MD-T chart in 北海道東方沖

MD-T chart in 北海道東方沖(East offshore Hokkaido region) 

  

MD chart in 北海道東方沖

MD chart  in 北海道東方沖(East offshore Hokkaido region) 

 

Dragon chart in 北海道東方沖

Dragon chart in 北海道東方沖(East offshore Hokkaido region) 

    

Sum of Magnitude per 1day in 北海道東方沖

Sum of Magnitude per 1day in 北海道東方沖(East offshore Hokkaido region) 

note : Horizontal axis isn't linear.
 

Distribution of Magnitude in 北海道東方沖

Distribution of Magnitude in 北海道東方沖(East offshore Hokkaido region) 

   

Distribution of Depth in 北海道東方沖

Distribution of Depth in 北海道東方沖(East offshore Hokkaido region) 

 

Area map of 北海道東方沖

Area map of 北海道東方沖(East offshore Hokkaido region) is defined for epicenter's analysis as below, 

 

Counts of occurrence per depth in 択捉島付近

 Counts of occurrence per depth in 択捉島付近(Etorofu Island)  is shown as below graph, 

Only 1km stands out from others. On the other hand, 100km and deeper ones are high ranks of the counts. Especially, 100km stands out from others except 1km.   Such case is rare. In general, deeper ones are less than shallow ones. It seems  there could be around M7 of 40km or 30km (or both) in several years. Recent curves have steeper slopes.    

1km(red)…This count of the earthquakes is the 1st. The longest silent term was between 1937-1954. 4 years later, M6.7 was occurred in 1958 (M6.7 is the greatest one of 1km). By this M6.7, the count increased rapidly.  After several steps, there was the 2nd longest silent term between 1989-2001. Just before the end of it, there was M6.9 of 30km in 2001. Since 2008, the slope becomes steep. The the largest magnitude in this depth is M5.9 in 1979.   

100km(gray)…The count is the 2nd since M7.2 in 1978. The M7.2 is the greatest one of all depth. Then, the curve follows 1km still now. 5 depths of more than 100km are within top 10 of counts. The count of 100km is less than half of 1km. 

120km(gray)…The count is the 3rd. The the largest magnitude in this depth is M6.6 in 1945. The count of 100km is less than 1/3 of 1km. 

80km(navy)…The count is the 3rd as same as 120km. The the largest magnitude in this depth is M6.4 in 1962. 

90km(brown)…The count is the 5th. After M6.1 in 1938, there was the longest silent term between 1938-1978. About 6 months later, M7.2 of 100km was occurred in 1978. After several steps, there was the 3rd longest silent term between 1989 - 2003 (2nd was between 1919- 1938).  Before 2 years ago from the end of it, there was M6.9 of 30km in 2001.  Since 2011, the slope becomes steep. The largest magnitude in this depth is M6.1 in 1938. 

40km(green)…The count is the 5th as same as 90km. There was the 2nd longest silent term between 1939-1968. Then, the slope became steep. After M7.2 of 100km 1978, it became steeper. In 1982, M6.8 was occurred as the greatest one of 40km. Since the M6.8, there was the longest silent term between 1984 - 2021. It could be around M7 or so on in several years.

150km&160km(gray)…The count is the 5th as same as 90km/40km. The largest magnitude in this depth is M5.7 in 2002(150km)/M6.2 in 1985(160km). 

30km(light green)…The count is the 9th as same as 130km/140km. The count difference between 40km is only 4 times. The largest magnitude in this depth is M6.9 in 2001. 

130km&140km(gray)…The count is the 9th as same as 30km.  The largest magnitude in this depth is M5.7 in 1928(130km)/M6.3 in 1941(140km).  

others…omitted     

MD-T chart in 択捉島付近

MD-T chart in 択捉島付近(Etorofu Island)   

 

MD chart in 択捉島付近

MD chart in 択捉島付近(Etorofu Island)   

 

Dragon chart in 択捉島付近

Dragon chart in 択捉島付近(Etorofu Island)    

Sum of Magnitude per 1day in 択捉島付近

Sum of Magnitude per 1day in 択捉島付近(Etorofu Island)

note : Horizontal axis isn't linear.
 

Distribution of Magnitude in 択捉島付近

 Distribution of Magnitude in 択捉島付近(Etorofu Island)   

Distribution of Depth in 択捉島付近

Distribution of Depth in 択捉島付近(Etorofu Island)   

Area map of 択捉島付近

Area map of 択捉島付近(Etorofu Island) is defined for epicenter's analysis as below, 

 

Counts of occurrence per depth in 国後島付近

Counts of occurrence per depth in 国後島付近 (Kunashiri Island)  is shown as below graph, 

Only 1km's count has been stood out. On the other hand, the other shallow 10km/20km's counts are very low. The curves except 1km/50km were jammed around M6.9 of 30km in 1980. As same as it, the curves except 1km/10km/30-50km were also jammed around M7.2 of 100km in 1978. 

• 1km(red)…This count of the earthquakes is the 1st. Before M5.4 in 1924, all of 1km were "unknown details" with no data of the magnitude. 7 months later  from M5.4, M6.9 was occurred in 1925. Both M6.9 of 1km in 1925/of 30km in 1968 are the 2nd greatest in all depths (The 1st was M7.2 of 100km in 1978). The longest silent term is continuing since 1994 after the 2nd one between 1982-1994. The 1km earthquakes occurred in 1994 were aftershocks of M8.2 (Hokkaido East offshore Earthquake). The epicenter (of 30km) was out of this area.
• 50km(light blue)…The count is the 2nd since 1955. Recently, 50km is the most active depth. The the largest magnitude in this depth is M5.9 in 1979.  
  
• 40km(green)…The count is the 3rd. 40km curve had overlapped with 30km since M6.7 in 1964. But, there was a rapid increase by M8.2 (Hokkaido East offshore Earthquake) in 1994. After the aftershocks of 40km, there was a long silent term 1994-2005. Then, the count has started the increase again after it. The largest magnitude in this depth is M6.7 in 1964.  
  
• 70km(purple)…The count is the 4th. The curves of 70km/60km is overtaken and being overtaken. The largest magnitude in this depth is M5.7 in 1994.  
  
• 80km(navy)…The count is the 5th. The curve almost stays between 70km and 90km. Before M8.2 (Hokkaido East offshore Earthquake) of 30km in 1994, there had been the rapid slope of 90km between 1992-1994. After M8.2, the rapid slope was taken over by 80km. In recent years, the curve is approaching 70km. The largest magnitude in this depth is M6.3 in 1994.  
  
• 60km(blue)…The count is the 6th. The curves of 60km/70km is overtaken and being overtaken. The largest magnitude in this depth is M5.7 in 1994.   After around 2010, the silent term has the tendency of becoming longer. So, 70km/80km curves overtook 60km. As the silent terms became longer since 2010,  the count rank became lower. The largest magnitude in this depth is M6.2 in 1929.  
  
• 30km(yellow green)…The count is the 7th. Though the curves of 30km/40km was overtaken and being overtaken, no significant increase of the count wasn't occurred after M8.2 (Hokkaido East offshore Earthquake) in 1994. On addition to it, there was the longest silent term between between 1995-2013.  The largest magnitude in this depth is M6.9 in 1968. As the value is large, the count should become greater than now in future.
• 90km(brown)…The count is the 8th(100km's curve is the 9th). Though the curve was following 80km until M7.2 of 100km in 1965, it was delayed from 80km after the M7.2. The largest magnitude in this depth is M5.9 in 1957. 
• 20km(orange)…The count is the 10th. There were 2 times major rapid increases after both M6.9 of 30km in 1980 and M6.8 of 30km in 1980.  After the long silent term between 1987-2011, the count has been accelerated. The largest magnitude in this depth is M6.3 in 2018.
• 10km(yellow)…The count is the 11th. As same as 20km, this shallow 10km is also low rank of counts. The longest silent term of 10km is continuing since 1995. The largest magnitude in this depth is M5.6 in 1934. The value is less than 20km's largest value of M6.3. So, the update may be still far in the future.
• Others…omitted. 

MD-T chart in 国後島付近

MD-T chart in 国後島付近 (Kunashiri Island) 

 

MD chart in 国後島付近

MD chart in 国後島付近 (Kunashiri Island) 

Dragon chart in 国後島付近

Dragon chart in 国後島付近 (Kunashiri Island) 

 

Sum of Magnitude per 1day in 国後島付近

Sum of Magnitude per 1day in 国後島付近 (Kunashiri Island)  is defined for epicenter's analysis as below, 

note : Horizontal axis isn't linear.
 

Distribution of Magnitude in 国後島付近

Distribution of Magnitude in 国後島付近 (Kunashiri Island) 

 

Distribution of Depth in 国後島付近

Distribution of Depth in 国後島付近 (Kunashiri Island) 

Area map of 国後島付近

Area map of 国後島付近 (Kunashiri Island) is defined for epicenter's analysis as below, 

Counts of occurrence per depth in 北海道北西沖

Counts of occurrence per depth in 北海道北西沖 (Northwest offshore Hokkaido region) is shown as below graph, 

All 3 earthquakes more than M6.0 were occurred in deeper than 230km. M4.8 is the max in 1km-60km. 

• 1km (Red)…This count of the earthquakes is the 1st. Before M4.5 in 1965, all of 1km were "unknown details" with no data of the magnitude. The M4.5 is the largest one in this depth.
• 10km(yellow)…The count is the 2nd. There was a longest silent term between 1919-1993. In late 2010s, the count increased with 20km rapidly, and it overtook 20km's one. It may also overtake 1km's one in near future. The the largest magnitude in this depth is M3.7 in 2024.
  
• 20km(orange)…The count is the 3rd. There was a longest silent term between 1919-1968. In late 2010s, the count increased with 10km rapidly. The the largest magnitude in this depth is M4.8 in 2013.
• 30km(light green)…The count is the 4th. There was a longest silent term between 1956-1996. The the largest magnitude in this depth is M4.6 in 2016. 
  
• 40km(green)…There was only once as M4.3 in 1978.
• 50km… No occurrence
• 60km(blue) … There was only once in 1952. But, the magnitude is unknown.
• Others…There are few in 240km-330km. But, all 3 earthquakes more than M6.0 were occurred in these depth as shown in the chart above.
  

MD-T chart in 北海道北西沖

MD-T chart in 北海道北西沖 (Northwest offshore Hokkaido region)

 

MD chart in 北海道北西沖

MD chart in 北海道北西沖 (Northwest offshore Hokkaido region)

 

Dragon chart in 北海道北西沖

Dragon chart in 北海道北西沖 (Northwest offshore Hokkaido region)

 

Sum of Magnitude per 1day in 北海道北西沖

Area map of 北海道北西沖 (Northwest offshore Hokkaido region)  is defined for epicenter's analysis as below,  

note : Horizontal axis isn't linear.
 

Distribution of Magnitude in 北海道北西沖

Distribution of Magnitude in 北海道北西沖 (Northwest offshore Hokkaido region)

 

Distribution of Depth in 北海道北西沖

Distribution of Depth in 北海道北西沖 (Northwest offshore Hokkaido region)

Area map of 北海道北西沖

Area map of 北海道北西沖 (Northwest offshore Hokkaido region) is defined for epicenter's analysis as below, 

Counts of occurrence per depth in 北海道西方沖

Counts of occurrence per depth in 北海道西方沖 (West offshore Hokkaido region) is shown as below graph,

Most earthquakes have been occurred in 1km/10km. As the max of all depth is M7.5 of 1km in 1940, the earthquake greater than M7.5 (or near M7.5) may be occurred in future as the combination of rapid increases among 1km, and other depth(10km, 20km, or so on). But, there is no sign of it except the long silent term of 20km since 2006.

• 1km (Red)…This count of the earthquakes is the 1st one. Just before M7.5 in 1940, there was a long silent term between 1938-1940. Before M7.5, all of 1km were "unknown details" with no data of the magnitude. M7.5 is the largest one in all depth. After M7.5 until M6.7 in 1947, all of 1km except M5.9 in 1943 were also "unknown details". Before M6.7, there was no other depth earthquake except both M5.5 of 280km in 1945 and unknown magnitude of 10km in 1946. By M6.7, there was not only a rapid increase of 1km, but also the first 30km,40km,50km&70km within one month. Then, the silent term of 1km became longer and longer. After the long silent term between 1953-1958, M6.2 was occurred in 1959. After the aftershocks, the silent term of 1km became further longer. The longest silent term of 1km was occurred between 1968-1982. This term of 1km overlapped with the 2nd longest silent term of 10km between 1961-1983. Then, the silent terms became shorter and shorter especially after M6.1 of 10km in 2004. Recently, the silent terms is becoming longer gradually. The max magnitude of 1km is M7.5 in 1940.  
  
• 10km (yellow)…The count is the 2nd. The first one was in 1946 just 1 year go of M7.5 of 1km in 1940. So, it seems to be the sign before the M7.5 even unknown magnitude. The longest silent term is between 1919-1946 until it. The max magnitude of 10km is M6.1 in 2004. The max magnitude of 10km is M6.1 in 2004.
• 20km (orange)…The count is the 3rd. But, it is still only 5 times. The last occurrence was M4.0 in 2006. The max magnitude of 20km is M5.9 in 1995.
• Others…The counts are only 0-2 times. The max magnitude of them is M6.1 of 270km in 2016.
  

MD-T chart in 北海道西方沖

MD-T chart in 北海道西方沖 (West offshore Hokkaido region) 

MD chart in 北海道西方沖

MD chart in 北海道西方沖 (West offshore Hokkaido region)  

Dragon chart in 北海道西方沖

Dragon chart in 北海道南西沖 (Southwest offshore Hokkaido region)  

Sum of Magnitude per 1day in 北海道西方沖

Sum of Magnitude per 1day in 北海道西方沖 (West offshore Hokkaido region) 

note : Horizontal axis isn't linear.

Distribution of Magnitude in 北海道西方沖

Distribution of Magnitude in 北海道西方沖 (West offshore Hokkaido region) 

Distribution of Depth in 北海道西方沖

Distribution of Depth in 北海道西方沖 (West offshore Hokkaido region) 

Area map of 北海道西方沖

Area map of 北海道西方沖 (West offshore Hokkaido region) is defined for epicenter's analysis as below,  

Counts of occurrence per depth in 北海道南西沖

Counts of occurrence per depth in 北海道南西沖 (Southwest offshore Hokkaido region)  is shown as below graph, 

According with the wider domino effect of depth range, the magnitudes become greater from M6.1 in 1950, M7.1 in 1982, and M8.3 in 1993.

10km (yellow)…This count of the earthquakes is the 1st one. 10km&20km curves has chased each other back and forth. Recently, 10km is more than 20km. There was a  rapid increase of 10km caused by M6.1 in 1950 after the longest silent term between 1929 - 1950. The 2nd step up was caused by M7.1 in 1983 after the 2nd longest silent term between 1967 - 1983. The 3rd step up was caused by M7.8 of 40km in 1993. The rapid increase of 10km after M7.8 was delayed from the ones of 40km/30km/20km/1km. It seems to show the domino effect of earthquakes of M7.8 should have been carried over from the epicenter of 40km to shallower depth. The max magnitude of 10km is M7.1 in 1983.

20km(orange)…This count was the 2nd overtaken by 10km recently. The 1st step up was caused by M6.1 of 10km in 1950 delayed from 10km after the 2nd longest silent term between 1930 - 1953 of 20km. The 2nd step up was caused by M7.1 of 10km in 1983 after the longest silent term between 1966 - 1983. The 3rd step up was was caused by M7.8 in 1993. M6.3 of 20km was also caused M7.8. This  M6.3 is the max magnitude of 20km.

30km(light green)…This count was the 3rd. After the longest silent term between 1942 - 1966, there were 2 long silent terms between 1966 - 1977 / 1977-1983. After them, there was the rapid increase of 30km in 1983 was caused by M7.1 of 10km. The 2nd increase was caused by M7.8 of 40km in 1993.  In result, 30km has overtaken 1km. The max magnitude of 30km is M6.0 in 1983 caused by M7.8. 

40km(green)…This count was the 4th. After the longest silent term between 1933 - 1967 , M7.8 was occurred in 1993 as the end period of 2nd longest silent term since 1967. The M7.8 in 1993 became the origin of domino effect from 40km to 1km. M7.1 of 10km in 1983 had the smaller domino effect from 30km to 1km. The difference from M7.1 to M7.8 seems to be the difference of the depth ranges, not only the one of the length of fault (The deeper cut should have the wider aperture area). M6.1 of 10km in 1950 had the further smaller domino effect from 10km to 1km. 

50km(light blue)…This count was the 5th. After long silent terms, only 2 earthquakes were occurred just after M7.8 of 40km in 1993 as 4th & 5th of the total count of 50km additionally.

Others … M6.4s were occurred of 240km in 1981 / of 250km in 1996 as outstanding ones.  

 

MD-T chart in 北海道南西沖

MD-T chart in 北海道南西沖 (Southwest offshore Hokkaido region)  

MD chart in 北海道南西沖

MD chart in 北海道南西沖 (Southwest offshore Hokkaido region) 

 

Dragon chart in 北海道南西沖

 Dragon chart in 北海道南西沖 (Southwest offshore Hokkaido region)  

Sum of Magnitude per 1day in 北海道南西沖

Sum of Magnitude per 1day  in 北海道南西沖 (Southwest offshore Hokkaido region) 

note : Horizontal axis isn't linear.
 

Distribution of Magnitude in 北海道南西沖

Distribution of Magnitude in 北海道南西沖 (Southwest offshore Hokkaido region) 

 

Distribution of Depth in 北海道南西沖

Distribution of Depth in 北海道南西沖 (Southwest offshore Hokkaido region)  

Area map of 北海道南西沖

 Area map of 北海道南西沖 (Southwest offshore Hokkaido region) is defined for epicenter's analysis as below, 

 

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.　

MD-T chart in 根室地方南部

MD-T chart  in 根室地方南部 (South Nemuro region) 

 

MD chart in 根室地方南部

 MD chart in 根室地方南部 (South Nemuro region)