Observations of the Singlets of Higher-Degree Modes Based on the OSE

Shi-Yu Zeng; Wen-Bin Shen

doi:10.1007/s12583-017-0810-0

Volume 29 Issue 6

Nov 2018

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Journal of Earth Science > 2018 > 29(6): 1398-1408.

Shi-Yu Zeng, Wen-Bin Shen. Observations of the Singlets of Higher-Degree Modes Based on the OSE. Journal of Earth Science, 2018, 29(6): 1398-1408. doi: 10.1007/s12583-017-0810-0

Citation:

Shi-Yu Zeng, Wen-Bin Shen. Observations of the Singlets of Higher-Degree Modes Based on the OSE. Journal of Earth Science, 2018, 29(6): 1398-1408. doi: 10.1007/s12583-017-0810-0

Shi-Yu Zeng, Wen-Bin Shen. Observations of the Singlets of Higher-Degree Modes Based on the OSE. Journal of Earth Science, 2018, 29(6): 1398-1408. doi: 10.1007/s12583-017-0810-0

Citation:

Shi-Yu Zeng, Wen-Bin Shen. Observations of the Singlets of Higher-Degree Modes Based on the OSE. Journal of Earth Science, 2018, 29(6): 1398-1408. doi: 10.1007/s12583-017-0810-0

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Observations of the Singlets of Higher-Degree Modes Based on the OSE

doi: 10.1007/s12583-017-0810-0

Shi-Yu Zeng¹,
Wen-Bin Shen^{1,2
,
,}

1.
School of Geodesy and Geomatics/Key Laboratory of the Geospace Environment and Geodesy, Wuhan University, Wuhan 430079, China
2.
State Key Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China

More Information

Corresponding author: Wen-Bin Shen
Received Date: 09 May 2017
Accepted Date: 16 Oct 2017
Publish Date: 01 Dec 2018

Abstract

Abstract

In this study, we selected 18 SG (superconducting gravimeter) records from 15 GGP stations with 99 vertical and 69 horizontal components of IRIS broad-band seismograms during 2004 Sumatra Earthquake to detect the splitting of higher-degree Earth's free oscillations modes (₀S₄, ₀S₇~₀S₁₀, ₂S₄, ₁S₅, ₂S₅, ₁S₆) and 12 inner-core sensitive modes (₂₅S₂, ₂₇S₂, ₆S₃, ₉S₃, ₁₃S₃, ₁₅S₃, 1₁S₄, ₁₈S₄, ₈S₅, 1₁S₅, ₂₃S₅, ₁₆S₆) by using OSE (optimal sequence estimation) method which only considers self-coupling. Results indicate that OSE can completely isolate singlets of high-degree modes in time-domain, effectively resolve the coupled multiplets independently, and reduce the possibility of mode mixing and end effect, showing that OSE could improve some signals' signal-to-noise ratio. Comparing the results of SG records with seismic data sets suggests that the number of SG records is inadequate to detect all singlets of higher modes. Hence we mainly selected plentiful seismograms of IRIS to observe the multiplets of higher modes. We estimate frequencies of the singlets using AR method and evaluate the measurement error using bootstrap method. Besides, we compared the observa-tions with the predictions of PREM-tidal model. This study demonstrates that OSE is effective in isolating singlets of Earth's free oscillations with higher modes. The experimental results may provide constraints to the construction of 3D Earth model.
- free oscillation,
- mode splitting detection,
- high-degree modes,
- OSE

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References(54)

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