• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of geodynamics >Scientific achievements from the first phase (1997-2003) of the Global Geodynamics Project using a worldwide network of superconducting gravimeters
【24h】

Scientific achievements from the first phase (1997-2003) of the Global Geodynamics Project using a worldwide network of superconducting gravimeters

机译：使用全球超导重力仪网络开展的全球地球动力学项目第一阶段（1997-2003年）的科学成果

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper aims to review the main scientific achievements which were obtained in the first phase (1997-2003) of the Global Geodynamics Project (GGP) consisting of a worldwide network of superconducting gravimeters (SG) of about 20 instruments. We show that the low noise levels reached by these instruments in various frequency bands allow us either to investigate new signals of very small amplitude or to better determine other signals previously seen. We first report new results in the long-period seismic band with special emphasis on the detection of the _2S_1 normal mode and the splitting of the fundamental spheroidal mode _2S_0 after the magnitude 8.4 Peru earthquake in 2001. We also discuss briefly the 'hum', which consists of a sequence of fundamental normal modes existing between 2 and 7 mHz even in the lack of any seismic excitation, and was first discovered on the Syowa (in Antarctica) instrument in 1998. We will comment on the search for the Slichter mode _1S_1 of degree 1 which is associated with a translational motion of the inner core inside the liquid core. Atmospheric effects are reviewed from the local to the global scale and the improvement due to pressure loading computations on residual gravity signals is shown. An interesting study exhibiting the gravity consequence due to sudden rainfall and vertical mass motion in the atmosphere (without ground pressure change) is presented. The precision of the SGs leads to some convincing results in the tidal domain, concerning the fluid core resonance effect (free core nutation (FCN)) on diurnal tides or various loading effects (linear, non-linear) from the oceans. In particular, SGs gravity measurements are shown to be useful validating tools for ocean tides, especially if they are small and/or confined to coastal regions. The low instrumental drift of the SGs also permits to investigate non-tidal effects in time-varying gravity, especially of annual periodicity. Hydrology has also a signature which can be seen in SG measurements as shown by several recent studies. At even lower frequency, there is the Chandler motion of 435-day period which leads to observable gravity changes at the Earth's surface. We finally report on the progress done in the last years in the problem of calibrating/validating space satellite data with SG surface gravity measurements.
机译：本文旨在回顾在全球地球动力学项目（GGP）的第一阶段（1997-2003年）中获得的主要科学成就，该项目由全球约20台仪器组成的超导重力仪（SG）网络组成。我们表明，这些仪器在各个频带中达到的低噪声水平使我们可以研究幅度非常小的新信号，也可以更好地确定先前看到的其他信号。我们首先报告长周期地震带的新结果，特别着重于2001年秘鲁8.4级地震后_2S_1正模的检测和基本球体模_2S_0的分裂。我们还简要讨论了“嗡嗡声”，它由即使在没有任何地震激发的情况下也存在于2至7 mHz之间的一系列基本法向模式组成，并且于1998年首次在Syowa（南极洲）仪器上发现。我们将对搜索Slichter模式_1S_1进行评论程度1的变化与内芯在液芯内部的平移运动有关。从本地到全球范围对大气影响进行了回顾，并显示了由于对残余重力信号进行压力加载计算而产生的改善。提出了一项有趣的研究，该研究展示了由于突然降雨和大气中的垂直质量运动（无地面压力变化）引起的重力结果。 SGs的精度在潮汐域中产生了一些令人信服的结果，涉及流体芯对日潮的共振效应（自由芯体章动（FCN））或来自海洋的各种载荷效应（线性，非线性）。特别是，SGs重力测量显示出是验证海洋潮汐的有用工具，尤其是当它们较小和/或仅限于沿海地区时。 SGs的低仪器漂移也允许研究随时间变化的重力，特别是年度周期性的非潮汐影响。最近的一些研究表明，水文学也具有标志性，可以在SG测量中看到。在更低的频率下，有435天的钱德勒运动，这会导致地球表面的引力变化。我们最终报告了最近几年在利用SG表面重力测量来校准/验证空间卫星数据方面所取得的进展。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号