The Gravitational Signature of Earthquakes
The Gravitational Signature of Earthquakes
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DOI：
10.1007/978-3-662-04827-6_34
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
R. Gross;B. Chao
中科院分区：
文献类型：
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作者：
R. Gross;B. Chao
地震产生的静态位移场会重新分配地球的质量，从而引起地球自转和全球引力场的变化。尽管过去已经对地震对地球自转和全球引力场的同震效应进行了模拟，但还没有对这种效应进行明确的观察。然而，计划于2001年发射的重力恢复和气候实验(GRACE)卫星将以前所未有的精度高度和有序地测量地球引力场的时间变化。在这里，将模拟地震对地球全球引力场的同震效应，并与GRACE测量的预期精度进行比较。结果表明，1960年智利或1964年阿拉斯加大地震等大地震的同震效应可以引起全球引力场的变化，这些变化大到足以被Grace探测到。然而，过去35年中发生的最大地震的同震效应导致了全球引力场的变化，这些变化可能太小，Grace无法检测到。
The static displacement field generated by an earthquake redistributes the Earth’s mass and consequently causes the Earth’s rotation and global gravitational field to change. Although the coseismic effect of earthquakes on the Earth’s rotation and global gravitational field has been modeled in the past, no unambiguous observations of this effect have yet been made. However, the Gravity Recovery And Climate Experiment (GRACE) satellite, which is scheduled to be launched in 2001, will measure time variations of the Earth’s gravitational field to high degree and order with unprecedented accuracy. Here, the coseismic effect of earthquakes on the Earth’s global gravitational field will be modeled and compared with the expected accuracy of the GRACE measurements. It is shown that the coseismic effects of great earthquakes such as the 1960 Chilean or 1964 Alaskan events can cause global gravitational field changes that are large enough to be detected by GRACE. However, the coseismic effects of the largest earthquakes that have occurred during the past 35 years cause global gravitational field changes that are probably too small to be detected by GRACE.