High-Resolution 3D shallow S-Wave velocity structure of Tongzhou, subcenter of Beijing, inferred from multi-mode Rayleigh waves by beamforming seismic noise at a dense array

2021 ◽  
Author(s):  
Qin Tongwei ◽  
Laiyu Lu ◽  
Zhifeng Ding ◽  
Xuanzheng Feng ◽  
Youyuan Zhang
Keyword(s):  
High Resolution ◽  
Wave Velocity ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Velocity Structure ◽  
Dense Array ◽  
S Wave ◽  
Multi Mode

scholarly journals Crustal velocity structure of the Deccan Volcanic Province, Indian Peninsula, from observed surface wave dispersion

2014 ◽  
Vol 57 (4) ◽  
Author(s):  
Gaddale Suresh ◽  
Satbir S. Teotia ◽  
Sankar N. Bhattacharya
Keyword(s):  
Wave Velocity ◽  
Rayleigh Waves ◽  
Velocity Structure ◽  
Crustal Thickness ◽  
P Wave ◽  
Upper Crust ◽  
S Wave ◽  
Deccan Volcanic Province ◽  
Epicentral Zone ◽  
Volcanic Province

<p>Through inversion of fundamental mode group velocities of Love and Rayleigh waves, we study the crustal and subcrustal structure across the central Deccan Volcanic Province (DVP), which is one of the world’s largest terrestrial flood basalts. Our analysis is based on broadband seismograms recorded at seismological station Bhopal (BHPL) in the central India from earthquakes located near west coast of India, with an average epicentral distance about 768 km. The recording station and epicentral zone are situated respectively on the northern and southern edges of DVP with wave paths across central DVP. The period of group velocity data ranges from 5 to 60 s for Rayleigh waves and 5 to 45 s for Love waves. Using the genetic algorithm, the observed data have been inverted to obtain the crust and subcrustal velocity structure along the wavepaths. Using this procedure, a similar velocity structure was also obtained earlier for the northwestern DVP, which is in the west of the present study region. Comparison of results show that the crustal thickness decreases westward from central DVP (39.6 km) to northwestern DVP (37.8 km) along with the decrease of thickness of upper crust; while the thickness of lower crust remains nearly same. From east to west S-wave velocity in the upper crust decreases by 2 to 3 per cent, while P-wave velocity in the whole crust and subcrust decreases by 3 to 6 per cent. The P- and S-wave velocities are positively correlated with crustal thickness and negatively correlated with earth’s heat flow. It appears that the elevated crustal and subcrustal temperature in the western side is the main factor for low velocities on this side.</p>

scholarly journals Shear wave velocity structure beneath Bandung basin, West Java, Indonesia from ambient noise tomography

2019 ◽  
Author(s):  
B Pranata ◽  
T Yudistira ◽  
S Widiyantoro ◽  
B Brahmantyo ◽  
P R Cummins ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Velocity Structure ◽  
Ambient Seismic Noise ◽  
Upper Crust ◽  
West Java ◽  
Shear Wave Velocity Structure

Summary We investigated the seismic shear wave velocity structure of the upper crust beneath the Bandung area in West Java, Indonesia, using ambient seismic noise tomography. We installed 60 seismographs to record ambient seismic noise continuously in the city of Bandung and its surrounding area for 8 months. After inter-station cross-correlation of recordings of ambient seismic noise, we obtained empirical Green's functions for Rayleigh waves. Group velocity dispersion curves for Rayleigh waves between periods of 1 s and 8 s were measured on each inter-station path by applying the multiple filter analysis method with phase-matched processing. The spatial variation of group velocities shows a good correlation with the geological structure of the Bandung Basin. The Rayleigh wave dispersion maps were inverted to obtain the 1D shear wave velocity profiles beneath each station, which were interpolated to infer a pseudo-3D structure under the study region. The results show that the Bandung Basin has a thick layer of sediment. Along the northern, eastern and southern mountains surrounding the Bandung Basin there is high-velocity structure, except to the west of the Tangkuban Parahu volcano, where a massive low-velocity structure extending throughout the upper crust might indicate the presence of fluids or partial melts.

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