Fig. 10

a Monthly and cumulative numbers of earthquake events in the K-NET and KiK-net data archive up to the end of 2019. The histogram and line represent the monthly and cumulative numbers, respectively. b Monthly and cumulative numbers of the strong motion records in the K-NET and KiK-net data archives. The red, blue, and black lines represent the cumulative numbers of records for K-NET, KiK-net, and their total, respectively. c Temporal distribution of PGA in the K-NET and KiK-net data archives. The red, green, and black lines represent the PGA values of 2000 cm/s/s or larger, 1000 cm/s/s or larger but lower than 2000 cm/s/s, and lower than 1000 cm/s/s, respectively. N and n denote the numbers of earthquakes and the records satisfying the criterion, respectively. d Temporal distribution of PGV in the K-NET and KiK-net data archives. The red, green, and black lines represent the PGV values of 100 cm/s or larger, 50 cm/s or larger but lower than 100 cm/s, and lower than 50 cm/s, respectively. N and n denote the numbers of earthquakes and the records satisfying the criterion, respectively. e Temporal distribution of the JMA seismic intensity (Ijma) in the K-NET and KiK-net data archives. Red, green, and black lines represent Ijma 6.5 or larger, 5.5 or larger but lower than 6.5, and lower than 5.5, respectively. N and n denote the numbers of earthquakes and the records satisfying the criterion, respectively