Counts of occurrence per depth in 富山県（Toyama Pref.）

Counts of occurrence per depth in 富山県（Toyama Pref.）is shown as below graph,  

Most earthquakes occurred near the border between 長野県（Nagano Pref.) and 岐阜県（Gifu Pref.) . Especially,  the continuing earthquakes in 1998 are accounts for 75% of all depths. The 3rd longest silent term of 30km between 1962-1993 seems to the sign of the longest one of 20km. Furthermore, the one of 20km between 1976 -1977 seems to be the sign of the the continuing earthquakes in 1998. The latest rapid increase of 20km was induced by M7.6 Noto Peninsula Earthquake in 2024. The effects for other depths are not so much.  

• 1km (red)…The count is the 1st. 1km was increasing steadily before 1998. There was the rapid increase of both 1km/10km curves by the continuing earthquake near the border between 長野県（Nagano Pref.) and 岐阜県（Gifu Pref.) in 1998. The earthquakes both in 長野県 and 岐阜県 are accounts for 75% of all depths in this 富山県 area. For about 10 years after it, 1km curve was overtaken by 10km curve temporary. There was the rapid increase induced by M9.0 Great East Japan in 2011, and 1km overtook 10km curve. After it, there were 2 additional rapid increases, and 1km curve has kept the top occurrence. The largest one of 1km is M5.6 on the way of the continuing earthquake in 1998.
• 10km(yellow)…The count is the 2nd. 10 km curve was following behind 1km curve. There were 2 major rapid increases common with 1km both in 1998/2020. Especially, the one in 1998 was very rapid, and overtook 1km curve for about 10 years temporary as described above. The largest one of 10km is M5.1 in 1936.      
•  20km(orange)…The count is the 3rd. After 1935, 20km was following behind 10km curve. But, by the rapid increase of 10km in 1998, the distance of the curves between 10km and 20km became by far. Before the rapid increase of 10km, there was the longest silent term between 1976-1977. It may be the sign of the rapid increase of 1km/10km caused by the continuing earthquake in 1998. Then, there were the 2 time long silent terms of 20km. One was the 2nd longest between 2001-2017. The other was between 2017-2024. The later one was broken by the aftershocks of M7.6 Noto Peninsula Earthquake in 2024. The latest rapid increase of 20km was induced by the M7.6 in 2024. The largest one of 10km is M5.1 in 1970. 
• 30km(orange)…The count is the 4th, and the count is only 3 times. After the long silent term between 1919-1936. The next one was the 4th length between 1936-1962. The continuing one was the 3rd between 1962-1993. The 3rd one of 30km seems to induce the 1st longest one of 20km between 1976-1977 as the sign of the continuing earthquake in 1998. The last one of 20km is the 1st length extending since 1993. The largest one of 30km is M4.5 in 1936.
• others…omitted.