Data of continuous records of low-frequency (periods from 2 to 1,000 min) seismic noise on a global network of 229 broadband stations located around the world for 23 years, 1997–2019, are analyzed. The daily values of the entropy of the distribution of the squares of the orthogonal wavelet coefficients are considered as an informative characteristic of noise. An auxiliary network of 50 reference points is introduced, the positions of which are determined from the clustering of station positions. For each reference point, a time series is calculated, consisting of 8,400 samples with a time step of 1 day, the values of which are determined as the medians of the entropy values at the five nearest stations that are operable during the given day. The introduction of a system of reference points makes it possible to estimate temporal and spatial changes in the correlation of noise entropy values around the world. Estimation in an annual sliding time window revealed a time interval from mid-2002 to mid-2003, when there was an abrupt change in the properties of global noise and an intensive increase in both average entropy correlations and spatial correlation scales began. This trend continues until the end of 2019, and it is interpreted as a feature of seismic noise which is connected with an increase in the intensity of the strongest earthquakes, which began with the Sumatran mega-earthquake of December 26, 2004 (M = 9.3). The values of the correlation function between the logarithm of the released seismic energy and the bursts of coherence between length of day and the entropy of seismic noise in the annual time window indicate the delay in the release of seismic energy relative to the coherence maxima. This lag is interpreted as a manifestation of the triggering effect of the irregular rotation of the Earth on the increase in global seismic hazard.

分析了1997年至2019年23年间在全球229个宽带站的全球网络上连续记录的低频（2至1,000分钟）低频地震噪声的数据。正交小波系数的平方的分布的熵的日值被认为是噪声的信息特征。引入了一个由50个参考点组成的辅助网络，其位置由站点位置的聚类确定。对于每个参考点，将计算一个时间序列，该序列由8400个样本组成，时间步长为1天，其值确定为给定日期内五个可操作的最近站点的熵值的中值。参考点系统的引入使得可以估计世界各地的噪声熵值的相关性的时间和空间变化。在年度滑动时间窗口中的估计揭示了从2002年中到2003年中的时间间隔，那时全球噪声的性质发生了突然的变化，并且平均熵相关性和空间相关性尺度都开始急剧增加。这种趋势一直持续到2019年底，这被解释为地震噪声的一个特征，与最强烈的地震强度的增加有关，这始于2004年12月26日的苏门答腊特大地震（当全局噪声的特性突然发生变化，并且平均熵相关性和空间相关性尺度都开始急剧增加时。这种趋势一直持续到2019年底，这被解释为地震噪声的一个特征，与最强烈的地震强度的增加有关，这始于2004年12月26日的苏门答腊特大地震（当全球噪声的性质突然发生变化，并且平均熵相关性和空间相关性尺度都开始急剧增加时。这种趋势一直持续到2019年底，这被解释为地震噪声的一个特征，与最强烈的地震强度的增加有关，这始于2004年12月26日的苏门答腊特大地震（中号= 9.3）。在每年的时间窗口中，释放的地震能量的对数与日长之间的相干爆发和地震噪声的熵之间的相关函数值指示相对于相干最大值的地震能量释放的延迟。这种滞后被解释为地球不规则旋转对全球地震危险性增加的触发作用的体现。