On the wobbles of phase-velocity dispersion curves
SUMMARY To calculate phase-velocity dispersion curves, we introduce a method which reflects both structural and dynamic effects of wave propagation and interference. Rayleigh-wave fundamental-mode surface waves from the South Atlantic Ocean earthquake of 19 August 2016, M = 7.4, observed at the AlpA...
Published in: | Geophysical Journal International |
---|---|
Main Authors: | , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Oxford University Press (OUP)
2020
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1093/gji/ggaa487 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa487/33865528/ggaa487.pdf http://academic.oup.com/gji/article-pdf/224/3/1477/34834202/ggaa487.pdf |
id |
croxfordunivpr:10.1093/gji/ggaa487 |
---|---|
record_format |
openpolar |
spelling |
croxfordunivpr:10.1093/gji/ggaa487 2024-01-28T10:09:10+01:00 On the wobbles of phase-velocity dispersion curves Kolínský, Petr Bokelmann, Götz Austrian Science Fund 2020 http://dx.doi.org/10.1093/gji/ggaa487 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa487/33865528/ggaa487.pdf http://academic.oup.com/gji/article-pdf/224/3/1477/34834202/ggaa487.pdf en eng Oxford University Press (OUP) http://creativecommons.org/licenses/by/4.0/ Geophysical Journal International volume 224, issue 3, page 1477-1504 ISSN 0956-540X 1365-246X Geochemistry and Petrology Geophysics journal-article 2020 croxfordunivpr https://doi.org/10.1093/gji/ggaa487 2023-12-29T09:23:46Z SUMMARY To calculate phase-velocity dispersion curves, we introduce a method which reflects both structural and dynamic effects of wave propagation and interference. Rayleigh-wave fundamental-mode surface waves from the South Atlantic Ocean earthquake of 19 August 2016, M = 7.4, observed at the AlpArray network in Europe are strongly influenced by the upper-mantle low-velocity zone under the Cameroon Volcanic Line in Central Africa. Predicting phase-delay times affected by diffraction from this heterogeneity for each station gives phase velocities as they would be determined using the classical two-station method as well as the advanced array-beamforming method. Synthetics from these two methods are thus compared with measurements. We show how the dynamic phase velocity differs from the structural phase velocity, how these differences evolve in space and how two-station and array measurements are affected. In principle, arrays are affected with the same uncertainty as the two-station measurements. The dynamic effects can be several times larger than the error caused by the unknown arrival angle in case of the two-station method. The non-planarity of the waves and its relation to the arrival angle and dynamic phase-velocity deviations is discussed. Our study is complemented by extensive review of literature related to the surface wave phase-velocity measurement of the last 120 years. Article in Journal/Newspaper South Atlantic Ocean Oxford University Press (via Crossref) Geophysical Journal International 224 3 1477 1504 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Geochemistry and Petrology Geophysics |
spellingShingle |
Geochemistry and Petrology Geophysics Kolínský, Petr Bokelmann, Götz On the wobbles of phase-velocity dispersion curves |
topic_facet |
Geochemistry and Petrology Geophysics |
description |
SUMMARY To calculate phase-velocity dispersion curves, we introduce a method which reflects both structural and dynamic effects of wave propagation and interference. Rayleigh-wave fundamental-mode surface waves from the South Atlantic Ocean earthquake of 19 August 2016, M = 7.4, observed at the AlpArray network in Europe are strongly influenced by the upper-mantle low-velocity zone under the Cameroon Volcanic Line in Central Africa. Predicting phase-delay times affected by diffraction from this heterogeneity for each station gives phase velocities as they would be determined using the classical two-station method as well as the advanced array-beamforming method. Synthetics from these two methods are thus compared with measurements. We show how the dynamic phase velocity differs from the structural phase velocity, how these differences evolve in space and how two-station and array measurements are affected. In principle, arrays are affected with the same uncertainty as the two-station measurements. The dynamic effects can be several times larger than the error caused by the unknown arrival angle in case of the two-station method. The non-planarity of the waves and its relation to the arrival angle and dynamic phase-velocity deviations is discussed. Our study is complemented by extensive review of literature related to the surface wave phase-velocity measurement of the last 120 years. |
author2 |
Austrian Science Fund |
format |
Article in Journal/Newspaper |
author |
Kolínský, Petr Bokelmann, Götz |
author_facet |
Kolínský, Petr Bokelmann, Götz |
author_sort |
Kolínský, Petr |
title |
On the wobbles of phase-velocity dispersion curves |
title_short |
On the wobbles of phase-velocity dispersion curves |
title_full |
On the wobbles of phase-velocity dispersion curves |
title_fullStr |
On the wobbles of phase-velocity dispersion curves |
title_full_unstemmed |
On the wobbles of phase-velocity dispersion curves |
title_sort |
on the wobbles of phase-velocity dispersion curves |
publisher |
Oxford University Press (OUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1093/gji/ggaa487 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa487/33865528/ggaa487.pdf http://academic.oup.com/gji/article-pdf/224/3/1477/34834202/ggaa487.pdf |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Geophysical Journal International volume 224, issue 3, page 1477-1504 ISSN 0956-540X 1365-246X |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1093/gji/ggaa487 |
container_title |
Geophysical Journal International |
container_volume |
224 |
container_issue |
3 |
container_start_page |
1477 |
op_container_end_page |
1504 |
_version_ |
1789338848498548736 |