International Collaboration on the Study of Geodynamics of Subglacial Lake Vostok, Antarctica

1969年，施耐德(1970年)在沃斯托克站(78.466°S，东经106.832°，海拔3478m)使用了Askania Gs-11型重力仪。我们用BAYTAP-G和-L(Tamura等人，1991年)程序重新访问和分析了数据。对于NAO99b(MatSumoto et al.，1999)和FES99(Lefevre et al.，2000)的两个全球海洋潮汐模型，我们估计了负荷潮汐。K1波的剩余幅度为1.91±0.25uGal，M2波的剩余幅度为1.24uGal±0.14uGal。K1波的剩余幅度为1.91uGal，M2波的剩余幅度为1.24uGal。μ。与Dietrich等人的结果相比，相关的不确定度减少到三分之一。(2001年)。有趣的是，K1波约为900相超前，而M2波约为1800相超前(延迟)。重力变化到垂直位移的转换系数为-0.29Gal/mm，位移在±10 mm的范围内，与2002年/2003年季节实际观测的μ垂直运动在最小二乘意义上一致。湖面上方的气压差导致了气压表的反差效应，由此产生的高度变化从几天到几周的时间尺度上高达40毫米。通过2002/2003年夏季对南湖的差动GPS观测，可以验证这种影响以及差动潮汐运动。测量到的最大分量的幅度和相位对应于微分平衡潮汐的各自值。利用1996年的4幅ERS-1/-2串联干涉图分析了地表位移的空间分布规律。这些测量显示了一个凸起，带有一个幅度不同但几何形状相似的宽阔的潮汐挠曲带。此外，可以得出结论，湖内相关的水重新分配形成了湖内整体水循环的一个额外组成部分。

In 1969, an Askania Gs-11 gravimeter was operated at Vostok Station (78.466°S, 106.832°E, 3478 m asl) by Schneider (1970). We revisited and analyzed the data with a BAYTAP-G and -L (Tamura et al., 1991) program. For the two global ocean tide models of NAO99b (Matsumoto et al., 1999) and FES99 (Lefevre et al., 2000), we estimated the load tides. For the K1 wave, the obtained residual amplitude was 1.91 ± 0.25μ Gal, while for the M2 wave it was 1.24 ± 0.14,u Gal. The associated uncertainty reduced to one-thirds as compared with the results by Dietrich et al. (2001). It is interesting that K1 wave is about 900 phase-leaded, while M2 wave is about 1800 phase-leaded (delayed). With a conversion coefficient of -0.29μ Gal/mm from gravity variation to vertical displacement, the displacement was in the range of about ±10 mm ; which is found to match the actually observed 2002/2003-season GPS vertical motion in a least square sense. Air pressure differences above the lake cause a differential inverse barometer effect with resulting height changes of up to 40 mm on time scales from days to weeks. The effect could be verified, together with the differential tidal motions, by differential GPS observations in the southern part of the lake during the 2002/2003 summer season. The measured amplitudes and phases of the largest constituents correspond to the respective values of the differential equilibrium tides. Four ERS-1/-2 tandem interferograms of 1996 were used to analyze the spatial pattern of the surface displacement. These measurements reveal a bulge with a wide tidal flexure zone of varying amplitude but a similar geometry. Moreover, it can be concluded that the associated water redistribution within the lake forms an additional component of the overall water circulation in the lake