Research on Dynamics of Earth's Deep Interior by Employing a Superconducting Gravimeter Network in Northern and Southern Hemispheres

利用超导重力仪（SG）进行精密重力测量有望成为探测由地球流体核振荡或由于区域构造运动引起的长期重力变化引起的非常微弱的信号的有效措施。全球地球动力学计划（GGP）是在IUGG和IAG的赞助下建立的一个全球性的SG网络，该计划是一个观测地球重力场时间变化的国际计划。该网络的数据分发始于1997年。关于全球SG网络，我们的研究小组为扩大北方和南半球的网络做出了贡献。目前，我们已在江藏、松代、京都、阿索、昭和（南极）、堪培拉（澳大利亚）、万隆（印度）和新奥勒松（挪威）进行了SG观测。近三年来，我们观测到了日潮带的流体核共振、与极移有关的长周期重力变化以及地球自由振荡的不断激发。此外，SG和FG-5绝对重力仪的同步观测发现了海潮的负荷效应。

Precise gravity measurements using superconducting gravimeters (SGs) are expected to be an effective measure for detection of very weak signals caused by oscillations in the Earth's fluid core, or long-term gravity changes due to regional tectonic movements. A global network of SGs was set up by Global Geodynamic Project (GGP), an international program of observations of temporal variations in the Earth's gravity field, under the sponsorship of IUGG and IAG. Data distribution of the network began in 1997. With regard to the global network of SGs, our research group has contributed to extend the network in northern and southern hemispheres. Nowadays, we have carried on SG observations in Esashi, Matsushiro, Kyoto, Aso, Syowa (Antarctica), Canberra (Australia), Bandung (Indoesia) and Ny-Alesund (Norway). During recent three years, we observed fluid core resonance in diurnal tidal bands, long-period gravity changes related to the polar motion, as well as incessant excitation of the Earth's free oscillations. Furthermore, simultaneous observations of SGs and FG-5 Absolute Gravimeters detected the loading effects of ocean tides.