Analysis of M6.6+ in Hyuga Nada(日向灘) including both #SP12-2&#SP12-12 of (macro-analysis)

 [Summary] 

There are 2 special earthquakes of the 12 Singularities (#SP12-2&#SP12-12) in Hyuga Nada. For the macro analysis of them, I have syudied about M6.6+ in Hyuga Nada based on downloaded data (1919～Jan.2026) from JMA Seismic Intensity Database. The analysis showed not only  the counterclockwise loop of earthquakes similar with Case 1 (壱岐・隠岐) or Case 2 (the 12 Singularities), but also clockwise loop after the turning point. The study showed the possiility of the next M7+ as the closing point of the M7 loop around #SP12-2 on the exteded line from #SP12-12.  The next M7+ might become the trigger of Nankai Trough earthquake as M8+.

[macro-analysis] 

M7+ in Hyuga Nada area is shown as the circles inside of blue rectangular in the figure (downloaded from JMA) as below, 

The listed earthquakes of M7+ are listed with the data of the "date/time/seismic intensity/rounded longitude(E)/rounded latitude(N)/depth/ Number of Stage of M/M/elongitude(E)/rounded latitude(N)"  as the below list. The series numbers (#) are given to them as HG7-1 ～ HG7-6 (old～new). Orange colored one is M7 of #SP12-2 (HG7-3), and yellow colored one is M7.1 of #SP12-12(HG7-6). 

The 6 of M7+ in Hyuga Nada are plotted on the chart of Lng ve Lat of epicenters with the labels of each Magnitude as below,

M7 of #SP12-2 (HG7-3) is plotted as orange dot, and M7.1 of #SP12-12(HG7-6) is plotted as yellow dot. The loop of M7+ is counterclockwise(CCW) as similar with Case 1 (壱岐・隠岐) or Case 2 (the 12 Singularities),  but the loop hasn't closed. 

Characteristic of M7+ on the loop

The loop started with M7.1(HG7-1) as counterclockwise(CCW), and moved to M7.2 towards to NNE. Then, it went back with the sharp angle to M7 (#SP12-2) with CW. The next line from it to M7.5(HG7-4) formed the closed a smal closed triangle area. The red line (Southeast side) is almost parallel with the another red line (Northwest side) betweem M7.1 (HG7-5)/M7.1(#SP12-12/HG7-6). In fact, the SE side red line was drawn as the parallel line with the NW red line as the copy.   Each red line includes one of the 12 Singularities (#SP12-2/#SP12-12). 

The correlation of SE red line with HG7-1/HG7-3/HG7-4

 Please see the chart as below,

The correlation coefficient(R2) beteen the Lng(E) and Lat(N) is 0.9991 (very high value). Furthermore, there are higher R2 beteen Lng(E)/Lat(N) and M as 0.9999 /0.9996. It means the  size of these M7+ on the line are almost specified perfectly on the location of the Lng(E)/Lat(N).  

As shown with the descripions so far,  earthquakes occurrences of these should be not random ones, but  be with the predestined harmony.

Characteristic of M7+ on the loop

For the additional data, I picked up M6.6+ in Hyuga Nada (日向灘). 

The new list is as below, 

(The serial numers are updated as ##1～##13.)

The loop started with M7.1(##1) with blue lable of M6.9 as counterclockwise(CCW). The lines until M7.5(##5) with blue label are formed the small closed triangle area with sharp edges. The CCW loop continued until M6.7(##6) with yellow label. Then, the loop chnge the turning direction from CCW to CW. The new loop with CW has contined until to the end point of M6.6(##13).  

For the seeking the root cause of the turning on M6.7(##6), I added the correlation red lines with high R2 (0.9942～1) on the above figure as below,

3 red correlation lines are focuced on M6.7(yellow label) with red label. It means M6.7 is the focuced point of stress from different directions, and also the tough node common with differrent lines of big earthquake occurrences. So, I guessed the turning should have occurred on this tough point from CCW to CW.

Next, I would like to focus on the 2 red solid lines.

The red solid line with negative slope includes 4 points as correlation line with high R2 (Other lines have the high R2 among only 3 points). As explained, this line includes 2 points of the 12 Singularities (M7#SP12-2: orange dot and M7.1#SP12-12: yellow dot). Thease singularities are also the start point and the end point of the M7+loop in Hyuga Nada(日向灘). If the M7+ loop extend from M7.1#SP12-12 to(or over) M7#SP12-2, the huge closed loop will be formed, and will might mean the separation from the base plate. In result, a huge earthquake should occurr similar with "茂木ドーナツ（Mogi's Donut）" effect. 

The high R2 correlation line includng 2 singularities makes the possibility higher greatly. 

Another red solid line, with positive slope, has the perfect R2 among ##1/##5/##8 as 1. Similar with the high R2 correlation line among the M7+ plots, another high correlations there are. But, the high R2 are not between Lng/Lat vs M, but between Lng/Lat vs depth among  M7.1(HG7-1)/M7(HG7-3)/M7.5(HG7-4) in M7+ loop. 

It means Ms of the grids on the perfect correlation line shoud be fixred not only by the Lng(E)/Lat(N), but also the depth fatefully.

As dicussed above, there are multi high R2 correlation lines in Hyuga Nada. They restrict the epicenters position/M/the turning directions(CCW or CW), and seems to be never random ones.

Estimation of next M7+

In the case of the M7+ loop closing by the next M7+,  the estimated M might could be calcutated as below,

Ｍmax(N=7)=real max value (M7.5)＋log10(chain reaction lines number:7)/1.5

　　　            =7.5＋log10(7)/10≒8.1

(Based on several hypothesis as belows,

  * The released energy might be the same as all charged including the closed area, and be the total of all high R2 correlation lines which had the same energy with M7.5 (real max value in Hyuga Nada). The idea is similar with "茂木ドーナツ（Mogi's Donut)" theory.  )  

Caution

If N=6/N=5, the estimated value becomes around M8.0 anyway. But,I coudn't fix the occurrence date. So, I'm not sure if it could be tomorrow or 100 years later, or so on.

#SP12-2&12 日向灘の震源の解析(マクロ的解析)

[概要] 

２つの特異震源を含む日向灘周辺のＭ６．６以上の震源推移がこれまでの壱岐・隠岐と北伊豆地震#SP12-1の解析同様の逆時計周りの推移と途中からの時計周りを示しており、日向灘での次のＭ７以上の震源が２つの特異震源を結ぶ線上で発生、南海トラフ地震のトリガーとなる可能性を示しています。

[マクロ的解析] 

１２の特異点の震源のうち、#SP12-2及び#SP12-12の２つの震源を含む日向灘の震源域を内包する矩形エリアについて解析します。

下図は気象庁有感地震データベースでの日向灘を内包する矩形エリアでのＭ７以上の震源(1919～2026/1月)とそのリスト、震源推移図です。リストのオレンジの震源が#SP12-2の特異震源Ｍ７、黄色の震源が#SP12-12で一昨年2024年に発生した特異震源Ｍ７．1です。リストでは推移順を明確にするため、HG7-1～HG7-6の連番を付与しました。

Ｍ７以上の震源推移の特徴

震源推移図では壱岐・隠岐や#SP12-1　静岡県伊豆地方の震源の解析で見られた逆時計回りの推移がここでも確認されました。北東端のＭ７．５(HG7-4)への軌跡で最初に小さな三角形の領域を逆時計周りで閉じた後、今度は大きな四角形の領域を囲むように逆時計周りで推移しています。赤い線はＭ７．１(HG7-5)から黄色の特異震源Ｍ７．１(HG7-6)を通る北西側直線、及び、その南東側に平行線をもう一つのオレンジの特異震源(HG7-3)と北東端のＭ７．５(HG7-4)近傍を通るように引いたもので、南東側のＭ７．１(HG7-1)/Ｍ７(HG7-3)/Ｍ７．５(HG7-4)の近傍を通る直線がほぼ北西側の赤線と平行であることが分かります。

北東端Ｍ７．５を除き、規模がＭ７～Ｍ７．１と近い規模の地震が揃っているのも特徴の一つです。

南東側の赤の直線上に位置するＭ７．１(HG7-1)/Ｍ７(HG7-3)/Ｍ７．５(HG7-4)では東経vs北緯の相関が高い(0.9991)だけでなく、東経・北緯のそれぞれがMに対しての相関もそれ以上の線形性(0.9999/0.9996)があります。Mの時間や深さに対する依存は見られず、Mはほぼ完全に震源の東経・北緯位置に依存しています。

※　グラフタイトルに誤りがあり、投稿後に訂正しました。

ここまで示したように少なくとも一部の地震の発生は決して偶然ではなく、厳密なルールに基づき予定調和的に発生してると見る方が妥当と考えられます。

Ｍ６．６以上の震源推移の特徴

もう少し解析データを増やすためにＭ６．６以上の震源のリストとその震源推移図を以下に示します。

リストのオレンジと黄色の地震は１２の特異震源ですが、震源を増やしたため、##１～１３の連番を振りなおしています。そのため、ここでは##４と##１２が特異震源となります。

震源推移図のラベルは各マグネチュードで、中央やや右下のＭ６．９の青いラベルが##１で##2はＭ７．１、右斜め上の##３のＭ７．２、折り返す形で##４のＭ７、再び急角度の折り返しで##５のＭ７．５、更に急角度の折り返しで##６のＭ６．７(黄色ラベル)。ここまでの推移はこれまで見られたように逆時計回りの推移が続いています。しかし、以降の推移は反転して時計回りが最後の##１３のＭ６．６まで続いています。つまり、黄色ラベルのＭ６．７が反転ポイントとなっています。

この謎を解くためにこれらの震源の東経vs北緯の相関の高いラインを確認した結果を下図に示します。赤の実線及び点線で示した相関ラインは相関係数0.9942～1です。

逆時計周りの反転ポイントＭ６．７(黄色ラベル)では３本の相関ラインが交差しており、子の震源の場所が各方向からの応力の集中点であると同時に強固な結節点であることを示唆しており、そのために周回方向の反転がここで生じたものと推測されます。

一方、赤で示した負の傾きの赤実線は二つの特異震源を含む相関ラインは４点からなります(他のラインは３点の相関)。冒頭で示したように１２の特異震源のうちの二つの震源Ｍ７(#SP12-2:オレンジ)とＭ７．１(#SP12-12:黄色)は日向灘のＭ７以上のループにおける始点(HG7-1)と終点(HG-6)であり、これらを結ぶＭ６．６以上の高相関ラインは次のＭ７以上の地震がＭ７ループを閉じる形で始点(HG7-1)付近で発生する可能性が高い事を示唆していると推測されます。

もう一つの正の傾きの赤実線は相関係数１で先ほどのＭ７震源群中の高相関線Ｍ７．１(HG7-1)/Ｍ７(HG7-3)/Ｍ７．５(HG7-4)で東経北緯vsM で別の高い相関があったのと同様に、こちらでは東経北緯vs深さにも高相関係数があります。

<訂正・補足>

M7震源群で一部に確認された高相関は東経 vs 北緯、及び東経/北緯 vs M、

M6.6震源群で一部に確認された高相関は東経 vs 北緯、及び東経/北緯 vs 深さです。

グラフタイトル見直ししています。確認不足で申し訳ありません。 

これはライン上の震源の規模Mが東経北緯だけでなく深さに対しても厳しく制約されている事を示します。

ここまで示したように震源位置の東経北緯には(高相関係数を持つ)震源ラインが複数存在し、そこで発生する地震の規模と震源推移を制約(逆時計周りor時計周り)しており、ランダムの発生とは言えないと考えます。

冒頭で示したＭ７の推移ループが始点のＭ７(１２の特異点の２番目#SP12-2)付近で閉じた場合、「茂木ドーナツ（Mogi's Donut）」と同様にその囲まれた領域の蓄積エネルギーが放出される事、この領域での各グリッドの最大蓄積エネルギーをこの領域の最大M7.5である事、異なる方向の領域内の７本の震源ラインが各最大M7.5の蓄積エネルギーを持つ事、を仮定するとこれらの震源ラインが連動して全放出された場合の想定規模Ｍmax(N=7)は以下の試算となります。

Ｍmax(N=7)=現状の最大規模(実績値M7.5)＋log10(連動する震源ライン数)/1.5

　　　            =7.5＋log10(7)/10≒8.1

なお、N=６/N=5の場合でもＭmax(N=6/5)＝8.0となり、M8クラスの可能性を示していますが、発生時期については来年か100年後か不明です。

Case2 /Analysis of Singularity Around Izu Region - the 12 Singular Epicenters (#SP12-1 to 12)

Interpretation of the 12 Singular Epicenters (#SP12-1 to 12)

Before explaining the screening method, we must define "Stages."

• 1st Stage: The first earthquake in a grid (0.1° Lon/Lat, 1 km depth).

• 2nd Stage: The first earthquake to exceed the magnitude of the 1st stage.

• 3rd Stage: The first earthquake to exceed the magnitude of the 2nd stage.

In the JMA database, 94% of M7.0+ earthquakes are 1st stage. Cases of 2nd or 3rd stages are extremely rare (only 12 cases total). We define these 12 cases of M7.0+ occurring as 2nd or 3rd stages as the "12 Singular Epicenters."

Among these 12, two groups of three consecutive earthquakes (Blue: #SP12-4 to 6; Yellow: #SP12-8 to 10) lie almost perfectly on straight lines with correlation coefficients of 1.0 and 0.9999.

• Blue Group: Located between Urakawa-oki and Offshore of Ibaraki Pref., moving nearly North-South on the landward side of the Japan Trench (1978–1982).

• Yellow Group: Follows an interesting line including the 1995 Kobe Earthquake, the 2016 Kumamoto Earthquake, and the 2016 Fukushima M7.4.

The remaining six epicenters (Orange) form a counter-clockwise loop enclosing a triangular region, similar to the Iki-Oki(壱岐・隠岐) case. This loop started with the 1930 North Izu Earthquake (near a plate triple junction) and traveled along the Nankai Trough, Izu-Ogasawara Trench, and Japan Trench, eventually reaching the 2024 Hyuga Nada M7.1.

E-Lng vs M chart / N-Lat vs M : They shows counter-clockwise direction moving similarly.

The similarity in the singularities shown here suggests that earthquake occurrence is not random, but follows specific rules or groups. The following analysis will further deepen this conviction.

Analysis of Singularity of the 12 Singularities #SP12-1 Izu region (1930 North Izu Earthquake)

[Macro Analysis]

In the 1930 North Izu Earthquake (北伊豆地震M7.3), the magnitude within the corresponding grid (139.0°E, 35°N, depth 1 km) jumped abruptly from an initial 2nd-stage value of M3.7 to a 3rd-stage M7.3. This gap cannot be explained without considering the ripple effect (which we call the "Domino Effect") from large surrounding earthquakes.

Therefore, before the micro-analysis near the singularity, I will briefly conduct a macro-analysis of the surrounding area. The following describes the M6.7+ epicenters, their list, and the transition graph within a rectangular area including the Izu region(伊豆地方) and the 1923 Kanto Earthquake (Great Kanto Earthquake関東大震災 epicenter), based on the JMA Felt Earthquake Database.

From the 1923 Kanto Earthquake M7.9 to the subsequent Izu-Oshima Nearshore M6.8, and up to the East Off Izu Peninsula M6.7, the epicenters draw a counter-clockwise loop enclosing a large triangular area. A similar transition surrounding a counter-clockwise triangular area is also observed in the Neighberhood of Iki-Oki (壱岐・隠岐近海) and the 12 Singular Epicenter groups. Additionally, epicenters relatively close to the M7.9 event show magnitudes of M7.3, while those further away scale down slightly to the M6.7–M6.9 range.

Regarding the "stages" of each grid: the Tanzawa Earthquake (M7.3), closest to the M7.9, is the 1st stage. The North Izu Earthquake (M7.3), occurring next, is a 3rd stage rising from a 2nd-stage M3.7. This shows a process where both M7.3 events were induced by the M7.9 in a domino fashion. Furthermore, the dominoes induced a 1st stage M6.9 in Suruga Bay (near Irozaki(石廊崎)). From there, both the Izu-Oshima(伊豆大島) Nearshore M7.0 and the nearby East Off Izu Peninsula (伊豆東方沖)M6.7 were induced as 2nd stages.

In the area near Izu-Oshima(伊豆大島), magnitudes have been updated—3rd stage M6.8 in 1930, 2nd stage M7.0 in 1978, and 2nd stage M6.7 in the East Off Izu Peninsula (伊豆東方沖)—showing how the maximum M in surrounding grids increased through a domino chain within the M6.7–M7.0 range.

The initial ripple from the M7.9 to the distant M6.8 was an energy transfer where energy dispersed and accumulated in surrounding grids was concentrated like dominoes and transmitted with a time lag. The phenomenon where the loop "returns to its original scale" near M6.7 after starting from M6.8 can be seen as a visualization of the process where the energy conservation of the entire system and the stress balance within the crust reach equilibrium and stabilize. Since the M6.7 in 1980, no earthquake of M6.7 or higher has occurred in this analyzed rectangular area.

Now that the macro-process analysis of the surge from 2nd-stage M3.7 to 3rd-stage M7.3 is complete, we move to the micro-analysis of the North Izu Earthquake.

[Micro Analysis]

To confirm interactions in the vertical direction, the analysis range is expanded beyond the 1 km depth to include the vertical grid hierarchy. There are 42 total earthquakes in this grid (same Lon/Lat), with 11 at 0 km and 7 at 1 km. We begin analyzing from the shallowest 0 km layer.

After three consecutive "Unknown" (unlabeled) events, the activity moved south to M3.8. Following a yellow-labeled "Unknown," it proceeded counter-clockwise, closing a rectangular area at M3.6, then moved north clockwise to M3.2. Subsequently, the pattern shifted gently toward the southwest (blue labels).

Next, we confirmed the transition of Magnitude (M) relative to Longitude. The correlation of the three points on the red line is extremely high, with a correlation coefficient of 0.9992. This constant rate of change in magnitude accompanying longitudinal movement likely reflects the existence of an extremely homogeneous gradient in stress distribution (or friction characteristics) on the fault plane.

Next, we confirmed the transition of M relative to Latitude. These are two sets of three-point correlations on the red lines. They share the M3.6 epicenter, and the correlation coefficients for the positive/negative slopes are remarkably high at 0.9998 and 0.9985, respectively. Surprisingly, both sets consist of the same magnitude combination: M3.2, M3.6, and M3.8.

The fact that two linear epicenter groups cross and share specific magnitudes suggests that the stress field at 0 km depth—directly above the singularity—possessed a mathematically rigorous geometric structure. It marks the junction of "two different structural lines (fault systems or stress axes)." The shared M3.6 epicenter may have acted as a "fixed point" where the energy gradients of longitude and latitude perfectly coincided.

---

Analysis of the 1 km Layer (Singularity Grid)

The number of epicenters in the 1 km singularity grid is seven. The activity is concentrated in a very short period in 1930.

Similar to the 0 km layer, the 1 km layer shows a counter-clockwise loop forming a trapezoidal area. The North Izu Earthquake (M7.3) occurred near the point where the loop closed. The subsequent transition moved south-southeast, deviating significantly from the trapezoidal area. This loop can be interpreted as tracing the outline of an asperity (locked zone).

Regarding M vs. Longitude at 1 km, we confirmed two sets of highly correlated epicenter groups sharing one epicenter (unlike the single set at 0 km). The correlation coefficients are 1.0 and 0.9993. With only six epicenters having recorded magnitudes, such high correlations cannot be a coincidence.

The trajectory shows M3.6 (1st stage initial) and M3.7 (2nd stage initial), followed by M3.2 and M3.4 on a line with a correlation of 1.0, before abruptly expanding to the M7.3 North Izu Earthquake.

---

Mechanisms Near the North Izu Earthquake

The two M3.8 earthquakes (November 25 and November 26) that occurred at a depth of 0 km played a decisive role in the process of constructing the "geometric framework (outer frame)" over a 24-hour period.

1. Distinction and Roles of the Two M3.8 Events in the 0 km Layer

• 1st Event: November 25, 1930 (Previous Day) M3.8 (Depth: 0 km)

  • Role: The starting point of the "negative slope" line in the correlation diagram of the 0 km layer.

  • Significance: Approximately 24 hours before the mainshock, it placed the first "maximum load point" on the singularity grid and determined the endpoints of the North-South and East-West stress gradients.

• 2nd Event: November 26, 1930 (Day of the Event) M3.8 (Depth: 0 km)

  • Role:  The starting point of the "positive slope" line in the correlation diagram of the 0 km layer.

  • Significance: In the activity on the day of the mainshock, it placed "another maximum load point" to pair with the first M3.8 (from the previous day). This completed the outer frame of the "X-shaped cross structure (screw-tightening structure)" shown in later analyses.

2. Chronological Reorganization: Linkage from the 0 km Layer to the 1 km Layer

By distinguishing between the two M3.8 events, the dynamic process until the singularity was completed as a "singularity" has become clearer.

1. Setting the Framework (Nov 25): The M3.8 (0 km) on the previous day set one "strain boundary condition" near the surface.

2. Completion of the Diagonal Axis (Early morning, Nov 26): The M3.8 (0 km) of the day occurred, pairing with the point from the previous day, completing the geometric preparation to "sandwich" the inside of the grid.

3. Precise Convergence (Nov 26, 01:00 to before 04:00): Subsequently, hypocenters such as the M3.6 (shared hypocenter) and M3.2 occurred in "descending order of magnitude" and "symmetrically" along the axes established by the M3.8 events, completely eliminating any slack within the grid.

4. Mainshock Occurrence in the 1 km Layer (Nov 26, 04:02): Immediately after the "screw-tightening (cross structure)" in the 0 km layer was completed and the surface side became an immovable "lid," the energy's escape route was transferred to the layer 1 km below. At this point, the M7.3 (3rd stage) occurred simultaneously with the M3.8 (reference value) of the 1 km layer.

Supplementary Explanation

• Although there seems to be little numerical difference between hypocenter depths of 0 km and 1 km, the 0 km depth differs in that it acts as an <u>open end</u> for waves.

• The counter-clockwise rotation of the hypocenters is observed at both macro and micro levels, suggesting the fractal nature of earthquake characteristics.

While this analysis focused on earthquakes with a hypocenter depth of 1 km, the next analysis will cover a depth of 37 km, from which I expect to gain different insights.

Case 1/Analysis of Singularity of Neighborhood Iki-Tsushima Epicenter(壱岐・対馬近海) Group

 According to the Japan Meteorological Agency (JMA) database, there are only nine recorded earthquakes in the Neighborhood of Iki-Tsushima (壱岐・対馬近海) epicenter group, listed below in chronological order:

[Table of 9 earthquakes in Neighborhood of Iki-Tsushima(壱岐・対馬近海) ]

The term "Grid Element" refers to a small block of the hypocenter defined by Longitude (0.1° units), Latitude (0.1° units), and Depth (1 km units). The Longitude and Latitude shown on the far right of the table are the original values before rounding. (The "Number of Stage" will be explained later in other blog page).

First, the transition of the epicenters in terms of Longitude and Latitude is shown below. The labels represent the magnitude of each earthquake.

Starting from an earthquake of unknown(不明) magnitude slightly to the right of the center, the activity appears to transition in a counter-clockwise direction overall, beginning from the M3.8 event that followed a second unknown(不明) magnitude event.

The figure below highlights the epicenter group indicated by the yellow labels. These points lie on a perfectly straight line with a correlation coefficient of 1, suggesting they likely occurred along a specific fault line. What is particularly noteworthy is that the three consecutive earthquakes shown in bold in the initial table are the ones demonstrating this perfect correlation. It is statistically improbable for any three epicenters out of nine to show perfect correlation by chance; for those three to be consecutive makes the idea of a coincidence even more unnatural.

The figure below shows the transition of the remaining epicenters after excluding the M4/M3.4/M3.8 on a straight line. The result is a clean, counter-clockwise loop enclosing a triangular region.

Given that the entire epicenter group (including the yellow labels) was transitioning counter-clockwise, it can be interpreted that the activity "detoured" as it was caught by a fault. This clearly illustrates how crustal fracturing was progressing in a counter-clockwise manner in the Neighborhood Iki-Tsushima(壱岐・対馬近海) area.

This concludes the prologue intended to demonstrate that earthquakes are governed by specific rules.