Counts of occurrence per depth in 根室地方南部

Counts of occurrence per depth in 根室地方南部 (South Nemuro region) is shown as below graph, 

1km (red)…This count of the earthquakes is the 1st one. All of them are unknown details (with no magnitude data). The increase stopped after the longest silent term between 1982 - 1994. 

10km…No occurrence.

20km(Orange)… Only once with no magnitude data in 1966.

30km…No occurrence. 

40km(green)… Only 3 earthquakes (8th). The max magnitude is M5.7 in 1928, and this is also the max in all depth. M5.7 was occurred after many unknown details of 1km.

50km(light blue) …This count was the 2nd. Since M5.6 in 1952, the count has been kept the 2nd. M5.6 is the 2nd strength in all depth.

60km(blue) …This count was the 7th less than 100km(6th). The max magnitude is M4.2 in 1973.   

70km (violet)…The count is the 3rd. 2000s and after, the curve chased each other with 90km. Though the count is higher than 90km, 70km stopped in 2022 earlier than 90km. The max magnitude is M4.1 in 1991/1994.  

80km (navy blue)…The count is the 5th. The max magnitude is M4.5 in 2012.  

90km (brown)…The count is the 4th. The max magnitude is M5.4 in 2018.

Others… omitted.

Only 1km has stood out from other depths. The most of earthquakes in this area may be occurred in 50-90km for a while. In 10-40km, there are only few earthquakes recently.