自1998年以来,在陆地系统中检测到大规模的质量再分配
Christopher M Cox1, Benjamin F Chao
1Raytheon Information Technology and Scientific Services (ITSS), Space Geodesy Branch, NASA Goddard Space Flight Center, Code 926, Greenbelt, MD 20771, USA.
Science (New York, N.Y.)
|August 6, 2002
概括
地球的平坦度 (J2) 意外地在1998年左右从下降转变为增加. 这种由不确定的地质物理原因驱动的全球质量分布的变化,现在掩盖了冰期后反弹的影响.
科学领域:
- 地质物理学 地质物理学
- 地球科学 地球科学 地球科学
- 地质测量是指地质测量.
背景情况:
- 地球的动态平坦度 (J2) 显示了25年的下降趋势,这是由于后冰期的反弹.
- 大约在1998年,人们观察到J2增长趋势的突然逆转.
- 最近这种增长的地质物理驱动因素仍然不确定.
研究的目的:
- 分析地球平度 (J2) 趋势的变化.
- 调查全球质量分布变化的影响.
- 了解所观察到的J2增长背后的地质物理原因.
主要方法:
- 过去25年来太空地质观测的分析.
- 地理物理建模以评估质量再分配.
- 来自不同来源的J2效应的比较.
主要成果:
- 观察到1998年左右的J2趋势出现了显著的逆转.
- 目前的J2增长趋势主要是由全球质量分布的变化驱动的.
- 来自当前质量再分配的J2效应的大小明显超过了来自地幔反弹的影响.
结论:
- 最近地球平坦度的增加 (J2) 表明全球质量分布的实质性变化.
- 这种转变的地质物理原因需要进一步调查.
- 当前质量再分配对J2的影响比后冰期反弹更为主导.
相关概念视频
01:23Mass Spectrum
A mass spectrum is the graphical representation of the relative abundance of the charged fragments in an analyte plotted against their mass-to-charge ratio (m/z). The plot's x-axis represents the ratio of the mass of the charged fragment to the number of charges it carries. The y axis of the plot represents the relative abundance of each charged species. The relative abundance is calculated from the signal intensity of each charged species recorded at the detector. The most intense signal (the...
01:05Gravimetry: Overview
Gravimetric analysis is a quantitative method where the analyte is isolated and weighed directly or after conversion into a substance of known composition. Gravimetric analysis can be classified as precipitation, electrogravimetry, volatilization, and particulate gravimetry, based on the method used to isolate the analyte.
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...