@article{oai:nipr.repo.nii.ac.jp:00010096,
 author = {Doi, Koichiro and Shibuya, Kazuo and Wendt, Anja and Dietrich, Reinhard and King, Matt and Doi, Koichiro and Shibuya, Kazuo and Wendt, Anja and Dietrich, Reinhard and King, Matt},
 issue = {1},
 journal = {Polar science, Polar science},
 month = {Jun},
 note = {In 1969, prior to the discovery of the subglacial Lake Vostok, an Askania Gs-11 gravimeter was operated at Vostok Station (78.466°S, 106.832°E; 3478 m asl) to observe tidal gravity variations. To gain a better understanding of the lake's tidal dynamics, we reanalyzed these data using a Bayesian Tidal Analysis Program Grouping method (BAYTAP-G and -L programs). The obtained phase leads for the semidiurnal waves M2 (6.6 ± 2.1°) and S2 (10.1 ± 4.2°) are more pronounced than those of the diurnal waves, among which the largest phase lead (for K1) was 5.0 ± 0.5°. The obtained δ factor for M2 was 0.890 ± 0.032, significantly less than the theoretical value of 1.16. For three global ocean tide models (NAO99b, FES2004, and TPXO6.2), the estimated load tides on waves Q1, O1, P1, K1, M2, and S2 range from 0.1–0.2 μGal (Q1 and S2) to 0.6–0.7 μGal (K1). The difference in amplitude among the three models is less than 0.14 μGal (M2), and the difference in phase is generally less than 10°. In calculating the residual tide vectors using the ocean models, the TPXO6.2 model generally gave the smallest residual amplitudes. Our result for the K1 wave was anomalously large (1.36 ± 0.25 μGal), while that for the M2 wave was sufficiently small (0.37 ± 0.17 μGal). The associated uncertainty is half that reported in previous studies. It is interesting that the residual K1 tide is approximately 90° phase-leaded, while the M2 tide is approximately 180° phase-leaded (delayed). Importantly, a similar reanalysis of data collected at Asuka Station (71.5°S, 24.1°E) gave residual tides within 0.2–0.3 μGal for all major diurnal and semidiurnal waves, including the K1 wave. Therefore, the anomalous K1 residual tide observed at Vostok Station must be linked to the existence of the subglacial lake and the nature of solid–ice–water dynamics in the region., 1969年にアスカニアGs-11重力計よる観測がVostok基地で実施された。その後、氷床下湖Vostok湖が発見され、湖の潮汐によるダイナミクスを解明するために、そのデータを潮汐解析プログラムBAYTAP-Gを使って再解析した。得られた半日周潮の位相進みは日周潮のそれよりも明瞭であった。また、M2分潮のδファクターは理論値よりも有意に小さかった。3つの海洋潮汐モデルで荷重潮汐の補正を行ったところ、K1分潮の残差(1.36±0.25μGal)は極めて大きかったが、全体の解析誤差は以前の結果の半分に減少していた。Asuka基地での過去のデータに対する同様の再解析では、K1分潮も含めた主要な日周、半日周潮で残差が0.3μGal以内であり、両者の違いは重要な意味を持つ。},
 pages = {1--12},
 title = {Tidal gravity variations revisited at Vostok Station, Antarctica},
 volume = {3},
 year = {2009}
}