Noise correlation analysis: the role of the inflection points in the formation of zero-time waves

Xia，Yingjie1,2; Feng，Xuping1,2; Chen，Xiaofei1,2

2024

10.1093/gji/ggad426

Geophysical Journal International   影响因子和分区

0956-540X

1365-246X

The cross-correlation function (CCF) of seismic noise recorded at two stations often exhibits a prominent burst of energy near zero time. However, the excitation mechanism of such unexpected signals remains unclear. In this study, we demonstrate that this phenomenon arises from constructive interference of body waves radiating from sources near the mid-vertical plane between two receivers. This interference is driven by the occurrence of an inflection point effect in the traveltime difference between waves reaching the two receivers. When noise source distribution is asymmetric, the cumulative effect of such sources results in the generation of zero-time waves. It is noteworthy that a noise source distribution that is either uniform or follows a cosφ pattern, with φ denoting the azimuth from the centre of the receiver pair, can counteract the formation of these waves. Additionally, our investigation reveals that this constructive interference does not occur in the correlation of 2-D surface waves. We used numerical simulation to support our findings. In conclusion, this study offers a theoretical explanation for the emergence of zero-time waves on the CCF and provides efficient means of investigating the extraction of inter-receiver waves with uneven noise source distribution.

Body waves Coda waves Seismic interferometry Theoretical seismology Wave propagation

SCI ; EI

英语

第一

GEOSCIENCES

2-s2.0-85177755251

Scopus

1.Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology,Southern University of Science and Technology,Shenzhen,518055,China
2.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,518055,China

Xia，Yingjie,Feng，Xuping,Chen，Xiaofei. Noise correlation analysis: the role of the inflection points in the formation of zero-time waves[J]. Geophysical Journal International,2024,236(1):174-182.

Xia，Yingjie,Feng，Xuping,&Chen，Xiaofei.(2024).Noise correlation analysis: the role of the inflection points in the formation of zero-time waves.Geophysical Journal International,236(1),174-182.

Xia，Yingjie,et al."Noise correlation analysis: the role of the inflection points in the formation of zero-time waves".Geophysical Journal International 236.1(2024):174-182.