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Ambient noise cross-correlation observations of fundamental and higher-mode Rayleigh wave propagation governed by basement resonance

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journal contribution
posted on 09.02.2021, 19:10 by Martha Savage, FC Lin, John Townend
Measurement of basement seismic resonance frequencies can elucidate shallow velocity structure, an important factor in earthquake hazard estimation. Ambient noise cross correlation, which is well-suited to studying shallow earth structure, is commonly used to analyze fundamental-mode Rayleigh waves and, increasingly, Love waves. Here we show via multicomponent ambient noise cross correlation that the basement resonance frequency in the Canterbury region of New Zealand can be straightforwardly determined based on the horizontal to vertical amplitude ratio (H/V ratio) of the first higher-mode Rayleigh waves. At periods of 1-3 s, the first higher-mode is evident on the radial-radial cross-correlation functions but almost absent in the vertical-vertical cross-correlation functions, implying longitudinal motion and a high H/V ratio. A one-dimensional regional velocity model incorporating a ~ 1.5 km-thick sedimentary layer fits both the observed H/V ratio and Rayleigh wave group velocity. Similar analysis may enable resonance characteristics of other sedimentary basins to be determined. © 2013. American Geophysical Union. All Rights Reserved.

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Preferred citation

Savage, M., Lin, F. C. & Townend, J. (2013). Ambient noise cross-correlation observations of fundamental and higher-mode Rayleigh wave propagation governed by basement resonance. Geophysical Research Letters, 40(14), 3556-3561. https://doi.org/10.1002/grl.50678

Journal title

Geophysical Research Letters

Volume

40

Issue

14

Publication date

01/01/2013

Pagination

3556-3561

Publisher

American Geophysical Union (AGU)

Publication status

Published

Contribution type

Article

Online publication date

19/07/2013

ISSN

0094-8276

eISSN

1944-8007

Language

en

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