Source-Parameter Estimation by Full Waveform Inversion in 3D Heterogeneous, Viscoelastic, Anisotropic Media

Ramos-Martinez, J.; McMechan, George A.

doi:10.1785/0120000017

Cited by 19 publications

(18 citation statements)

References 31 publications

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“…However, accounting for structural inhomogeneity takes the largest effects on retrieved source parameters. Similar observations were made by Ramos- Martínez and McMechan (2001) using a finite-difference approach.…”

Section: 2 R E S U L T S O F I N V E R S I O Nsupporting

confidence: 85%

Retrieval of source parameters of an event of the 2000 West Bohemia earthquake swarm assuming an anisotropic crust

Rössler

Pšenčı́k²,

Rümpker

2007

Stud Geophys Geod

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In the recent publication (Rössler et al., 2007) we reported on small, but significant, non-shear components for one M L 3.1 earthquake in West Bohemia on 15 October 2000, which persisted even if an anisotropic crust was considered. For data analysis we used P waves recorded at temporary and permantent stations of the WEBNET of the Institute of Geophysics AS CR and of other networks. Unfortunately, only after publication of the results, we were informed that the vertical components of three stations, LBC, STC and VAC, were distorted by clipping (J. Horálek, personal communication) and thus should not be used for source retrieval. Clipping of P-wave forms was invisible at STC and VAC and difficult to detect at LBC. It could be found from an analysis of S waves, which we, unfortunately, did not study. Neither did we know the clipping level. We have therefore repeated calculations ignoring the three clipped traces. Despite omitted traces, the newly obtained source parameters did not differ much from the previous ones (see Table 1). The main differences with results published by Rössler et al., (2007) consist in the reduction of data residual by 0.01, in a small rotation of the rupture plane, and in a small decrease of non-shear components. Nevertheless, the non-shear components remain non-negligible, indicating existence of a crack opening during rupture process. Following our previous argumentation, jackknife (see Fig. 1) and bootstrap (not Table 1. Data residual R, slip inclination δ as well as mean slip inclination δ and standard deviation σ(δ) (the latter two result from bootstrap tests), rupture plane orientation, seismic moment M T (M T = M × 10 14 Nm), and moment-tensor components retrieved by using velocity Model II. Upper line: results from Rössler et al., (2007), lower line: results with the three clipped traces omitted during inversions. Slip Inclination [°] Rupture Plane [°] Moment Tensor [%] Model R δ δ σ(δ) Strike Dip Rake M DC ISO CLVD II 0.06 86.8 86.9 1.2 166 76 −40 3.6 82.0 +4.9 +13.1 II (this paper) 0.05 88.2 88.6 1.1 169 76 −39 3.5 91.4 +5.7 +2.8

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Section: 2 R E S U L T S O F I N V E R S I O Nsupporting

confidence: 85%

Retrieval of source parameters of an event of the 2000 West Bohemia earthquake swarm assuming an anisotropic crust

Rössler

Pšenčı́k²,

Rümpker

2007

Stud Geophys Geod

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“…They found that an inaccurate velocity structure could strongly bias the inverted slip distribution even when the rupture velocity, rise time and rake angle are fixed. Ramos‐Martínez and McMechan [2001] found that the 3‐D structural model for San Fernando was significantly better for determining a point source seismic moment, rake and dip than a 1‐D model. Although the 3‐D structure will not be perfectly known, we cannot assume that a 1‐D approximation to the Earth structure is a better model.…”

Section: Discussionmentioning

confidence: 96%

“…He further added “inversion theory and source modeling have advanced to the point where the Green's functions are the weakest link in the analysis.” Using synthetics, Graves and Wald [2001] similarly showed that because a 3‐D Green's function is used the resolution is not necessarily improved. Ramos‐Martínez and McMechan [2001] inverted full waveforms for point source descriptions of Northridge aftershocks. They found that that using the 3‐D structure of Magistrale et al [1998] reduced the residuals and significantly improved the uniqueness of the source compared to a 1‐D model.…”

Section: Introductionmentioning

confidence: 99%

A new nonlinear finite fault inversion with three‐dimensional Green's functions: Application to the 1989 Loma Prieta, California, earthquake

Liu

Archuleta

2004

J. Geophys. Res.

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We present a new procedure to invert for kinematic source parameters on a finite fault. On the basis of the reciprocity relation of the Green's functions, we use a newly developed fourth‐order viscoelastic finite‐difference algorithm to calculate three‐dimensional (3‐D) Green's functions (actually the tractions) on the fault. We invert the data for the unknown source parameters at the nodes (or corners) of the subfaults. The source parameters within a subfault area are allowed to vary; this variation is calculated through bilinear interpolation of the four nodal quantities. We have developed a global nonlinear inversion algorithm that is based on simulated annealing methods to solve efficiently for the nodal parameters. We apply this method to the 1989 Loma Prieta, California, M 6.9 earthquake for both a 1‐D and 3‐D velocity structure. We show (1) the bilinear interpolation technique reduces the dependence of inversion results on the subfault size by naturally including the effects of nearby subfaults. (2) While the number of synthetic seismograms that must be computed is greatly increased by the bilinear interpolation, the structure of the inversion method minimizes the actual numbers of computations. (3) As expected, complexity in the velocity structure is mapped into the source parameters that describe the rupture process; there are significant differences between faulting models derived from 1‐D and 3‐D structural models.

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“…In earthquake seismology, FWI has already been used to solve for the event location and source mechanism since more than two decades (e.g., Y. Wu & McMechan, ; Ramos‐Martinez & McMechan, ; Sokos & Zahradnik, ). Y. Wu and McMechan () used FWI to determine the spatial coordinates and origin time associated with a synthetic double‐couple source in 2‐D scenario, assuming the velocity model and the source time function are well known.…”

Section: Methodologiesmentioning

confidence: 99%

Recent Advances and Challenges of Waveform‐Based Seismic Location Methods at Multiple Scales

Tan

Schwarz

et al. 2020

Reviews of Geophysics

129

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Source locations provide fundamental information on earthquakes and lay the foundation for seismic monitoring at all scales. Seismic source location as a classical inverse problem has experienced significant methodological progress during the past century. Unlike the conventional traveltime‐based location methods that mainly utilize kinematic information, a new category of waveform‐based methods, including partial waveform stacking, time reverse imaging, wavefront tomography, and full waveform inversion, adapted from migration or stacking techniques in exploration seismology has emerged. Waveform‐based methods have shown promising results in characterizing weak seismic events at multiple scales, especially for abundant microearthquakes induced by hydraulic fracturing in unconventional and geothermal reservoirs or foreshock and aftershock activity potentially preceding tectonic earthquakes. This review presents a comprehensive summary of the current status of waveform‐based location methods, through elaboration of the methodological principles, categorization, and connections, as well as illustration of the applications to natural and induced/triggered seismicity, ranging from laboratory acoustic emission to field hydraulic fracturing‐induced seismicity, regional tectonic, and volcanic earthquakes. Taking into account recent developments in instrumentation and the increasing availability of more powerful computational resources, we highlight recent accomplishments and prevailing challenges of different waveform‐based location methods and what they promise to offer in the near future.

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Source-Parameter Estimation by Full Waveform Inversion in 3D Heterogeneous, Viscoelastic, Anisotropic Media

Cited by 19 publications

References 31 publications

Retrieval of source parameters of an event of the 2000 West Bohemia earthquake swarm assuming an anisotropic crust

Retrieval of source parameters of an event of the 2000 West Bohemia earthquake swarm assuming an anisotropic crust

A new nonlinear finite fault inversion with three‐dimensional Green's functions: Application to the 1989 Loma Prieta, California, earthquake

Recent Advances and Challenges of Waveform‐Based Seismic Location Methods at Multiple Scales

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