray tomography using L1 integral norm
O alto consumo de tempo em processamento computacional é um problema que, geralmente, está associado aos métodos de tomografia sísmica. Isto ocorre porque, em cada passo do processo iterativo de inversão definido pelo método tomográfico, o problema da conexão de dois pontos, pela curva da trajetória do raio sísmico, deve ser resolvido para cada par
Revista Brasileira de Geofísica. Publicado em: 2011-06
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4. Seismic data inversion by cross-hole tomography using geometrically uniform spatial coverage
One of the inversion schemes most employed in seismic tomography processing is least squares and derived algorithms, using as input data the vector of first arrivals. A division of the whole space between sources and receivers is performed, constructing a pixel model with its elements of the same size. Spatial coverage is defined, then, as the sum of travele
Revista Brasileira de Geofísica. Publicado em: 2010-03
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5. Seismic tomography with P- and S-waves for the study of the upper mantle in Brazil / Tomografia sísmica com ondas P e S para o estudo do manto superior no Brasil
We used travel time seismic tomography to study the upper mantle beneath SE and Central Brazil. This method is based on the inversion of P- and S-wave relative travel time residuals (VanDecar, 1991) obtained from more than 80 stations in an area of 20 x 20 degrees. More than 11000 P and PKP residuals, and more than 8000 S, ScS, SKS, and SKKS residuals were o
Publicado em: 2008
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6. "Ampliação da tomografia sísmica do manto superior no sudeste e centro-oeste do Brasil com ondas P" / Extension of Upper Mantle Seismic Tomography in Southeast and Central Brazil using P-waves
Variações dos tempos de percurso de fases P e PKP foram usados para tomografia sísmica do manto superior sob o sudeste e centro-oeste do Brasil. Os principais objetivos foram: Melhorar a resolução obtida pelos estudos anteriores (VanDecar et al,. 1995; Escalante, 2002; Schimmel et al., 2003, feitos de 1992 a 2001) com a inclusão de novos dados e estaç
Publicado em: 2003
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7. Mantle dynamics and seismic tomography
Three-dimensional imaging of the Earth's interior, called seismic tomography, has achieved breakthrough advances in the last two decades, revealing fundamental geodynamical processes throughout the Earth's mantle and core. Convective circulation of the entire mantle is taking place, with subducted oceanic lithosphere sinking into the lower mantle, overc
The National Academy of Sciences.
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8. Shear waves in the diamond-anvil cell reveal pressure-induced instability in (Mg,Fe)O
The emerging picture of Earth's deep interior from seismic tomography indicates more complexity than previously thought. The presence of lateral anisotropy and heterogeneity in Earth's mantle highlights the need for fully anisotropic elasticity data from mineral physics. A breakthrough in high-frequency (gigahertz) ultrasound has resulted in transmission of
National Academy of Sciences.