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

南极洲冰下沃斯托克湖地球动力学研究国际合作

• 批准号: 14580556
• 负责人: SHIBUYA Kazuo
• 金额: $ 1.86万
• 依托单位: National Institute of Polar Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580556/
• 关键词: Lake Vostok; Synthetic Aperture Radar; Lake Tide; GPS vertical motion; Subglacial Lake; ice dynamics; Antarctica; 南極氷床; 重力潮汐; GPS; 気圧応答; NCEPデータ; 氷床動力学

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

1969年，Schneider（1970）在东方站（78.466°S，106.832°E，3478 m asl）使用了一台Askania GS-11重力仪。我们用BAYTAP-G和BAYTAP-L（Tamura等人，1991年）计划。对于NAO 99 b的两个全球海潮模型（松本等人，1999）和FES 99（Lefevre等人，2000年），我们估计负荷潮汐。K_1波残余振幅为1.91 ± 0.25μ Gal，M_2波残余振幅为1.24 ± 0.14 μ Gal。与Dietrich等人（2001年）的结果相比，相关的不确定性降低到三分之一。有趣的是，K1波约为900相位超前，而M2波约为1800相位超前（延迟）。当重力变化与垂直位移的转换系数为-0.29μ Gal/mm时，位移在±10 mm范围内，与2002/2003年GPS垂直运动实测值在最小二乘意义下吻合较好。湖面上的气压差造成了气压计的反差效应，在从几天到几周的时间尺度上，高度变化高达40毫米。2002/2003年夏季，在湖的南部的差分GPS观测的影响，可以验证，连同差分潮汐运动。测得的最大成分的振幅和相位对应于微分平衡潮汐的相应值。利用1996年的4幅ERS-1/-2串列干涉图分析了地表位移的空间分布。这些测量结果揭示了一个隆起，具有不同幅度的宽潮汐弯曲区，但具有相似的几何形状。此外，可以得出结论，湖泊内相关的水再分布形成了湖泊整体水循环的额外组成部分

项目成果

Koichiro Doi, et al.: "南極・Vostok基地において観測された重力の潮汐変位データの再解析"測地学会誌講演予稿集. 98. 191-192 (2003)

Koichiro Doi 等人：“南极洲沃斯托克站观测到的重力潮汐位移数据的重新分析”大地测量学会期刊论文集 98. 191-192 (2003)。

Anja Poetzsch: "Response of subglacial Lake Vostok, Antarctica to tidal forcing"Terra Nostra. 4. 263-264 (2003)

Anja Poetzsch：“南极洲冰下沃斯托克湖对潮汐强迫的响应”Terra Nostra。

Doi, K., Shibuya, K., Aoki, S., Yamanokuchi, T.: "Response of Lake Vostok to atmospheric pressure change"IUGG Abstract B. B20. (2003)

Doi, K.、Shibuya, K.、Aoki, S.、Yamanokuchi, T.：“东方湖对大气压力变化的响应”IUGG 摘要 B. B20。

Wendt, J., Dietrich, R., Yuskevich, A., Lukin, V., Shibuya, K.: "Geodetic observations to study ice surface deformation in the area of the Vostok core location"Terra Nostra. Vol.4. 338 (2003)

Wendt, J.、Dietrich, R.、Yuskevich, A.、Lukin, V.、Shibuya, K.：“研究东方核心位置区域冰面变形的大地测量”Terra Nostra。

Doi, K., Shibuya, K., Dietrich, R., Poetzsch, A.: "Reanalysis of the records of tidal gravity variations observed at Vostok Station"Abstracts of the Geodetic Society of Japan. No.98. 191-192 (2002)

Doi, K.、Shibuya, K.、Dietrich, R.、Poetzsch, A.：“对东方站观测到的潮汐重力变化记录的重新分析”日本大地测量学会摘要。