The Chilean quake of 1960 shook the entire Earth for many days, a phenomenon called oscillation that was measured by seismic stations around the planet.
1960年的智力地震让地球持续震动了若干天。持续的震动被各地的地震观测站测量到。
2
The angular difference between the astronomical axis and the axis of figure called a "nutation" causes an earth orbit al spirical oscillation known as the famous chandler "wobble".
在天文学轴和形状轴之间的角度差称做“章动”，引起地球轨道螺旋摆动，就是著名的卡南德尔“摆动”。
3
The earth free oscillation can be used to constrain structure of the earth interior, including velocity, discontinuity as well as density distribution.