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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Online Access: | https://dx.doi.org/10.48550/arxiv.1910.10767 https://arxiv.org/abs/1910.10767 |
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ftdatacite:10.48550/arxiv.1910.10767 2023-05-15T13:41:07+02:00 A feasibility study on monitoring crustal structure variations by direct comparison of surface wave dispersion curves from ambient seismic noise Muhumuza, Kenneth 2019 https://dx.doi.org/10.48550/arxiv.1910.10767 https://arxiv.org/abs/1910.10767 unknown arXiv arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Geophysics physics.geo-ph Applied Physics physics.app-ph FOS Physical sciences Article CreativeWork article Preprint 2019 ftdatacite https://doi.org/10.48550/arxiv.1910.10767 2022-03-10T16:26:40Z 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. Inter-annual 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. : 21 pages, 7 figures Article in Journal/Newspaper Antarc* Antarctica Bransfield Strait Southern Ocean West Antarctica DataCite Metadata Store (German National Library of Science and Technology) Bransfield Strait Southern Ocean West Antarctica |
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DataCite Metadata Store (German National Library of Science and Technology) |
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topic |
Geophysics physics.geo-ph Applied Physics physics.app-ph FOS Physical sciences |
spellingShingle |
Geophysics physics.geo-ph Applied Physics physics.app-ph FOS Physical sciences Muhumuza, Kenneth A feasibility study on monitoring crustal structure variations by direct comparison of surface wave dispersion curves from ambient seismic noise |
topic_facet |
Geophysics physics.geo-ph Applied Physics physics.app-ph FOS Physical sciences |
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. Inter-annual 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. : 21 pages, 7 figures |
format |
Article in Journal/Newspaper |
author |
Muhumuza, Kenneth |
author_facet |
Muhumuza, Kenneth |
author_sort |
Muhumuza, Kenneth |
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 |
arXiv |
publishDate |
2019 |
url |
https://dx.doi.org/10.48550/arxiv.1910.10767 https://arxiv.org/abs/1910.10767 |
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_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1910.10767 |
_version_ |
1766145909006008320 |