Estimating the local amplification of Rayleigh waves with regional broadband seismic arrays

Huang, Yiran

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Overview

Year:: 2023
Contributor:: Huang, Yiran (creator); Dalton, Colleen (Advisor); Brown University. Department of Earth, Environmental, and Planetary Sciences (sponsor)
Genre:: theses
Subject:: Seismology
Extent:: ii, 37 p.

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Description

Abstract:: Because of the different characteristics of seismic velocity and density sensitivity kernels for Rayleigh wave amplification and phase velocity, combining observations of surface-wave amplification with surface-wave phase could help to constrain seismic models. We are developing a new method to determine the local amplification of the Rayleigh wave on a small regional scale. The amplitudes of 20-100 s Rayleigh waves are extracted from 677 teleseismic earthquakes measured at the SVEKALAPKO, LAPNET, and ScanArray with other regional networks in Fennoscandia. We use the amplitude ratio approach (Eddy and Ekström, 2014) to isolate the receiver effect from the source, focusing, and attenuation effects. In order to separate the effects of local elastic structure from erroneous instrument response in the amplification values, we firstly use three different references to identify obviously constant and time-dependent erroneous instrument response. Then by comparing amplitudes from every two nearby stations, tinier time-dependent erroneous instrument responses will be removed. Lastly, outlier amplitude data, amplitude ratio data, and stations with larger deviations from median values are removed. Because seismic networks did not overlap in time, we force the amplification of one or more geographically adjacent station pairs from time-non-overlapping networks with the same value to get a coherent set of relative local amplification for the entire study area. The final observed local Rayleigh wave amplification factors at eight periods correlate well with some known main tectonic and geologic features and agree with two predictions from regional models in Fennoscandia.
Notes:: Thesis (Sc. M.)--Brown University, 2023

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Citation

Huang, Yiran, "Estimating the local amplification of Rayleigh waves with regional broadband seismic arrays" (2023). Earth, Environmental and Planetary Sciences Theses and Dissertations. Brown Digital Repository. Brown University Library. https://repository.library.brown.edu/studio/item/bdr:uwqa7uw2/

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Earth, Environmental and Planetary Sciences Theses and Dissertations

Theses and Dissertations for the Earth, Environmental and Planetary Sciences department.
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