We first report that the seismic time-sequence data from around the world, excluding major earthquakes, consistently yield the power spectral density inversely proportional to the frequency f. This is the 1/f fluctuation that appears ubiquitously in nature. We investigate the origin of this 1/f fluctuation based on our recent proposal: 1/f noise is amplitude modulation and demodulation. We hypothesize that the amplitude modulation is linked to resonance with Earth’s Free Oscillations (EFO), with demodulation occurring during fault ruptures. We provide partial validation of this hypothesis through an analysis of EFO eigenmodes. Additionally, we outline potential methods for the future verification of our theory relating 1/f fluctuations to EFO.

中文翻译：

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调幅地球自由振荡引起的地震 1/f 波动

我们首先报告说，来自世界各地的地震时间序列数据（不包括大地震）始终产生与频率f成反比的功率谱密度。这就是自然界中普遍存在的1/ f涨落。我们根据我们最近的提议研究了这种 1/ f波动的起源：1/ f噪声是幅度调制和解调。我们假设振幅调制与地球自由振荡（EFO）的共振有关，在断层破裂期间发生解调。我们通过 EFO 特征模态分析来部分验证这一假设。此外，我们概述了未来验证我们的 1/ f波动与 EFO 相关理论的潜在方法。