Seismic studies in central and eastern Tennessee

1978 ◽  
Vol 68 (4) ◽  
pp. 1081-1094
Author(s):  
E. S. Sodbinow ◽  
G. A. Bollinger
Keyword(s):  
Surface Wave ◽  
Theoretical Models ◽  
Wave Dispersion ◽  
Time Frame ◽  
Low Noise ◽  
Cumberland Plateau ◽  
Surface Wave Dispersion ◽  
Mode Dispersion ◽  
Short Period ◽  
Wave Trains

abstract Some of the seismic characteristics of Tennessee were investigated by means of a short-period surface-wave dispersion study in central Tennessee and a microearthquake survey of the eastern portion of the state. The tripartite method of phase velocity determination was applied to data from a 4-element SPZ array at the Cumberland Plateau Observatory (CPO). Seven short-period (0.5 to 1.4 sec.) surface-wave trains were analyzed. These wave trains exhibited both fundamental and first higher mode dispersion. Theoretical models, consisting of 2 or 3 layers over a half-space were developed that explain the observed dispersion. The layers, which model the surficial sediments of the region, range in total thickness from 1.6 to 2.1 km and have shear velocities from 1.70 to 3.10 km/sec. A 5-station array of portable seismographs was deployed in eastern Tennessee and 2 months of operation yielded 3000 low-noise hours of data. Eleven microearthquakes −1.3 ≦ M ≦ 1.1 were recorded during that time frame indicating that, at least for periods of several weeks, the microseismicity of eastern Tennessee can be very low.

Short-period surface-wave dispersion and shallow crustal structure of central and eastern Tennessee

1992 ◽  
Vol 82 (2) ◽  
pp. 962-979
Author(s):  
Paul C. Yao ◽  
James Dorman
Keyword(s):  
Surface Wave ◽  
Half Space ◽  
Crustal Structure ◽  
Group Velocity Dispersion ◽  
Wave Dispersion ◽  
Surface Wave Dispersion ◽  
Zero Crossing ◽  
Clastic Rocks ◽  
Dispersion Data ◽  
Short Period

Abstract Group velocity dispersion of explosion-generated seismic surface waves with periods ranging from 0.2 to 1.5 sec is used to investigate shallow crustal structure of eastern and central Tennessee. Several modes of both Rayleigh and Love waves can be identified and separated on the seismograms of seven SARSN regional network stations by zero-phase digital filtering. Dispersion data for sinusoidal wave motion were based on digitized zero-crossing times. By forward modeling, we find that a wave guide of at least two layers over a half-space can adequately represent our particular multi-mode, narrow-band observations. In a layered section about 3 km thick, lower velocities characterize outcropping clastic rocks of the Cumberland plateau, and higher velocities correspond to shallow carbonate rocks of the Nashville Dome. Half-space shear velocities of about 3.9 km/sec appear to represent lower Paleozoic carbonate lithology deeper than 2 to 4 km on most of the observed paths. Our best data, interpreted jointly with earlier data of Oliver and Ewing (1958) and of Chen et al. (1989), have a composite period range of 0.2 to 40 sec, but they represent different Appalachian paths. Group velocities over this broad spectrum are satisfied by a complex model with two low-velocity layers. The uniqueness of this model cannot be demonstrated, but it represents important hypotheses concerning regional geologic features that can be tested more rigorously by improved surface-wave dispersion data.

An error analysis of frequency-time analysis

1983 ◽  
Vol 73 (1) ◽  
pp. 143-155
Author(s):  
Chi-Chin Feng ◽  
Ta-liang Teng
Keyword(s):  
Surface Wave ◽  
Matched Filter ◽  
Data Extraction ◽  
Wave Dispersion ◽  
Dispersion Analysis ◽  
Time Analysis ◽  
Surface Wave Dispersion ◽  
Period Range ◽  
Dispersion Measurement ◽  
Short Period

abstract The temporal resolution and accuracy of frequency-time analysis (FTAN) as applied to surface-wave dispersion analysis are examined for a period range from 10 to 200 sec. The constant relative bandwidth filter (Dziewonski et al., 1969), optimum bandwidth filter (Inston et al., 1971), and display-equalized filter (Nyman and Landisman, 1977) are carefully examined with respect to their adequacy of application over a broad period range. Among these Gaussian filters, the optimum bandwidth filter gives a better performance for relatively short-period (less than 50 sec) dispersion measurement. To measure surface-wave dispersion for a broad period range, a “matched-filter FTAN” technique is introduced by modifying the “residual dispersion measurement” technique (Dziewonski et al., 1972). A detailed numerical analysis is made on this new technique; the result demonstrates a significant improvement on both the resolution and the accuracy of surface-wave dispersion data extraction over a broad period range up to at least 200 sec.

Improved Surface Wave Dispersion Models, Amplitude Measurements and Azimuth Estimates

2005 ◽  
Author(s):  
Jeffry L. Stevens ◽  
David A. Adams ◽  
G. E. Baker ◽  
Mariana G. Eneva ◽  
Heming Xu
Keyword(s):  
Surface Wave ◽  
Wave Dispersion ◽  
Dispersion Models ◽  
Surface Wave Dispersion

scholarly journals Imaging the subsurface using induced seismicity and ambient noise: 3-D tomographic Monte Carlo joint inversion of earthquake body wave traveltimes and surface wave dispersion

2020 ◽  
Vol 222 (3) ◽  
pp. 1639-1655
Author(s):  
Xin Zhang ◽  
Corinna Roy ◽  
Andrew Curtis ◽  
Andy Nowacki ◽  
Brian Baptie
Keyword(s):  
Surface Wave ◽  
Ambient Noise ◽  
Velocity Structure ◽  
Joint Inversion ◽  
Body Wave ◽  
Source Parameters ◽  
Wave Dispersion ◽  
Inversion Method ◽  
Surface Wave Dispersion ◽  
Wave Data

SUMMARY Seismic body wave traveltime tomography and surface wave dispersion tomography have been used widely to characterize earthquakes and to study the subsurface structure of the Earth. Since these types of problem are often significantly non-linear and have non-unique solutions, Markov chain Monte Carlo methods have been used to find probabilistic solutions. Body and surface wave data are usually inverted separately to produce independent velocity models. However, body wave tomography is generally sensitive to structure around the subvolume in which earthquakes occur and produces limited resolution in the shallower Earth, whereas surface wave tomography is often sensitive to shallower structure. To better estimate subsurface properties, we therefore jointly invert for the seismic velocity structure and earthquake locations using body and surface wave data simultaneously. We apply the new joint inversion method to a mining site in the United Kingdom at which induced seismicity occurred and was recorded on a small local network of stations, and where ambient noise recordings are available from the same stations. The ambient noise is processed to obtain inter-receiver surface wave dispersion measurements which are inverted jointly with body wave arrival times from local earthquakes. The results show that by using both types of data, the earthquake source parameters and the velocity structure can be better constrained than in independent inversions. To further understand and interpret the results, we conduct synthetic tests to compare the results from body wave inversion and joint inversion. The results show that trade-offs between source parameters and velocities appear to bias results if only body wave data are used, but this issue is largely resolved by using the joint inversion method. Thus the use of ambient seismic noise and our fully non-linear inversion provides a valuable, improved method to image the subsurface velocity and seismicity.

scholarly journals Reliable workflow for inversion of seismic receiver function and surface wave dispersion data: a “13 BB Star” case study

2019 ◽  
Vol 24 (1) ◽  
pp. 101-120
Author(s):  
Kajetan Chrapkiewicz ◽  
Monika Wilde-Piórko ◽  
Marcin Polkowski ◽  
Marek Grad
Keyword(s):  
Surface Wave ◽  
Inverse Problems ◽  
Receiver Function ◽  
Joint Inversion ◽  
Wave Dispersion ◽  
Receiver Functions ◽  
P Wave ◽  
Surface Wave Dispersion ◽  
Phase Velocity Dispersion ◽  
Wide Range

AbstractNon-linear inverse problems arising in seismology are usually addressed either by linearization or by Monte Carlo methods. Neither approach is flawless. The former needs an accurate starting model; the latter is computationally intensive. Both require careful tuning of inversion parameters. An additional challenge is posed by joint inversion of data of different sensitivities and noise levels such as receiver functions and surface wave dispersion curves. We propose a generic workflow that combines advantages of both methods by endowing the linearized approach with an ensemble of homogeneous starting models. It successfully addresses several fundamental issues inherent in a wide range of inverse problems, such as trapping by local minima, exploitation of a priori knowledge, choice of a model depth, proper weighting of data sets characterized by different uncertainties, and credibility of final models. Some of them are tackled with the aid of novel 1D checkerboard tests—an intuitive and feasible addition to the resolution matrix. We applied our workflow to study the south-western margin of the East European Craton. Rayleigh wave phase velocity dispersion and P-wave receiver function data were gathered in the passive seismic experiment “13 BB Star” (2013–2016) in the area of the crust recognized by previous borehole and refraction surveys. Final models of S-wave velocity down to 300 km depth beneath the array are characterized by proximity in the parameter space and very good data fit. The maximum value in the mantle is higher by 0.1–0.2 km/s than reported for other cratons.

Surface Wave Dispersion Imaging Using Improved τ-p Transform Approach

2013 ◽  
Vol 353-356 ◽  
pp. 1196-1202 ◽  
Author(s):  
Jian Qi Lu ◽  
Shan You Li ◽  
Wei Li
Keyword(s):  
Surface Wave ◽  
Phase Shift ◽  
Dispersion Curve ◽  
Wave Dispersion ◽  
S Wave ◽  
Surface Wave Dispersion ◽  
Narrow Frequency Range ◽  
Channel Analysis ◽  
Rayleigh Wave Dispersion

Surface wave dispersion imaging approach is crucial for multi-channel analysis of surface wave (MASW). Because the resolution of inversed S-wave velocity and thickness of a layer are directly subjected to the resolution of imaged dispersion curve. The τ-p transform approach is an efficient and commonly used approach for Rayleigh wave dispersion curve imaging. However, the conventional τ-p transform approach was severely affected by waves amplitude. So, the energy peaks of f-v spectrum were mainly gathered in a narrow frequency range. In order to remedy this shortage, an improved τ-p transform approach was proposed by this paper. Comparison has been made between phase shift and improved τ-p transform approaches using both synthetic and in situ tested data. Result shows that the dispersion image transformed from proposed approach is superior to that either from conventionally τ-p transform or from phase shift approaches.

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