A Surface Wave Dispersion Study of the Middle East and North Africa for Monitoring the Comprehensive Nuclear-Test-Ban Treaty

Pasyanos, Michael E.; Walter, William R.; Hazler, S. E.

doi:10.1007/978-3-0348-8264-4_7

Cited by 39 publications

(61 citation statements)

References 31 publications

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“…167, (2010) Surface Wave Tomography of the Qinghai-Tibet Plateau 1175 to measure with least possible bias the dispersion of every wave train. We obtain the Rayleigh-wave group-velocity dispersion curve by applying a narrow bandwidth Gaussian filter to the ground-motion vertical component corrected for station response over many different periods (HERRMANN, 1973;PASYANOS and WALTER, 2001). Similarly, we obtain Love dispersion measurements by applying the same filter to the data rotated and converted into transverse motion (RAYKOVA and NIKOLOVA, 2003).…”

Section: Dispersion Analysismentioning

confidence: 99%

“…Therefore, in view of the dispersive character of the elastic medium, a detailed group velocity dispersion analysis of the waves recorded from earthquakes leads to a good resolution for depth-layered properties, and may be of great interest for the determination of regional seismic velocity structure and exploration of the contrasting geology between neighbouring geological formations (CORCHETE et al, 1995;BADAL et al, 1996;BONNER and HERRIN, 1999;MARTÍNEZ et al, 2000;FREDERIKSEN et al, 2001;MISHRA et al, 2005;MITRA et al, 2006). Surface wave velocity tomography (YANOVSKAYA et al, 2000;HUANG et al, 2003;YANOVSKAYA and KOZHEVNIKOV, 2003) is a useful tool for this purpose and for monitoring nuclear explosions with discriminants (PASYANOS and WALTER, 2001).…”

Section: Introductionmentioning

confidence: 99%

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Love and Rayleigh Wave Tomography of the Qinghai-Tibet Plateau and Surrounding Areas

Chen

Badal

2009

Pure Appl. Geophys.

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Surface wave data were initially collected from events of magnitude Ms C 5.0 and shallow or moderate focal depth occurred between 1980 and 2002: 713 of them generated Rayleigh waves and 660 Love waves, which were recorded by 13 broadband digital stations in Eurasia and India. Up to 1,525 source-station Rayleigh waveforms and 1,464 Love wave trains have been processed by frequency-time analysis to obtain group velocities. After inverting the path-averaged group times by means of a damped least-squares approach, we have retrieved location-dependent group velocities on a 2°9 2°-sized grid and constructed Rayleighand Love-wave group velocity maps at periods 10.4-105.0 s. Resolution and covariance matrices and the rms group velocity misfit have been computed in order to check the quality of the results. Afterwards, depth-dependent SV-and SH-wave velocity models of the crust and upper mantle are obtained by inversion of local Rayleigh-and Love-wave group velocities using a differential damped least-squares method. The results provide: (a) Rayleighand Love-wave group velocities at various periods; (b) SV-and SH-wave differential velocity maps at different depths; (c) sharp images of the subducted lithosphere by velocity cross sections along prefixed profiles; (d) regionalized dispersion curves and velocity-depth models related to the main geological formations. The lithospheric root presents a depth that can be substantiated at *140 km (Qiangtang Block) and exceptionally at *180 km in some places (Lhasa Block), and which exhibits laterally varying fast velocity very close to that of some shields that even reaches *4.8 km/s under the northern Lhasa Block and the Qiangtang Block. Slow-velocity anomalies of 7-10% or more beneath southern Tibet and the eastern edge of the Plateau support the idea of a mechanically weak middle-to-lower crust and the existence of crustal flow in Tibet.

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Section: Dispersion Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Love and Rayleigh Wave Tomography of the Qinghai-Tibet Plateau and Surrounding Areas

Chen

Badal

2009

Pure Appl. Geophys.

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“…Next, we assign geophysical properties to each region based mainly on the literature review, augmented with ongoing studies of regional phase propagation characteristics and seismic monitoring discriminant effectiveness (e.g., RODGERS et al, 1999;MCNAMARA and WALTER, 2001;PASYANOS et al, 2001PASYANOS et al, , 2003. A major difficulty in estimating lithospheric structure in Western Eurasia and North Africa is the nearly complete lack of large-scale refraction profiles and other seismic investigations in the region, particularly in comparison to North America, Europe, and portions of Asia.…”

Section: Regionalized Crustal Model Of Western Eurasia and North Africamentioning

confidence: 99%

“…Our initial results are compared to the group velocity tomography over a broad period range (in this case 10-100 seconds); results are shown in Figure 4 between the WENA1.0 model and the surface wave tomography (PASYANOS et al, 2001). At 20 s period (Fig.…”

Section: Surface Wave Group Velocitymentioning

confidence: 99%

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Building and Testing an a priori Geophysical Model for Western Eurasia and North Africa

Pasyanos

Walter

Flanagan

et al. 2004

Pure and Applied Geophysics

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We construct and evaluate a new three-dimensional model of crust and upper mantle structure in Western Eurasia and North Africa (WENA) extending to 700 km depth and having 1°p arameterization. The model is compiled in an a priori fashion entirely from existing geophysical literature, specifically, combining two regionalized crustal models with a high-resolution global sediment model and a global upper mantle model. The resulting WENA1.0 model consists of 24 layers: water, three sediment layers, upper, middle, and lower crust, uppermost mantle, and 16 additional upper mantle layers. Each of the layers is specified by its depth, compressional and shear velocity, density, and attenuation (quality factors, Q P and Q S ). The model is tested by comparing the model predictions with geophysical observations including: crustal thickness, surface wave group and phase velocities, upper mantle P n velocities, receiver functions, P-wave travel times, waveform characteristics, regional 1-D velocities, and Bouguer gravity. We find generally good agreement between WENA1.0 model predictions and empirical observations for a wide variety of independent data sets. We believe this model is representative of our current knowledge of crust and upper mantle structure in the WENA region and can successfully be used to model the propagation characteristics of regional seismic waveform data. The WENA1.0 model will continue to evolve as new data are incorporated into future validations and any new deficiencies in the model are identified. Eventually this a priori model will serve as the initial starting model for a multiple data set tomographic inversion for structure of the Eurasian continent.

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Vertical midscale ionospheric disturbances caused by surface seismic waves based on Irkutsk chirp ionosonde data in 2011–2016

et al. 2017

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Based on the Irkutsk fast monostatic chirp ionosonde data, we made a statistical analysis of ionospheric effects for 28 earthquakes which appeared in 2011–2016 years. These effects are related with surface (Rayleigh) seismic waves far from epicenter. The analysis has shown that nine of these earthquakes were accompanied by vertical midscale ionospheric irregularities (multicusp). To estimate the ionospheric efficiency of the seismic waves, we proposed new index KW. The index estimates the maximal amplitude of the acoustic shock wave generated by given spatial distribution of seismic vibrations and related with maximal spectral power of seismic oscillations. Based on the analysis of experimental data, we have shown that earthquake‐related multicusp (5–25 s irregularities) is observed mostly at daytime [07:00–17:00] LST for KW≥4.7. The observations of acoustic waves by GPS technique in the epicenter vicinity (120–600 s irregularities) do not show such a daytime dependence. Based on 24 May 2013 Okhotsk Sea earthquake example, we demonstrated that deep‐focus earthquakes can produce strong multicusp far from the epicenter, although do not produce significant GPS ionospheric response in the epicenter vicinity.

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A Surface Wave Dispersion Study of the Middle East and North Africa for Monitoring the Comprehensive Nuclear-Test-Ban Treaty

Cited by 39 publications

References 31 publications

Love and Rayleigh Wave Tomography of the Qinghai-Tibet Plateau and Surrounding Areas

Love and Rayleigh Wave Tomography of the Qinghai-Tibet Plateau and Surrounding Areas

Building and Testing an a priori Geophysical Model for Western Eurasia and North Africa

Vertical midscale ionospheric disturbances caused by surface seismic waves based on Irkutsk chirp ionosonde data in 2011–2016

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