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Parameters of the fluid core resonance inferred from superconducting gravimeter data

Sato, Tadahiro; Tamura, Yoshiaki; Matsumoto, Koji; Imanishi, Yuichi; McQueen, Herbert

Description

We have estimated the parameters of fluid core resonance (FCR) due to the nearly diurnal free wobble of the Earth's core based on the superconducting gravimeter (SG) data obtained at the following four observation sites; Esashi and Matsushiro in Japan, Canberra in Australia and Membach in Belgium. By fitting the tidal admittances normalized with the O1 wave at each site to a model of the damped harmonic oscillator, we obtained values of 429.66 ± 1.43 sidereal days, 9350-10,835, -4.828E-4 ±...[Show more]

dc.contributor.authorSato, Tadahiro
dc.contributor.authorTamura, Yoshiaki
dc.contributor.authorMatsumoto, Koji
dc.contributor.authorImanishi, Yuichi
dc.contributor.authorMcQueen, Herbert
dc.date.accessioned2015-12-13T22:45:04Z
dc.date.available2015-12-13T22:45:04Z
dc.identifier.issn0264-3707
dc.identifier.urihttp://hdl.handle.net/1885/79586
dc.description.abstractWe have estimated the parameters of fluid core resonance (FCR) due to the nearly diurnal free wobble of the Earth's core based on the superconducting gravimeter (SG) data obtained at the following four observation sites; Esashi and Matsushiro in Japan, Canberra in Australia and Membach in Belgium. By fitting the tidal admittances normalized with the O1 wave at each site to a model of the damped harmonic oscillator, we obtained values of 429.66 ± 1.43 sidereal days, 9350-10,835, -4.828E-4 ± 3.4E-6, -3.0E-5 ± 4.5E-6 for the eigenperiod, the Q-value and the real and imaginary parts of the resonance strength, respectively. Our values obtained from only using the gravity data are very consistent with those inferred from the VLBI nutation data. Our study strongly indicates that the systematic difference between two estimations from the gravity and the nutation in particular for the Q-value, which has been shown in previous works, is mainly caused by the inaccurate correction for the ocean tide effects. The error in the ocean tide correction is discussed based on the comparison among four global ocean tide models; Schwiderski model (1980), NAO.99b (Matsumoto et al., 2000), CSR4.0 (Eanes and Bettadpur, 1994) and GOT99.2b (Ray, 1999).
dc.publisherPergamon-Elsevier Ltd
dc.sourceJournal of Geodynamics
dc.titleParameters of the fluid core resonance inferred from superconducting gravimeter data
dc.typeJournal article
local.description.notesImported from ARIES
local.description.refereedYes
local.identifier.citationvolume38
dc.date.issued2004
local.identifier.absfor040405 - Gravimetrics
local.identifier.ariespublicationMigratedxPub7994
local.type.statusPublished Version
local.contributor.affiliationSato, Tadahiro, National Astronomical Observatory of Japan
local.contributor.affiliationTamura, Yoshiaki, National Astronomical Observatory of Japan
local.contributor.affiliationMatsumoto, Koji, National Astronomical Observatory of Japan
local.contributor.affiliationImanishi, Yuichi, University of Tokyo
local.contributor.affiliationMcQueen, Herbert, College of Physical and Mathematical Sciences, ANU
local.bibliographicCitation.startpage375
local.bibliographicCitation.lastpage389
local.identifier.doi10.1016/j.jog.2004.07.016
dc.date.updated2015-12-11T10:19:24Z
local.identifier.scopusID2-s2.0-8744316825
CollectionsANU Research Publications

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