Acoustic surface wave velocity perturbations in LiNbO3by diffusion of metals

1975 ◽  
Vol 27 (1) ◽  
pp. 8-10 ◽  
Author(s):  
R. V. Schmidt
Keyword(s):  
Surface Wave ◽  
Wave Velocity ◽  
Acoustic Surface Wave ◽  
Surface Wave Velocity

Determination of the Slip-up Time for Slip-Form System using Surface Wave Velocity

2012 ◽  
Vol 18 (1) ◽  
pp. 2074-2081
Author(s):  
Heeseok Kim ◽  
Young Jin Kim ◽  
Won Jong Chin ◽  
Hyejin Yoon ◽  
Byung Suk Kim
Keyword(s):  
Surface Wave ◽  
Wave Velocity ◽  
Surface Wave Velocity ◽  
Form System

Temperature Dependence of the Elastic Surface Wave Velocity on LiNbO3and LiTaO3

1974 ◽  
Vol 13 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Chong Sang Kim ◽  
Kazuhiko Yamanouchi ◽  
Shinji Karasawa ◽  
Kimio Shibayama
Keyword(s):  
Surface Wave ◽  
Temperature Dependence ◽  
Wave Velocity ◽  
Elastic Surface ◽  
Surface Wave Velocity

Modified Surface Wave Velocity Measurement Technique in Concrete

2006 ◽  
Vol 321-323 ◽  
pp. 314-317 ◽  
Author(s):  
Sung Woo Shin ◽  
Chung Bang Yun ◽  
Won Joon Song ◽  
Joon Hyun Lee
Keyword(s):  
Experimental Study ◽  
Wavelet Transform ◽  
Surface Wave ◽  
Wave Velocity ◽  
Measurement Technique ◽  
Velocity Measurement ◽  
Maximum Energy ◽  
Continuous Wavelet ◽  
Surface Wave Velocity ◽  
Modified Surface

A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures.

scholarly journals Using ambient seismic noise to study temporal and spatial surface wave velocity structures and ambient noise field characteristics of central South Island, New Zealand

2021 ◽  
Author(s):  
◽  
Rachel Heckels
Keyword(s):  
New Zealand ◽  
Surface Wave ◽  
Wave Velocity ◽  
Seismic Noise ◽  
Shear Velocity ◽  
Southern Alps ◽  
Ambient Seismic Noise ◽  
Near Surface ◽  
Surface Wave Velocity ◽  
Velocity Changes

<p>Ambient seismic noise is used to examine the spatial and temporal surface wave velocity structures and ambient seismic noise fields in the vicinity of different fault zone environments. This study focuses on two distinct regions of central South Island, New Zealand. The Canterbury Plains is a sedimentary basin with many minor faults, which was considered to have low seismic hazard prior to the 2010 – 2011 Canterbury earthquake sequence. We focus on the time period immediately following the 2010 Darfield earthquake, which ruptured the previously unmapped Greendale Fault. The second region of interest is the central Southern Alps. The locked portion of the Alpine Fault currently poses one of the largest seismic hazards for New Zealand. The wealth of data from both permanent and temporary seismic deployments in these regions make them ideal areas in which to assess the effectiveness of ambient noise for velocity modelling in regions surrounding faults at different stages of their seismic cycles.  Temporal velocity changes are measured following the Mw 7.1 Darfield earthquake of 4 September 2010 in the Canterbury Plains. Nine-component cross-correlations are computed from temporary and permanent seismic stations lying on and surrounding the Greendale Fault. Using the Moving-Window Cross-Spectral method, surface wave velocity changes are calculated for the four months immediately following the earthquake until 10 January 2011, for 0.1 — 1.0 Hz. An average increase in seismic velocity of 0.14 ± 0.04 % is determined throughout the region, providing the first such estimate of postseismic relaxation rates in Canterbury. Depth analyses further showed that velocity changes are confined to the uppermost 5 km of the subsurface and we attribute this to postseismic relaxation via crack-healing of the Greendale Fault and throughout the surrounding region.  Rayleigh and Love wave dispersion is examined throughout the Canterbury region. Multi-component cross-correlation functions are analysed for group and phase dispersion curves. These are inverted using frequency-time analysis for 2-D phase and group velocity maps of Rayleigh and Love waves. A high-velocity zone to the southeast of the region coincides with volcanic rocks of Banks Peninsula. Dispersion curves generated from the surface wave tomography are further inverted for one-dimensional shear velocity profiles. These models show a thin, low-velocity near surface layer consistent with the basin sediments, which thins towards the foothills of the Southern Alps. A near-surface damage zone is identified along the length of the Greendale Fault, with consistent reduced Vs velocities to depth of up to 5 km.  Surface and shear wave velocity maps are computed for the central Southern Alps to image the seismic structure of the region. Tomographic surface maps at periods of 5 – 12 s are produced from dispersion measurements of three-component cross-correlation functions. At periods of 5 – 8 s a strong NE-SW trending velocity contrast highlights the Alpine Fault. One-dimensional shear velocity models, computed from the surface wave maps, are in agreement with previous models produced by other conventional methods. An analysis of surface wave amplitudes through signal-to-noise ratios of cross-correlations reveals strong directional effects. Calculated signal-to-noise ratios are up to eight times higher for surface waves travelling north-west than for waves travelling to the south or east. We attribute this to a combination of more energetic ocean wave signals from the Southern Ocean compared to the Tasman Sea.</p>

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