Xie Weiyun, Hattori Katsumi, Han Peng
Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan.
Graduate School of Science, Chiba University, Chiba 263-8522, Japan.
Entropy (Basel). 2019 Mar 5;21(3):249. doi: 10.3390/e21030249.
The Gutenberg-Richter Law describes the frequency-magnitude distribution of earthquakes. A number of studies have shown that the slope ( value) of the relationship between frequency and magnitude decreased before large earthquakes. In this paper, we investigate the temporal variation of the value off the Pacific coast of Tokachi, Hokkaido, Japan, during 1990-2014. The magnitude of completeness (Mc) in the catalog is evaluated by combining the maximum curvature (MAXC) technique and the bootstrap approach. Then, the value, and its uncertainty, is computed by using the maximum likelihood estimation. The Akaike Information Criterion (AIC) with the bootstrap approach is introduced to statistically assess the temporal variation of values and quantify the significance level. The results show a decrease in trends of the value prior to two large earthquakes (26 September 2003 (M8.0) and 11 September 2008 (M7.1)) in the analyzed area. In addition, the decrease of values shows certain statistical significance three months before the 2003 Earthquake off the Pacific coast of Tokachi (M8.0). It is concluded that the value with statistical assessment may contain potential information for future large earthquake preparation off the Pacific coast of Tokachi, Hokkaido, Japan.
古登堡-里希特定律描述了地震的频率-震级分布。大量研究表明，在大地震发生前，频率与震级之间关系的斜率（b值）会降低。在本文中，我们研究了1990年至2014年期间日本北海道十胜太平洋沿岸b值的时间变化。通过结合最大曲率（MAXC）技术和自助法来评估目录中的完备震级（Mc）。然后，使用最大似然估计来计算b值及其不确定性。引入具有自助法的赤池信息准则（AIC）来统计评估b值的时间变化并量化显著性水平。结果表明，在分析区域内的两次大地震（2003年9月26日（M8.0）和2008年9月11日（M7.1））之前，b值呈下降趋势。此外，在2003年十胜太平洋沿岸地震（M8.0）前三个月，b值的下降显示出一定的统计显著性。得出的结论是，经过统计评估的b值可能包含有关日本北海道十胜太平洋沿岸未来大地震准备的潜在信息。
