Bayesian inference of kinematic earthquake rupture parameters through fitting of strong motion data     

D. Monelli  P. M. Mai 《Geophysical Journal International》2008,173(1):220-232

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Non-parametric seismic data recovery with curvelet frames   总被引：12，自引：0，他引：12  

Felix J. Herrmann  Gilles Hennenfent 《Geophysical Journal International》2008,173(1):233-248

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Waveform inversion in the Laplace domain   总被引：12，自引：0，他引：12  

Changsoo Shin  Young Ho Cha 《Geophysical Journal International》2008,173(3):922-931

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A non-linear geodetic data inversion using ABIC for slip distribution on a fault with an unknown dip angle   总被引：1，自引：0，他引：1  

Yukitoshi Fukahata  Tim J. Wright 《Geophysical Journal International》2008,173(2):353-364

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Finite-frequency sensitivity kernels for global seismic wave propagation based upon adjoint methods   总被引：1，自引：0，他引：1  

Qinya Liu  Jeroen Tromp † 《Geophysical Journal International》2008,174(1):265-286

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Stable inversions for complete moment tensors   总被引：5，自引：0，他引：5  

Sarah E. Minson  Douglas S. Dreger 《Geophysical Journal International》2008,174(2):585-592

The seismic moment tensors for certain types of sources, such as volcanic earthquakes and nuclear explosions are expected to contain an isotropic component. Some earlier efforts to calculate the isotropic component of these sources are flawed due to an error in the method of Jost & Herrmann. We corrected the method after Herrmann & Hutchensen and found great improvement in the recovery of non-double-couple moment tensors that include an isotropic component. Tests with synthetic data demonstrate the stability of the corrected linear inversion method, and we recalculate the moment tensor solutions reported in Dreger et al. for Long Valley caldera events and Dreger & Woods for Nevada Test Site nuclear explosions. We confirm the findings of Dreger et al. that the Long Valley volcanic sources contain large statistically significant isotropic components. The nuclear explosions have strikingly anomalous source mechanisms, which contain very large isotropic components, making it evident that these events are not tectonic in origin. This indicates that moment tensor inversions could be an important tool for nuclear monitoring.  相似文献   

Surface wave tomography for azimuthal anisotropy in a strongly reduced parameter space     

Mark P. Panning  Guust Nolet 《Geophysical Journal International》2008,174(2):629-648

Large scale seismic anisotropy in the Earth's mantle is likely dynamically supported by the mantle's deformation; therefore, tomographic imaging of 3-D anisotropic mantle seismic velocity structure is an important tool to understand the dynamics of the mantle. While many previous studies have focused on special cases of symmetry of the elastic properties, it would be desirable for evaluation of dynamic models to allow more general axis orientation. In this study, we derive 3-D finite-frequency surface wave sensitivity kernels based on the Born approximation using a general expression for a hexagonal medium with an arbitrarily oriented symmetry axis. This results in kernels for two isotropic elastic coefficients, three coefficients that define the strength of anisotropy, and two angles that define the symmetry axis. The particular parametrization is chosen to allow for a physically meaningful method for reducing the number of parameters considered in an inversion, while allowing for straightforward integration with existing approaches for modelling body wave splitting intensity measurements. Example kernels calculated with this method reveal physical interpretations of how surface waveforms are affected by 3-D velocity perturbations, while also demonstrating the non-linearity of the problem as a function of symmetry axis orientation. The expressions are numerically validated using the spectral element method. While challenges remain in determining the best inversion scheme to appropriately handle the non-linearity, the approach derived here has great promise in allowing large scale models with resolution of both the strength and orientation of anisotropy.  相似文献   

Instantaneous deformation from continuous GPS: contributions from quasi-periodic loads   总被引：3，自引：0，他引：3  

Richard A. Bennett 《Geophysical Journal International》2008,174(3):1052-1064

Continuous GPS (CGPS) coordinate time-series are known to experience repeating deformation signals with seasonal and other periods. It is unlikely that these signals represent perfect sinusoids with temporally constant amplitude. We develop an analysis method that accommodates temporal variations in the amplitudes of sinusoidal signals. We apply the method to simulated coordinate time-series to numerically explore the potential consequences of neglecting decadal variation in amplitude of annual motions on the residual-error spectra of CGPS measurements, as well as potential bias in estimates for secular site velocity. We find that secular velocity bias can be appreciable for shorter time-series, and that residual-error time-series of longer duration may contain significant power in a broad band centred on semi-annual frequency if temporal variation in the amplitude of annual motions is not accounted for in the model used to reduce the observations to residuals. It may be difficult to differentiate the bandpass filtered signature of mismodelled loading signals from power-law noise, using residual-error spectra for shorter time-series. We provide an example application to a ∼9-yr coordinate time-series for a CGPS station located in southern California at Carbon Creek Control Structure (CCCS), which is known to experience large amplitude seasonal motions associated with the Santa Ana aquifer system.  相似文献   

含泥质低孔渗各向异性黏弹性介质中的波频散和衰减研究   总被引：8，自引：5，他引：3       下载免费PDF全文

聂建新  杨顶辉  巴晶 《地球物理学报》2010,53(2):385-392

本文定义了各向异性黏弹性参数修正因子,并将其引入到黏弹性模型中以体现泥质含量对黏弹性机制的影响,同时将波传播过程中孔隙介质骨架黏弹性力学机制与两种孔隙流体流动力学机制（Biot流动和喷射流动机制）有机地统一起来处理,从而给出了描述含泥质低孔渗孔隙各向异性介质中波传播规律的黏弹性Biot/squirt (BISQ)模型.数值计算结果表明,入射波的方位角、各向异性渗透率以及泥质含量等对含流体复杂孔隙介质中波频散和衰减的影响具有显著的方位各向异性特征,在低频范围内（地震波勘探频率）黏弹性力学机制对波传播能量的衰减起主导作用.  相似文献   

Definition and interests of reciprocity and reciprocity gap principles for groundwater flow problems     

Nejla T. Hariga  Amel Ben Abda  Rachida Bouhlila  Jean-Raynald de Dreuzy 《Advances in water resources》2010

We introduce the reciprocity and reciprocity gap principles for flow problems in hydrogeology and illustrate their interest in addressing identification problems. The reciprocity principle is derived from mechanics and establishes for flow problems a relationship between different sets of forcing terms, including sources, sinks and boundary conditions, and the resulting head fields. The reciprocity gap principle compares different head fields resulting from the same forcing terms applied to different structures. We give general 2D expressions of the reciprocity and reciprocity gap principles for transient flow problems and give two examples of applications for the identification of transmissivity values and interfaces between different transmissivities. Identification capacities of the reciprocity and reciprocity gap principles yielding direct inversion methods could be used as initial guesses for more advanced inverse problem methodologies.  相似文献