Three-dimensional imaging of the P- and S-wave velocity structure and earthquake locations beneath Southwest Iceland

Tryggvason, Ari; Rögnvaldsson, Sigur ður Th.; Flóvenz, Ólavur G.

doi:10.1046/j.1365-246x.2002.01812.x

Cited by 185 publications

(182 citation statements)

References 64 publications

Supporting

Mentioning

164

Contrasting

Order By: Relevance

“…Joint inversion is not yet a standard tool in geophysical applications, mainly because robust and well-established petrophysical models that can be used to couple the models are usually only available for certain geophysical parameters, such as compressional and shear wave slownesses (Tryggvason et al, 2002). Furthermore, petrophysical models often apply only in restricted geological settings (e.g., Sen et al, 1981;Marion et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster Bacterial Transport Site

et al. 2008

View full text Add to dashboard Cite

Abstract:The structural approach to joint inversion, entailing common boundaries or gradients, offers a flexible way to invert diverse types of surface-based and/or crosshole geophysical data. The cross-gradients function has been introduced as a means to construct models in which spatial changes in two models are parallel or anti-parallel. Inversion methods that use such structural constraints also provide estimates of non-linear and non-unique field-scale relationships between model parameters. Here, we invert jointly crosshole radar and seismic traveltimes for structurally similar models using an iterative non-linear traveltime tomography algorithm.Application of the inversion scheme to synthetic data demonstrates that it better resolves lithological boundaries than the individual inversions. Tests of the scheme on observed radar and seismic data acquired within a shallow aquifer illustrate that the resultant models have improved correlations with flowmeter data than with models based on individual inversions.The highest correlation with the flowmeter data is obtained when the joint inversion is combined with a stochastic regularization operator, where the vertical integral scale is estimated from the flowmeter data. Point-spread functions shows that the most significant resolution improvements of the joint inversion is in the horizontal direction.2

show abstract

Section: Introductionmentioning

confidence: 99%

Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster Bacterial Transport Site

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Dissipative effects are strongly mitigated by the misfit function and are neglected too. The starting model for V p is obtained from (TTT) (Tryggvason et al, 2002), and half of V p is taken as initial for V s . We denoised the data with a band-pass filter (ranging from 10-40 Hz) applied twice, and deleted the worst traces following a mean criterion.…”

Section: D Elastic Full Waveform Inversionmentioning

confidence: 99%

3D Elastic Full Waveform Inversion - On Land Study case

Kormann¹,

Martí²,

Rodriguez³

et al. 2016

78th EAGE Conference and Exhibition 2016

View full text Add to dashboard Cite

SUMMARYFull Waveform Inversion is one of the most advanced processing methods that is recently reaching a mature state after years of solving theoretical and technical issues such as the non-uniqueness of the solution and harnessing the huge computational power required by realistic scenarios. In this work, we present the application of this method to a 3D on-land dataset acquired to characterize the shallow subsurface. The current study explores the possibility to apply elastic isotropic Full Waveform Inversion using only the vertical component of the recorded seismograms. One of the main challenges in this case study remains the costly 3D modeling that includes topography and free surface effects. Nevertheless, the resulting models provide a higher resolution of the subsurface structures than starting models, and show a good correlation with the available borehole measurements.

show abstract

“…(a) Map of the investigated area in Iceland with microseismic field data. The blue dots mark the earthquake locations projected onto the surface, the red triangles refer to locations of the recording stations named with three letters, and the black diamonds denote the computational grid points of the regional traveltime tomography done by Tryggvason et al (2002). ( To construct an image (using eq.…”

Section: Field Data Examplementioning

confidence: 99%

“…earthquakes) of moment magnitude between 0.9 and 1.2. Initial P-and S-wave speeds were taken from the model of Tryggvason et al (2002) obtained using regional-scale traveltime tomography. These velocity models are shown in Figs 12(a) and (b), along with the SICP image in Fig.…”

Section: Field Data Examplementioning

confidence: 99%

Source-independent full wavefield converted-phase elastic migration velocity analysis

Shabelansky

Malcolm

Fehler

et al. 2014

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YConverted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical seismic profile (VSP) studies. Our approach is based on the crosscorrelation between reflected or transmitted PP and CP PS (and/or SS and CP SP) waves propagated backward in time, and is formulated as an optimization problem with a differential semblance criterion objective function for the simultaneous update of both P-and S-wave velocity models. The merit of this approach is that it is fully data-driven, uses full waveform information, and requires only one elastic backward propagation to form an image rather than the two (one forward and one backward) propagations needed for standard reverse-time migration. Moreover, as the method does not require forward propagation, it does not suffer from migration operator source aliasing when a small number of shots are used. We present a derivation of the method and test it with a synthetic model and field micro-seismic data.Key words: Inverse theory; Body waves; Seismic tomography; Computational seismology; Wave propagation. I N T RO D U C T I O NIn recent years, full waveform seismic imaging and velocity analysis methods have become standard and the use of elastic waves is now drawing more attention. Converted phase (CP) waves are an integrated part of the recorded elastic seismic signal and are investigated in numerous studies in the research areas of vertical seismic profile (VSP) data (e.g. Esmersoy 1990; Stewart 1991; Xiao & Leaney 2010), surface reflection (e.g. Purnell 1992;Stewart et al. 2003;Hardage et al. 2011) and transmission seismic data (e.g. Vinnik 1977;Vinnik et al. 1983;Bostock et al. 2001;Rondenay et al. 2001;Brytic et al. 2012;Shang et al. 2012;Shabelansky et al. 2013). In particular, for example Xiao & Leaney (2010) and Shang et al. (2012) showed that the CP seismic images can be calculated using one elastic propagation without using source information (i.e. location, mechanism and time-function). Source information is generally considered mandatory in standard seismic imaging and velocity analysis. However, in * Now at: Earth Sciences Department, Memorial University of Newfound- passive monitoring source information is generally not available and in active source surveys seismic data require special treatment for frequency matching due to coupling differences between soil and vibro-seis or dynamite casing. These factors affect the accuracy of the imaging and velocity estimation and add computational and processing cost. Moreover, CP elastic seismic imaging is shown to have higher resolution in Xiao & Leaney (2010) and fewer artifacts than reflection type imaging in Shabelansky et al. (2012). In this study, we present a source-independent CP (SICP) velocity anal...

show abstract

Three-dimensional imaging of the P- and S-wave velocity structure and earthquake locations beneath Southwest Iceland

Cited by 185 publications

References 64 publications

Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster Bacterial Transport Site

Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster Bacterial Transport Site

3D Elastic Full Waveform Inversion - On Land Study case

Source-independent full wavefield converted-phase elastic migration velocity analysis

Contact Info

Product

Resources

About