Detection of Long-Range Correlations and Trends Between Earthquakes in California

In this paper, we investigate the long-range correlations and trends betweenconsecutive earthquakes by means of the scaling parameter so-called locally Hurstparameter, H(t), and examine its variations in time, to find a specific pattern thatexists between Earthquakes. The long-range correlations are usaully detectedby calculating a constant Hurst parameter. However, the multi-fractal structure ofearthquakes caused that more than one scaling exponent is needed to accountfor the scaling properties of such processes. Thus, in this paper, we consider thetime-dependent Hurst exponent to realize scale variations in trend and correlationsbetween consecutive seismic activities, for all times. We apply the Hilbert-Huangtransform to estimate H(t) for the time series extracted from seismic activitiesoccurred in California during ۱۲ years, from ۲/۲۴/۲۰۰۷ to ۹/۲۹/۲۰۱۷. The superiorityof the method is discovering some specific hidden patterns that exist betweenconsecutive earthquakes, by studying the trend and variations of H(t). EstimationgH(t) only as a measure of dependency, may lead to misleading results, but using thismethod, the trend and variations of the parameter is studying to discover hiddendependencies between consecutive earthquakes. Recognizing such dependencypatterns can help us in prediction of future main shocks.

Keywords:

Long-range dependence , Time-dependent Hurst exponent , Hilbert-Huang transform , Empirical Mode Decomposition , Seismic activities