Seismic imaging of deep crustal structures via reverse time migration using local earthquakes

2021 ◽  
Author(s):  
Kazuya Shiraishi ◽  
Toshiki Watanabe
Keyword(s):  
Seismic Imaging ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Local Earthquakes ◽  
Time Migration ◽  
Crustal Structures

Least-squares reverse time migration in TTI media using a pure qP-wave equation

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. S199-S216
Author(s):  
Xinru Mu ◽  
Jianping Huang ◽  
Jidong Yang ◽  
Xu Guo ◽  
Yundong Guo
Keyword(s):  
Wave Equation ◽  
Least Squares ◽  
Seismic Imaging ◽  
Synthetic Data ◽  
Transversely Isotropic ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
The Matrix ◽  
The Stability

Anisotropy is a common phenomenon in subsurface strata and should be considered in seismic imaging and inversion. Seismic imaging in a vertical transversely isotropic (VTI) medium does not take into account the effects of the tilt angles, which can lead to degraded migrated images in areas with strong anisotropy. To correct such waveform distortion, reduce related image artifacts, and improve migration resolution, a tilted transversely isotropic (TTI) least-squares reverse time migration (LSRTM) method is presented. In the LSRTM, a pure qP-wave equation is used and solved with the finite-difference method. We have analyzed the stability condition for the pure qP-wave equation using the matrix method, which is used to ensure the stability of wave propagation in the TTI medium. Based on this wave equation, we derive a corresponding demigration (Born modeling) and adjoint migration operators to implement TTI LSRTM. Numerical tests on the synthetic data show the advantages of TTI LSRTM over VTI RTM and VTI LSRTM when the recorded data contain strong effects caused by large tilt angles. Our numerical experiments illustrate that the sensitivity of the adopted TTI LSRTM to the migration velocity errors is much higher than that to the anisotropic parameters (including epsilon, delta, and tilted angle parameters), and its sensitivity to the epsilon model and tilt angle is higher than that to the delta model.

scholarly journals LEAST-SQUARE REVERSE TIME MIGRATION (LSRTM) IN THE SHOT DOMAIN

2016 ◽  
Vol 34 (3) ◽  
Author(s):  
Antonio Edson Lima de Oliveira ◽  
Reynam Da Cruz Pestana ◽  
Adriano Wagner Gomes dos Santos
Keyword(s):  
Iterative Method ◽  
Seismic Data ◽  
Seismic Imaging ◽  
Imaging Techniques ◽  
Least Square ◽  
Subsurface Imaging ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Imaging Methods ◽  
Time Migration

ABSTRACT. One of the major limitations of imaging methods is, usually, the incomplete recorded seismic data that cause difficulties for the subsurface imaging techniques...Keywords: seismic imaging, resolution, modeling, iterative method, computational coast. RESUMO. Uma das limitações das técnicas de imageamento é que, via de regra, os dados sísmicos registrados são incompletos. Isso impossibilita uma correta reconstituição dos refletores em subsuperfície...Palavras-chave: imageamento sísmico, resolução, modelagem, método iterativo, custo computacional.

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