A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise
Author
Source
International Journal of Geophysics
Issue
Vol. 2020, Issue 2020 (31 Dec. 2020), pp.1-11, 11 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2020-02-03
Country of Publication
Egypt
No. of Pages
11
Main Subjects
Abstract EN
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.
American Psychological Association (APA)
Muhumuza, K.. 2020. A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise. International Journal of Geophysics،Vol. 2020, no. 2020, pp.1-11.
https://search.emarefa.net/detail/BIM-1171387
Modern Language Association (MLA)
Muhumuza, K.. A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise. International Journal of Geophysics No. 2020 (2020), pp.1-11.
https://search.emarefa.net/detail/BIM-1171387
American Medical Association (AMA)
Muhumuza, K.. A Feasibility Study on Monitoring Crustal Structure Variations by Direct Comparison of Surface Wave Dispersion Curves from Ambient Seismic Noise. International Journal of Geophysics. 2020. Vol. 2020, no. 2020, pp.1-11.
https://search.emarefa.net/detail/BIM-1171387
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1171387