利用JCZ-1T地震计LP通道数据检测斐济M W 8.2深震激发的地球自由振荡

JCZ-1T地震计LP通道数据可有效应用于地球自由振荡信号探测。利用泰安基准地震台JCZ-1T地震计LP通道120小时数据记录，获得2018年8月19日斐济M_W 8.2深源地震激发的地球自由振荡，检测到基频球型振荡₀S₆-₀S₅₈几乎所有振型、球型振荡部分零级振型和高振型以及环形振荡部分基振型和高振型，与地球初步参考模型（PREM）的理论自由振荡周期进行对比，结果表明，振荡周期观测值与PREM理论值基本一致，二者微小差值应由地球介质的横向不均匀性和各向异性所致。

Detection of Earth's free oscillation excited by Fiji MW 8.2 earthquake using observations of the LP channels of JCZ-1T seismometer

Observations of the LP channels of JCZ-1T seismometer are usable for detection of Earth's free oscillation. Using the 120 hours length data of LP channels of JCZ-1T seismometer at Taian Fiducial Seismic Station, we obtained the Earth's free oscillation excited by the Fiji M_W 8.2 earthquake. We extract almost all the spheroidal mode of ₀S₆-₀S₅₈, together with a portion of zero order modes, higher modes of spheroidal mode, base modes and higher modes of toroidal mode. It is shown that our results are almost consistent with the frequency of the modes of preliminary reference earth model (PREM). The inconsistent modes of spheroidal and toroidal free oscillation may result from the lateral heterogeneous and anisotropic media of the earth.