scholarly journals Estimation of S-Wave Velocity Structure Model by Joint Inversion of Site Amplification, Receiver Function and Phase Velocity of Rayleigh Wave

2017 ◽  
Vol 17 (5) ◽  
pp. 5_78-5_95
Author(s):  
Hiroyuki MIURA ◽  
Atsuko MATSUO ◽  
Tatsuo KANNO ◽  
Michiko SHIGEFUJI ◽  
Tetsuo ABIRU
Keyword(s):  
Phase Velocity ◽  
Rayleigh Wave ◽  
Wave Velocity ◽  
Velocity Structure ◽  
Receiver Function ◽  
Joint Inversion ◽  
Site Amplification ◽  
Structure Model ◽  
S Wave

S-wave velocity structure of the North China from inversion of Rayleigh wave phase velocity

2014 ◽  
Vol 88 ◽  
pp. 178-191 ◽  
Author(s):  
Hao-peng Chen ◽  
Liang-bao Zhu ◽  
Qing-dong Wang ◽  
Pan Zhang ◽  
Ying-hang Yang
Keyword(s):  
Phase Velocity ◽  
Rayleigh Wave ◽  
Wave Velocity ◽  
North China ◽  
Velocity Structure ◽  
S Wave ◽  
Wave Phase ◽  
The North ◽  
Wave Phase Velocity ◽  
Rayleigh Wave Phase Velocity

scholarly journals Joint Body‐ and Surface‐Wave Tomography of Yucca Flat, Nevada, Using a Novel Seismic Source

2019 ◽  
Vol 109 (5) ◽  
pp. 1922-1934 ◽  
Author(s):  
Liam D. Toney ◽  
Robert E. Abbott ◽  
Leiph A. Preston ◽  
David G. Tang ◽  
Tori Finlay ◽  
...  
Keyword(s):  
Surface Wave ◽  
Phase Velocity ◽  
Wave Velocity ◽  
Velocity Structure ◽  
Joint Inversion ◽  
P Wave ◽  
S Wave ◽  
Surface Wave Dispersion ◽  
Velocity Models ◽  
Phase Velocity Dispersion

Abstract In preparation for the next phase of the Source Physics Experiments, we acquired an active‐source seismic dataset along two transects totaling more than 30 km in length at Yucca Flat, Nevada, on the Nevada National Security Site. Yucca Flat is a sedimentary basin which has hosted more than 650 underground nuclear tests (UGTs). The survey source was a novel 13,000 kg modified industrial pile driver. This weight drop source proved to be broadband and repeatable, richer in low frequencies (1–3 Hz) than traditional vibrator sources and capable of producing peak particle velocities similar to those produced by a 50 kg explosive charge. In this study, we performed a joint inversion of P‐wave refraction travel times and Rayleigh‐wave phase‐velocity dispersion curves for the P‐ and S‐wave velocity structure of Yucca Flat. Phase‐velocity surface‐wave dispersion measurements were obtained via the refraction microtremor method on 1 km arrays, with 80% overlap. Our P‐wave velocity models verify and expand the current understanding of Yucca Flat’s subsurface geometry and bulk properties such as depth to Paleozoic basement and shallow alluvium velocity. Areas of disagreement between this study and the current geologic model of Yucca Flat (derived from borehole studies) generally correlate with areas of widely spaced borehole control points. This provides an opportunity to update the existing model, which is used for modeling groundwater flow and radionuclide transport. Scattering caused by UGT‐related high‐contrast velocity anomalies substantially reduced the number and frequency bandwidth of usable dispersion picks. The S‐wave velocity models presented in this study agree with existing basin‐wide studies of Yucca Flat, but are compromised by diminished surface‐wave coherence as a product of this scattering. As nuclear nonproliferation monitoring moves from teleseismic to regional or even local distances, such high‐frequency (>5  Hz) scattering could prove challenging when attempting to discriminate events in areas of previous testing.

scholarly journals Assessing uncertainties in high-resolution, multifrequency receiver-function inversion: A comparison with borehole data

Geophysics ◽  
2018 ◽  
Vol 83 (3) ◽  
pp. KS11-KS22 ◽  
Author(s):  
Nicola Piana Agostinetti ◽  
Alberto Malinverno
Keyword(s):  
Wave Velocity ◽  
Receiver Function ◽  
Joint Inversion ◽  
Seismic Station ◽  
Velocity Ratio ◽  
Earth Model ◽  
Elastic Model ◽  
S Wave ◽  
Borehole Data ◽  
Sonic Log

We use teleseismic P-to-S converted waves from a permanent station to estimate the uncertainties in a 1D elastic model of the shallow crust (0–7 km depth) obtained from the inversion of receiver function (RF) data. Our earth model consists of layers with a constant S-wave velocity [Formula: see text] and P- to S-wave velocity ratio ([Formula: see text]). We apply a Bayesian formulation and transdimensional Monte Carlo sampling to compute the posterior uncertainties of the earth model. The model uncertainties rely on a realistic representation of the data uncertainties, and we estimate directly from the stacking of the teleseismic data, a full-error covariance matrix. To explore the effect of the number of teleseismic events and the RF frequency content, we compare the results of inverting a single RF computed for a cut-off filter frequency of 4 Hz with the joint inversion of four RFs computed from independent ensembles in a larger pool of events for cut-off frequencies of 0.5, 1, 2, and 4 Hz. The inversion results are compared with the lithostratigraphy and sonic-log measurements from a 7 km deep borehole drilled near the seismic station. The inversion of a single RF results in larger uncertainties in the recovered [Formula: see text] profile and in the depth to seismic discontinuities compared with the multifrequency inversion. Moreover, the multifrequency inversion predicts more accurately the depth to a velocity inversion at approximately 6 km below the surface and matches more closely the borehole sonic-log data. Our results indicate that RF data can be used to map shallow (3–5 km depth) crustal interfaces with uncertainties in the order of 300–500 m, whereas uncertainties are consistently smaller (<300 m) for interfaces in the top kilometer.

Sign in / Sign up

Export Citation Format

Share Document