Data Catalog of Earthquakes around Tohoku of Japan Area has been updated related with M7.6 in 2025/12/8

 As I noticed the skip of the catalog data around Tohoku area of Japan, I have updated one of 青森県東方沖 of Tohoku area. Because, there was M7.6 in the area 3 days ago. So, I have added the special comment to some pages related with the M7.6. 

MD-T chart in 青森県東方沖

MD-T chart in  青森県東方沖 (Eastern offshore of Aomori Pref.）

There has been much blank space in recent years. It means it may be the term for the charge of earthquake energy.

MD chart in 青森県東方沖

MD chart in 青森県東方沖 (Eastern offshore of Aomori Pref.）

Dragon chart in 青森県東方沖

Dragon chart in 青森県東方沖 (Eastern offshore of Aomori Pref.）just before M7.6 on 2025/12/8.

There are 3 characteristics as below,

• The plots of 1km/10km are on a line a slope of 1.0.⋯There has been no earthquake of 1km since 1998 in this area. There has been 10km earthquake swarm(*) of the M7.6. 
• The plots of 10km/20km/30km/70km are on a line.⋯There has been an 10km/20km/30km earthquake swarms(*) of the M7.6.
• The plots of 30km/40km/50km are on a line.⋯The M7.6 was occurred in 50km, and updated the record of 50km (M7.0 in 1971 was the old record) . There has been M4.0 and M3.9 in 40km. But, the sum isn't satisfied with my difinition for earthquake swarms(*). There has been 30km earthquake swarm(*) of the M7.6.

(*)  Earthquake swarm is defined as earthquakes per the depth within 24 hours in this case.

• 

Sum of Magnitude per 1day in 青森県東方沖

Sum of Magnitude per 1day in 青森県東方沖 (Eastern offshore of Aomori Pref.）

note : Horizontal axis isn't linear.

Distribution of Magnitude in 青森県東方沖

Area map of 青森県東方沖 (Eastern offshore of Aomori Pref.）is defined for epicenter's analysis as below,  

The plot of M7.6 (ln 7.6=0.88) is an outlier on the upside.

Distribution of Depth in 青森県東方沖 Eastern offshore of Aomori Pref.

Distribution of Depth in 青森県東方沖 (Eastern offshore of Aomori Pref.）

The center of the cracking is still around 60 km, and the drop in the graph at 10 km suggests that this area has enough capacity of the stocked energy still.

Area map of 青森県東方沖

Area map of 青森県東方沖(Eastern offshore of Aomori Pref.）is defined for epicenter's analysis as below,  

Counts of occurrence per depth in 茨城県沖

Counts of occurrence per depth in 茨城県沖 (Offshore Ibaraki Pref.） is shown as below graph,

The count of 50km is the 1st. 10km/40km/30km curves are following. The count of 1km is the 7th. The longest silent terms of 1km/10km were broken by the M9.0 The great East Japan Earthquake in 2011. They should be one of the signs of the M9.0 as same as ones in the Pacific coastal area of Eastern Japan. The aftershocks didn't only generate the triple junction  among 1km/30km/60km, but also M7.6 of 40km as the greatest one of all depths. 

• 1km(red)⋯ The count is the 7th. There was a rapid increase of the count of 1km as 21-43, as the aftershocks of M7.1, counted 28 of 40km in 1923. M7.2 became the trigger of M7.2 counted as 98 of 1km in 1924. After that, the silent terms of 1km became slightly longer. But, M7.0 of 1km made the count accelerate again since the count of 267 in 1938. The silent terms of 1km became longer dramatically since the 50km curve overtook the 1km curve, counting 485 in 1976. The longest silent term of 1km is between 1993-2011 (as counted 488-489). The end point of the longest silent term was brought about by the aftershocks of the M9.0 Great East Japan Earthquake in 2011. The similar phenomenon of the long silent term was widely observed just before the M9.0 in the Pacific coastal area of Eastern Japan. It means these long silent terms should be one of the signs of the M9.0. The largest one of 1km is M7.2 in 1924.
• 10km(yellow)⋯The count is the 2nd. 10km curve was following behind 1km curve with a similar pattern to the 1km one before the M9.0 in 2011. The silent terms of 10km became longer since the 60km curve overtook the 10km curve, around counting 165 in 1962. The longest silent term of 10km between 1996-2011 (as counted 183-184). After the M9.0, 10km curve increased far more than 1km curve. The largest one of 10km is M6.9, counted 94 of 10km in 1938.
• 20km(orange)⋯The count is the 5th. 20km curve was also following behind 1km curve  with a similar pattern to the 1km one before the M9.0 in 2011. After the M9.0, 20km curve overtook 1km curve, counted 611 of 20km in 2015. The largest one of 20km is M6.7, counted 266 in 2011.
• 30km(yellow green)⋯The count is the 4th. 30km curve is following 40km curve with relatively steady silent terms. 30km curve increased in 2011, and overtook 1km curve as counted 498 in 2011. There was a triple junction among 1km/30km/60km. The  largest one of 30km is M7.0, counted 326 in 1982.
• 40km(green)⋯The count is the 3rd.Once, 40km was overtaken by 1km curve after the M7.1 of 40km, counted 28 in 1923. But, 40km curve overtook 1km with steadily increase before and after 50km curve overtaking around 1976. Then, 40km curve is following behind 50km curve. M7.6 of 40km increased rapidly. Even though the M7.6 is the greatest one of all depths, the increase was less than the one of 50km. M7.6 counted 801 of 40km.
• 50km(light blue)⋯The count is the 1st. 50km was following behind 1km curve. After the M6.9 of 10km in 1938, the steady increase made 50km curve overtake 1km curve around 1976. 50km curve didn't only overtake 40km curve, but also 1km curve in 2011 again. The  largest one of 50km is M7.0, counted 995 in 2008.
• others⋯omitted.

Earthquake analysis discussed with AI Gemini (free ver.) [updated] Abstraction English ver. (only text) added

 I have tried the making  of a mathematical model of Earthquake potential as a image.

But, I have a lot of difficulty for the copy of the result. So, I have released it as the screen shot only in Japanese.

If you would like to see them even though the language wall, please see the links below,

https://titanquake-amature.fc2.net/blog-entry-2903.html

https://titanquake-amature.fc2.net/blog-entry-2904.html

 Geminiによる三陸沖地震ポテンシャル評価（要約） [updated]

=> English ver.(only text)

<caution> 

An AI-generated summary of the model content, simplified for easy understanding by anyone, is available at the following link. While it may be slightly overrated, it should give you a general overview of the model's concept.

The copyright of this document belongs to the author. Although AI tools were used for creation and editing, the content has been supervised and structured by the author.

The comments on the final page are generated by AI and do not represent the author's opinion.

There are currently no plans to release additional specific data analysis based on this model.

Thank you.

Best regards,

MD-T chart in 茨城県沖

MD-T chart in 茨城県沖 (Offshore Ibaraki Pref.）

MD chart in 茨城県沖

MD chart in 茨城県沖 (Offshore Ibaraki Pref.）

Dragon chart in 茨城県沖

 Dragon chart in 茨城県沖 (Offshore Ibaraki Pref.）

Sum of Magnitude per 1day in 茨城県沖

Sum of Magnitude per 1day  in 茨城県沖 (Offshore Ibaraki Pref.）

note : Horizontal axis isn't linear. 

Distribution of Magnitude in 茨城県沖

 Distribution of Magnitude in 茨城県沖 (Offshore Ibaraki Pref.）

Distribution of Depth in 茨城県沖

 Distribution of Depth in 茨城県沖 (Offshore Ibaraki Pref.）

Area map of 茨城県沖

Area map of 茨城県沖 (Offshore Ibaraki Pref.）is defined for epicenter's analysis as below,