A case study of detecting the triplet of 3S1 using superconducting gravimeter records with an alternative data preprocessing technique
Item
Title (Dublin Core)
A case study of detecting the triplet of 3S1 using superconducting gravimeter records with an alternative data preprocessing technique
Description (Dublin Core)
Due to their very low noise levels in the low frequency band (<1 mHz), superconducting gravimeters (SGs) are particularly suitable to observe long-period free oscillations of the Earth. This case study is dedicated to the detection of the triplet of the seismic normal mode <sub>3</sub>S<sub>1</sub> that was excited by the December 26, 2004, Sumatra-Andaman earthquake (Mw = 9.3). Some SG records and the Hilbert-Huang transformation are used as an alternative data preprocessing technique, instead of the traditional detiding method. After removal of atmospheric pressure effects from the original SG records, we applied the Hilbert-Huang transformation to the SG residues, to select the signals that included the frequency band of interest, and to construct a new data series. Then, by applying the multi-station experimental technique to five 273-h-long common new data series recorded at different SG stations, we clearly observed all of the three singlets of the mode <sub>3</sub>S<sub>1</sub>, with the central singlet more evident compared to previous studies. Observations of the low-frequency modes <sub>3</sub>S<sub>1</sub> (n = 0, 1, 2, ...; l = = 1,2, ...) provide constraints on the inner and outer core structure. This case study provides an alternative data-preprocessing approach to observe the splitting frequencies of the low-frequency mode type <sub>3</sub>S<sub>1</sub> (n = 0, 1, 2, ...).<br />
Creator (Dublin Core)
Wen-Bin Shen
Bo Wu
Subject (Dublin Core)
Seismic normal mode
Superconducting gravimeters data
Hilbert-Huang transformation
Multi-station experiment
3S1 triplet
Meteorology. Climatology
QC851-999
Geophysics. Cosmic physics
QC801-809
Publisher (Dublin Core)
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Date (Dublin Core)
2012-06-01T00:00:00Z
Type (Dublin Core)
article
Identifier (Dublin Core)
1593-5213
2037-416X
10.4401/ag-4944
https://doaj.org/article/50f2efc8231844dc81f8514f33191bc9
Source (Dublin Core)
Annals of Geophysics, Vol 55, Iss 2 (2012)
Language (Dublin Core)
EN
Relation (Dublin Core)
http://www.annalsofgeophysics.eu/index.php/annals/article/view/4944
https://doaj.org/toc/1593-5213
https://doaj.org/toc/2037-416X
Provenance (Dublin Core)
Journal Licence: CC BY