Article
Geochemistry & Geophysics
Bin Liu, Zhifei Gong, Fengkai Zhang, Xinji Xu, Yang Zhao, Lei Chen
Summary: This paper proposes an improved tunnel FWI method by adopting N-order time integral wavefield and normalized integration objective function method to enhance stability and reduce dependence on the initial model. The effectiveness and reliability of the method in tunnel detection environments are verified through application to synthetic models and field data.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Dirk Philip van Herwaarden, Michael Afanasiev, Solvi Thrastarson, Andreas Fichtner
Summary: We propose a new approach to full-waveform inversion that allows for continuous assimilation of growing data volumes without the need to reinvert all data. Specifically designed for seismological applications, our method utilizes a dynamic mini-batch stochastic L-BFGS to sequentially add new data while maintaining convergence and consistency in model fit measurement.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Linan Xu, Valerie Winner, Hansruedi Maurer
Summary: Seismic FWI is computationally expensive for realistically sized 3-D problems, so compact FWI (CFWI) and gradient constrained CFWI (GC-CFWI) are introduced to reduce the number of inversion model parameters. Numerical experiments show that both CFWI and GC-CFWI have good performance in 3-D acoustic FWI problems, with GC-CFWI achieving a further reduction in model parameters. The optimal model parametrization is closely related to the experimental layout.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Zeyu Zhao, Mrinal K. Sen, Bertrand Denel, Dong Sun, Paul Williamson
Summary: A hybrid optimization framework is proposed for full waveform inversion (FWI) problems, which incorporates derivative information into the model update rule and improves the convergence speed to tackle the local minima issue of non-linear inverse problems.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Nienke Blom, Phil-Simon Hardalupas, Nicholas Rawlinson
Summary: This study investigates the impact of errors in earthquake source parameters on the tomographic inverse problem and proposes strategies to mitigate artefacts caused by these errors. The results show that errors in source location and moment tensor can lead to significant time-shifts and artefacts in the tomographic models. Mitigation strategies include removing the source region from the gradient and discarding traces with small amplitudes. Horizontal mislocation is the most problematic type of error.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Qi Hu, Dario Grana, Kristopher A. Innanen
Summary: This study proposes a full waveform inversion algorithm for predicting the spatial distribution of CO2 saturation from time-lapse seismic data. The method is tested on synthetic data and compared with conventional two-step inversion algorithms, demonstrating its robustness for reconstructing baseline and monitor models.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Yuanyuan Li, Tariq Alkhalifah, Zhendong Zhang
Summary: The method combines surface seismic and well log data by using deep neural networks to learn statistical relations, effectively improving resolution and illumination for deep-buried reservoirs.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
N. Hedjazian, Y. Capdeville, T. Bodin
Summary: Seismic imaging techniques are limited by the maximum frequency in observed waveforms, leading to a smoothed, effective version of the true medium. Homogenization theory helps compute effective properties of mediums with small-scale heterogeneities, and can be used in full waveform inversion. Two-stage multiscale methods break down the seismic imaging problem, revealing the benefits of using homogenization theory.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Donggeon Kim, Jongha Hwang, Dong-Joo Min, Ju-Won Oh, Tariq Alkhalifah
Summary: Full waveform inversion (FWI) is a highly non-linear optimization problem that aims to reconstruct high-resolution subsurface structures. In this study, a two-step strategy is proposed to separate a given model into reflectivity and background velocity models and alternately update them using diffraction-angle filtering (DAF) based scale-separation technique, which effectively controls the wavenumber components and reconstructs low-wavenumber structures from the reflected waves.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Scott D. Keating, Kristopher A. Innanen
Summary: Prior knowledge in seismic inversion can improve the accuracy of models compared to using seismic data alone. This study proposes an optimization strategy for full waveform inversion (FWI) that incorporates global regularization information and allows models to 'tunnel' between basins to honor prior information.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Xin Zhang, Angus Lomas, Muhong Zhou, York Zheng, Andrew Curtis
Summary: Seismic full-waveform inversion (FWI) provides high resolution images of the subsurface by solving a highly non-linear and non-unique inverse problem using Bayesian inference. This study applies three variational inference methods (ADVI, SVGD, and sSVGD) to a 3-D FWI problem and compares their performance. The results show that ADVI is the most computationally efficient but underestimates uncertainty, while sSVGD provides the most accurate results at intermediate computational cost.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Chao Li, Guochang Liu, Yong Deng
Summary: In this study, a novel Q-compensated nonstationary phase-corrected FWI method was proposed to improve the inversion efficiency in the case of a poor initial model. The method incorporates attenuation compensation mechanism and nonstationary phase correction method to mitigate gradient energy loss and phase mismatch. It also has the ability to mitigate cycle skipping.
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Wei Zhang, Jinghuai Gao, Zhaoqi Gao, Hongling Chen
Summary: The article presents a new approach to FWI based on adjoint-driven deep learning, using a fully convolutional network to achieve high-resolution inversion of subsurface velocity. It addresses the issues of ill-posedness, nonlinearity, and cycle-skipping that are common in traditional methods.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Geochemistry & Geophysics
Tan Qin, Thomas Bohlen, Niklas Allroggen
Summary: In this study, a frequency-dependent ground-penetrating radar (GPR) full-waveform inversion (FWI) method is developed to improve the reconstruction of dielectric permittivity and electrical conductivity models. The permittivity attenuation acts as a low-pass filter and is necessary for a robust conductivity reconstruction in a high permittivity attenuation environment.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Claudia Gras, Clara Estela Jimenez-Tejero, Valenti Sallares, Adria Melendez, Cesar R. Ranero
Summary: The study introduces a generalized workflow for retrieving high-resolution P-wave velocity models of complex Earth's subsurface structures from traditional marine near-vertical seismic reflection experiments. By combining downward continuation, travel-time tomography, and full-waveform inversion, the workflow overcomes nonlinearity issues and accurately predicts the quality of the results. Testing with challenging synthetic target models shows that the workflow is efficient in obtaining high-resolution velocity models using limited field datasets.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Li-Yu Kan, Sebastien Chevrot, Vadim Monteiller
Summary: The density and seismic velocity models in central Oregon reveal the water expelled by the dehydration of subducting slabs, which leads to the serpentinization of the mantle wedge and the formation of melt and arc magmatism. The distribution of tremors at the surface corresponds with the horizontal extent of the low-velocity layer associated with fluid-saturated oceanic crust. Quartz mineralization occurs in the crust due to the presence of silica-saturated fluids, and partial melting is observed beneath the volcanic arc at around 75 km depth.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)