[1]ZHAO Lingyun,PANG Weidong,WANG Weitao,et al.Analysis of Characteristics of the Ambient Noise Source Using the NCF-based Beamforming[J].Journal of Seismological Research,2025,(03):413-421.[doi:10.20015/j.cnki.ISSN1000-0666.2025.0043
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
Number of periods:
2025 03
Page number:
413-421
Column:
Public date:
2025-04-15
- Title:
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Analysis of Characteristics of the Ambient Noise Source Using the NCF-based Beamforming
- Author(s):
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ZHAO Lingyun1; PANG Weidong1; WANG Weitao2; YUAN Songyong2; WANG Fang2; LI Danning1
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(1.Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)(2.Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)
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- Keywords:
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ambient noise; noise source; NCF; beamforming
- CLC:
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P315.3
- DOI:
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10.20015/j.cnki.ISSN1000-0666.2025.0043
- Abstract:
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Seismic ambient noise tomography based on dense seismic array is currently an important method for the investigation of the crustal structure.Analyzing the changes in ambient noise source plays an important role in improving our understanding of the signal of NCF.The NCF-based slowness beamforming technique can study the composition of microseisms,azimuthal anisotropy and seasonal variation.In this study,we calculate the NCF from 2013 to 2016 using the continuous vertical records of 322 broadband seismic stations which are evenly distributed in a square in southern part of the ChinArray Phase II.Using the NCF-based slowness beamforming technique,we carry out direct slowness analysis in the 4-30 s period and obtain the beamforming output in the period bands 4-8 s,8-12 s,12-20 s and 20-30 s respectively.The result shows that the components of ambient noise sources vary in different period bands.In higher-frequency bands the body wave is observed while in lower-frequency bands the body wave is weaker and surface wave signal becomes dominant.In different period bands dominant ambient noise comes from different directions,and varies along with the season.The ambient noise coming from the northern Hemisphere features stronger in Winter,and weaker in Summer.Meanwhile,the ambient noise coming from the southern Hemisphere features weaker in Winter,and stronger in Summer.This seasonality and frequency dependence of noise sources distribution is well correlated with variations of the ocean activity.