Detection of hidden earthquakes after the 2011 Tohoku earthquake by automatic hypocenter determination combined with machine learning

Earth, Planets and Space

Table 2 Comparison of the results of Tamaribuchi and Nakagawa (2020), abbreviated TN20, before and after the application of the phase classifier in this study

(a) TP and FP indicate the numbers of events that do and do not coincide with the JMA unified catalog, respectively. Quality labels A–D are the results of our LightGBM quality control label classifier. (b) Residuals between events in the JMA unified catalog and their corresponding automatically determined hypocenters. μ and σ are the mean and standard deviation, respectively. Subscripts x, y, D, and M indicate longitude, latitude, depth, and magnitude, respectively