A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise
This work assesses the feasibility of the direct use of surface-wave dispersion curves from seismic ambient noise to gain insight into the crustal structure of Bransfield Strait and detect seasonal seismic velocity changes. We cross-correlated four years of vertical component ambient noise data reco...
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ftdoajarticles:oai:doaj.org/article:46fa788602ea49b49119406c8d1a00f6 2023-05-15T13:57:15+02:00 A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise K. Muhumuza 2020-01-01T00:00:00Z https://doi.org/10.1155/2020/5269537 https://doaj.org/article/46fa788602ea49b49119406c8d1a00f6 EN eng Hindawi Limited http://dx.doi.org/10.1155/2020/5269537 https://doaj.org/toc/1687-885X https://doaj.org/toc/1687-8868 1687-885X 1687-8868 doi:10.1155/2020/5269537 https://doaj.org/article/46fa788602ea49b49119406c8d1a00f6 International Journal of Geophysics, Vol 2020 (2020) Geophysics. Cosmic physics QC801-809 article 2020 ftdoajarticles https://doi.org/10.1155/2020/5269537 2022-12-31T11:25:20Z This work assesses the feasibility of the direct use of surface-wave dispersion curves from seismic ambient noise to gain insight into the crustal structure of Bransfield Strait and detect seasonal seismic velocity changes. We cross-correlated four years of vertical component ambient noise data recorded by a seismic array in West Antarctica. To estimate fundamental mode Rayleigh wave Green’s functions, the correlations are computed in 4-hr segments, stacked over 1-year time windows and moving windows of 3 months. Rayleigh wave group dispersion curves are then measured on two spectral bands—primary (10–30 s) and secondary (5–10 s) microseisms—using frequency-time analysis. We analyze the temporal evolution of seismic velocity by comparing dispersion curves for the successive annual and 3-month correlation stacks. Our main assumption was that the Green’s functions from the cross-correlations, and thus the dispersion curves, remain invariant if the crustal structure remains unchanged. Maximum amplitudes of secondary microseisms were observed during local winter when the Southern Ocean experiences winter storms. The Rayleigh wave group velocity ranges between 2.1 and 3.7 km/s, considering our period range studied. Interannual velocity variations are not much evident. We observe a slight velocity decrease in summer and increase in winter, which could be attributed to the pressure melting of ice and an increase in ice mass, respectively. The velocity anomalies observed within the crust and upper mantle structure correlate with the major crustal and upper mantle features known from previous studies in the area. Our results demonstrate that the direct comparison of surface wave dispersion curves extracted from ambient noise might be a useful tool in monitoring crustal structure variations. Article in Journal/Newspaper Antarc* Antarctica Bransfield Strait Southern Ocean West Antarctica Directory of Open Access Journals: DOAJ Articles Bransfield Strait Southern Ocean West Antarctica International Journal of Geophysics 2020 1 11 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Geophysics. Cosmic physics QC801-809 |
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Geophysics. Cosmic physics QC801-809 K. Muhumuza A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
topic_facet |
Geophysics. Cosmic physics QC801-809 |
description |
This work assesses the feasibility of the direct use of surface-wave dispersion curves from seismic ambient noise to gain insight into the crustal structure of Bransfield Strait and detect seasonal seismic velocity changes. We cross-correlated four years of vertical component ambient noise data recorded by a seismic array in West Antarctica. To estimate fundamental mode Rayleigh wave Green’s functions, the correlations are computed in 4-hr segments, stacked over 1-year time windows and moving windows of 3 months. Rayleigh wave group dispersion curves are then measured on two spectral bands—primary (10–30 s) and secondary (5–10 s) microseisms—using frequency-time analysis. We analyze the temporal evolution of seismic velocity by comparing dispersion curves for the successive annual and 3-month correlation stacks. Our main assumption was that the Green’s functions from the cross-correlations, and thus the dispersion curves, remain invariant if the crustal structure remains unchanged. Maximum amplitudes of secondary microseisms were observed during local winter when the Southern Ocean experiences winter storms. The Rayleigh wave group velocity ranges between 2.1 and 3.7 km/s, considering our period range studied. Interannual velocity variations are not much evident. We observe a slight velocity decrease in summer and increase in winter, which could be attributed to the pressure melting of ice and an increase in ice mass, respectively. The velocity anomalies observed within the crust and upper mantle structure correlate with the major crustal and upper mantle features known from previous studies in the area. Our results demonstrate that the direct comparison of surface wave dispersion curves extracted from ambient noise might be a useful tool in monitoring crustal structure variations. |
format |
Article in Journal/Newspaper |
author |
K. Muhumuza |
author_facet |
K. Muhumuza |
author_sort |
K. Muhumuza |
title |
A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
title_short |
A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
title_full |
A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
title_fullStr |
A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
title_full_unstemmed |
A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise |
title_sort |
feasibility study on monitoring crustal structure variations by direct comparison of surface wave dispersion curves from ambient seismic noise |
publisher |
Hindawi Limited |
publishDate |
2020 |
url |
https://doi.org/10.1155/2020/5269537 https://doaj.org/article/46fa788602ea49b49119406c8d1a00f6 |
geographic |
Bransfield Strait Southern Ocean West Antarctica |
geographic_facet |
Bransfield Strait Southern Ocean West Antarctica |
genre |
Antarc* Antarctica Bransfield Strait Southern Ocean West Antarctica |
genre_facet |
Antarc* Antarctica Bransfield Strait Southern Ocean West Antarctica |
op_source |
International Journal of Geophysics, Vol 2020 (2020) |
op_relation |
http://dx.doi.org/10.1155/2020/5269537 https://doaj.org/toc/1687-885X https://doaj.org/toc/1687-8868 1687-885X 1687-8868 doi:10.1155/2020/5269537 https://doaj.org/article/46fa788602ea49b49119406c8d1a00f6 |
op_doi |
https://doi.org/10.1155/2020/5269537 |
container_title |
International Journal of Geophysics |
container_volume |
2020 |
container_start_page |
1 |
op_container_end_page |
11 |
_version_ |
1766264847799943168 |