2009GL040434.pdf (1.2 MB)
Download file

Fundamental and higher-mode Rayleigh wave characteristics of ambient seismic noise in New Zealand

Download (1.2 MB)
journal contribution
posted on 09.02.2021, 19:12 by L Brooks, John TownendJohn Townend, P Gerstoft, S Bannister, Lionel CarterLionel Carter
In order to use ambient seismic noise for mapping Earth's structure, it is important to understand the spatiotemporal characteristics of the noise field. This study uses data collected during four austral winter months of 2002 to investigate New Zealand's ambient seismic noise field in the double-ocean-wave-frequency range (0.1-0.3 Hz). It is shown via beamforming analysis that there are two distinct dispersive waves in the data. These waves can be separated. Their estimated phase velocities (2.5-2 and 4-3 km/s in the frequency range 0.14-0.25 Hz) match well with fundamental and higher-mode Rayleigh dispersion curves. Studies of double-wave-frequency microseisms elsewhere generally show the Rayleigh noise fields to be dominated by fundamental mode waves. The reason why higher-mode signals are observed here may reflect a combination of long ocean wave periods, large waveheights, the direct deep water approach to narrow continental margins, and the proximity of the seismograph array to the source regions. Copyright 2009 by the American Geophysical Union.

History

Preferred citation

Brooks, L., Townend, J., Gerstoft, P., Bannister, S. & Carter, L. (2009). Fundamental and higher-mode Rayleigh wave characteristics of ambient seismic noise in New Zealand. Geophysical Research Letters, 36(L23303), L23303 -1-L23303 - 5. https://doi.org/10.1029/2009GL040434

Journal title

Geophysical Research Letters

Volume

36

Issue

L23303

Publication date

01/01/2009

Pagination

L23303 -1-L23303 - 5

Publisher

American Geophysical Union (AGU)

Publication status

Published

Contribution type

Article

Online publication date

02/12/2009

ISSN

0094-8276

eISSN

1944-8007

Article number

L23303

Language

en