【摘要】 用垂直摆倾斜仪和水管倾斜仪的数字化观测资料,利用功率谱密度估计方法,在没有对资料进行去固体潮处理的情况下,准确获得了2008年5月12日汶川8.0级大地震激发的0S6～0S32基频球型自由振荡。并与PREM模型的理论自由振荡周期进行了对比,发现实测振荡周期与PREM预测的振荡周期相吻合,除0S7振型的观测周期和PREM模型理论周期的相对误差大于0.3%外,其他振型的观测周期和PREM模型理论周期的相对误差大都集中在0.1%左右。可以从垂直摆倾斜仪和水管倾斜仪的观测资料中提取汶川地震激发的地球球型振荡信息,这为地球自由振荡的研究提供了一种新的仪器观测方法。用数字化地倾斜观测资料研究地球自由振荡问题或许有着较好的前景。更多还原

【Abstract】 Based on the digital observatory data of pendulum tilt-meter and water tube tilt-meter,spheroidal modes of earth’s free oscillations,induced by the M_S8.0 Wenchuan strong earthquake occurred on May 12,2008,was obtained with the method of power spectral density estimation without any calculation to erase solid tide.The result matches well with the PREM’s when it is compared with the theoretical free oscillation of PREM model with the exception of ₀S₇,and the relative errors that are mostly bigger than 0.3%.All other relative errors concentrate on 0.1%.This research provides a new method to get spheroidal modes of earth’s free oscillations from observatory data of pendulum tilt-meter and water tube tilt-meter,which may be useful in the future of the earth’s free oscillations research.更多还原