Use of Shannon Information Entropy in Earthquake Nowcasting

Earthquake nowcasting uses cumulative counts of interevent small earthquakes (say, 3.0≤M<6.0) between successive large earthquakes (M≥6.0) to estimate the current dynamic state of a geological fault system. As Shannon information entropy (SIE) can suitably quantify the amount of information preserved in a dataset, the present study implements the concept of SIE to the earthquake fault system to examine its efficacy in the computation of earthquake potential score (EPS). The EPS provides a unique measure to determine the current level of earthquake cycle progression in a defined area. Earthquake data from a large region in Southeast Asia is considered for illustration. A comparison of EPS obtained from conventional natural-time analysis and SIE-based natural time analysis shows that SIE has minor contribution in seismic nowcasting analysis.