气候变化领域集成服务门户(CCPortal): Limits and Benefits of the Spatial Autocorrelation Microtremor Array Method Due to the Incoherent Noise, With Special Reference to the Analysis of Long Wavelength Ranges

CCPortal

DOI	10.1029/2020JB019850
	Limits and Benefits of the Spatial Autocorrelation Microtremor Array Method Due to the Incoherent Noise, With Special Reference to the Analysis of Long Wavelength Ranges
	Cho I.; Iwata T.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	To examine the upper limit of the analyzable wavelength ranges (upper limit wavelength, ULW) of the spatial autocorrelation (SPAC) method in microtremor surveys, we have derived a formula evaluating stochastic errors of a phase velocity estimate obtained by the SPAC method. We then followed our previous paper to evaluate biases generated in a phase velocity estimate that come from the presence of the incoherent noise so that we could discuss which is the crucial factor determining the ULW. As a result, the incoherent noise is considered as the crucial factor. In the consequence, we proposed a formula to evaluate signal-to-noise ratio (SNR) and to determine phase velocity with the effects of the incoherent noise compensated. We used observed data to validate the above theory. Through the validation procedure, we obtained an approximation equation (Formula presented.), where NULW means ULW normalized by array radius and A is a constant. The parameter A took a value from about 1/2 to 2 in the cases of this study. Finally, an additional and simple analysis was executed, which indicates that the incoherent noise not only limits the SPAC analysis but also can provide benefits: they are possibly used for evaluating the attenuation of soils. A microtremor array survey with the traditional SPAC method of Okada (2003, https://doi.org/10.1190/1.9781560801740) can be a mobile tool for evaluating the very local attenuation at a site of interest (i.e., gaining a high spatial resolution), in frequency ranges suited for earthquake engineering and by using simple seismic arrays with short time observations. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	anelasticity; array; microtremor; Rayleigh wave; seismic interferometry; SPAC method
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187390
作者单位	Geological Survey of Japan, AIST, Tsukuba, Japan; Prefectural University of Hiroshima, Hiroshima, Japan; The Institute of Statistical Mathematics, Tokyo, Japan
推荐引用方式 GB/T 7714	Cho I.,Iwata T.. Limits and Benefits of the Spatial Autocorrelation Microtremor Array Method Due to the Incoherent Noise, With Special Reference to the Analysis of Long Wavelength Ranges[J],2021,126(2).
APA	Cho I.,&Iwata T..(2021).Limits and Benefits of the Spatial Autocorrelation Microtremor Array Method Due to the Incoherent Noise, With Special Reference to the Analysis of Long Wavelength Ranges.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Cho I.,et al."Limits and Benefits of the Spatial Autocorrelation Microtremor Array Method Due to the Incoherent Noise, With Special Reference to the Analysis of Long Wavelength Ranges".Journal of Geophysical Research: Solid Earth 126.2(2021).