January 14, 2026
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion
* On December 8, a magnitude (M) 7.5 earthquake occurred offshore east of Aomori Prefecture. It triggered a tsunami that reached a height of 64 cm at Kuji Port in Iwate Prefecture and 50 cm at Urakawa in Hokkaido (provisional results). The earthquake registered maximum seismic intensity 6 Upper and caused damage and injuries in Aomori Prefecture. Furthermore, it generated long-period ground motion of class 3 in Sanpachi-Kamikita, Aomori Prefecture.
* On December 2, an M5.2 earthquake occurred offshore of Kushiro (Note 1) at a depth of approximately 45 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the NW-SE direction, and occurred at the boundary between the continental and Pacific Plates.
* On December 20, an M5.4 occurred offshore southeast of Nemuro Peninsula at a depth of approximately 15 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the WNW-ESE direction.
* On December 8, an M7.5 earthquake occurred offshore east of Aomori Prefecture at a depth of approximately 55 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the WNW-ESE direction, and occurred at the boundary between the continental and Pacific Plates.
GNSS observations indicated that this event caused crustal deformation, primarily in Aomori Prefecture. At the Higashidori-2 observation point in Higashidori Village, Shimokita County, Aomori Prefecture, an eastward shift of about 9 cm and subsidence of approximately 2 cm were recorded.
The earthquake triggered a tsunami that was observed from Hokkaido to the Tohoku region. At Kuji Port in Iwate Prefecture, the tsunami reached a height of 64 cm, while at Urakawa in Hokkaido, it measured 50 cm (provisional results). Seafloor Observation Network for Earthquakes and Tsunamis along the Japan Trench (S-net) also detected these tsunamis. Based on the S-net hydrostatic pressure data, the tsunami source area was estimated to extend approximately 100 km eastward from the epicenter of the M7.5 earthquake.
According to GNSS observations, within approximately 1 month following the M7.5 quake, horizontal deformations, likely caused by postseismic activity, were primarily detected in eastern Aomori Prefecture. Notably, at the Higashidori-2 observation point, an eastward shift of about 2 cm was recorded. Additionally, this deformation also encompassed those related to the M6.9 earthquake that occurred on December 12.
On December 12, seismic activity temporarily increased following an M6.9 earthquake that occurred approximately 50 km east of the M7.5 event's epicenter. Although the number of earthquakes has decreased compared to immediately after the M7.5 quake, seismic activity continues, with 50 events with maximum seismic intensity 1 or greater recorded by December 31. The seismic activity area expanded approximately 100 km eastward from the M7.5 event's epicenter. Additionally, since the M7.5 event, shallow very-low-frequency earthquakes and tremors have been occurring in the area east of the seismic activity zone.
The M6.9 earthquake on December 12 occurred within an area where earthquakes of similar magnitudes are likely to occur successively (a successive occurrence zone). Historical examples show that when a large earthquake occurs within such a zone, there is a probability of subsequent earthquakes of similar or greater magnitudes occurring.
* On December 31, an M6.1 earthquake occurred offshore of Iwate Prefecture at a depth of approximately 30 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the WNW-ESE direction, and occurred at the boundary between the continental and Pacific Plates.
Seismic activity from the December 8th earthquake (M7.5) offshore east of Aomori Prefecture can be seen to the north, whereas to the southeast, that of the November 9 earthquake (M6.9) offshore of Sanriku can be observed.
* On December 12, an M4.9 earthquake occurred under southern Ibaraki Prefecture at a depth of approximately 50 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the NW-SE direction, and occurred at the boundary between the Philippine Sea Plate and the continental plate.
* On December 14, an M4.9 earthquake occurred offshore west of Ishikawa Prefecture (Note 2), at a depth of approximately 10 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the WNW-ESE direction. This earthquake occurred within the activity zone of the M7.6 earthquake that struck the Noto region, Ishikawa Prefecture on January 1, 2024.
There was no remarkable activity.
* On December 30, an M5.7 earthquake occurred in the ocean near Amami-Oshima Island at a depth of approximately 20 km. The focal mechanism involved normal faulting, with the tension axis oriented in the NNE-SSW direction, and occurred within the continental plate.
* There has been observed no unusual change which indicates that the possibility of occurrence of a great earthquake along the Nankai Trough has relatively risen compared to the normal time.
* On December 28, an M7.0 earthquake occurred near Taiwan at a depth of approximately 90 km. The focal mechanism involved a pressure axis oriented in the WNW-ESE direction and occurred within the Philippine Sea Plate.
This earthquake occurred in the area anticipated by the Earthquake Research Committee as prone to "moderately deep earthquakes within the subducted plate northwest of the Nansei Islands" in its "Long-Term Evaluation of Seismic Activity Under Hyuganada Sea and Surrounding Areas of the Nansei Islands Trench (Second Edition) (published March 25, 2022)." Additionally, the likelihood of such an earthquake occurring within the next 30 years is classified as Rank III (#) in the long-term evaluation, indicating the highest probability among all subduction-zone earthquakes.
* On January 6, at 10:18 AM, an M6.4 earthquake occurred in eastern Shimane
Prefecture at a depth of approximately 10 km. The focal mechanism involved
strike-slip faulting, with the pressure axis oriented in the WNW-ESE direction,
and occurred within the continental plate.
GNSS observations indicated that this was accompanied by slight crustal deformation.
From January 5, tremor activity, including an M3.3 earthquake, was detected near the epicenter. Additionally, following the M6.4 earthquake, several quakes occurred, some exceeding M5.0, notably an M5.1 event at 10:28 on January 6 and an M5.5 event at 10:37 on the same day. Between January 6 and 12, 51 earthquakes with seismic intensity 1 or greater were recorded, and seismic activity continued across a 10 km east-west span.
This earthquake occurred in the northern zone identified by the Earthquake Research Committee in its "Long-Term Evaluation of Active Faults in the Chugoku Region (First Edition)." This area is assessed as having relatively active seismic activity, even though it contains few active faults.
Near this earthquake, an M5.5 earthquake occurred six days after an M5.3 earthquake hit western Tottori Prefecture in October 1989. Furthermore, in November 1990, a sequence of earthquakes occurred in the same region: an M4.8 quake followed just one minute after an M5.1 earthquake, an M5.2 earthquake occurred two days later, and another M5.1 earthquake occurred ten days after that.
#: The probability of a subduction-zone earthquake occurring within the
next 30 years is ranked as follows: Rank III: greater than 26%, Rank II:
3% ~ 26%, Rank I: less than 3%, Rank X: unknown (an immediate earthquake
cannot be ruled out).
Note 1: The place name of the epicenter used by the JMA in its information release was "offshore southeast of Nemuro Peninsula."
Note 2: The place name of the epicenter used by the JMA in its information release was "offshore of Noto Peninsula."
Note: GNSS is a general name of a satellite positioning system such as GPS.
January 14, 2026
Earthquake Research Committee
The numbers of earthquakes by magnitude (M) in and around Japan in December 2025 are as follows.
(Reference)
The following events for the period from December 2024 until the end of November 2025 have been listed as "Major Seismic Activities" in the monthly "Evaluation of Seismic Activities."
| – Under the Hyuganada Sea | M6.6 on January 13, 2025 (Depth of approximately 35 km) |
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| – In Aizu, Fukushima Prefecture | M5.2 on January 23, 2025 (Depth of approximately 5 km) |
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| – In northern Nagano Prefecture | M5.1 on April 18, 2025 (Depth of approximately 15 km) |
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| – In the ocean near Tokara Islands | M5.3 on June 30, 2025 | ||
| – In the ocean near Tokara Islands | M5.1 on July 2, 2025 | ||
| – In the ocean near Tokara Islands | M5.6 on July 2, 2025 | ||
| – In the ocean near Tokara Islands | M5.5 on July 3, 2025 (Depth of approximately 10 km) |
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| – In the ocean near Tokara Islands | M5.4 on July 5, 2025 | ||
| – In the ocean near Tokara Islands | M4.9 on July 6, 2025 | ||
| – In the ocean near Tokara Islands | M5.5 on July 6, 2025 | ||
| – In the ocean near Tokara Islands | M5.1 on July 7, 2025 | ||
| – Offshore east of the Kamchatka Peninsula, Russia | M8.8 on July30, 2025 | ||
| – In the ocean near Tokara Islands | M4.7 on September 17, 2025 | ||
| – Offshore southeast of the Nemuro Peninsula | M5.8 on October 25, 2025 (Depth of approximately 40 km) |
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| – Offshore of Sanriku | M6.9 on November 9, 2025 (Depth of approximately 15 km) | ||
| – Aso region, Kumamoto Prefecture | M5.8 on November 25, 2025 (Depth of approximately 10 km) | ||
There is no supplementary information for Hokkaido region.
There is no supplementary information for Tohoku region.
– According to the GNSS observation, the crustal deformation different from the ordinary trend in the area extending from the western Shizuoka to the eastern Aichi Prefectures has been observed since early 2022. This change is believed to result from long-term slow slip occurring deep within the boundary between the Philippine Sea Plate and the continental plate extending from the Atsumi Peninsula to Lake Hamana. The slip center is gradually shifting from the Atsumi Peninsula toward Lake Hamana.
– "On December 14, an M4.9 earthquake occurred offshore west of Ishikawa Prefecture, at a depth of approximately 10 km. The focal mechanism involved reverse faulting, with the pressure axis oriented in the WNW-ESE direction. This earthquake occurred within the activity zone of the M7.6 earthquake that struck the Noto region, Ishikawa Prefecture on January 1, 2024.":
For information on the series of seismic events that have occurred since December 2020, please refer to "Recent Seismic Activity of the "2024 Noto Peninsula Earthquakes (Published on January 14, 2026)."
There is no supplementary information for Kinki-Chugoku-Shikoku region.
– Seismic activity surged in the ocean near Tokara Islands (near Kodakarajima Island) starting on June 21, 2025. By July 7, a total of 8 earthquakes with maximum seismic intensity 5 Lower or greater were recorded, including an M5.5 earthquake on July 3. Since July 20, both seismic activity and the number of large earthquakes have decreased. However, in December, 10 earthquakes with seismic intensity 1 or greater were recorded, with the largest being an M3.4 event on December 29. These seismic events occurred within the continental plate.
GNSS observations recorded horizontal deformations on Takarajima, Kodakarajima, and Akusekijima Islands during the recent surge in seismic activity; however, these have since decreased.
– Since July, there has been a notable increase in seismic activity in the ocean near Tokara Islands (near Suwanosejima Island). In December, 10 earthquakes with seismic intensity 1 or greater were recorded (1 event with seismic intensity 3, and 2 events with seismic intensity 2). The largest event in December was an M3.5 event on December 21.
– Although the number of earthquakes has decreased compared to immediately after the M5.8 quake on November 25, 2025, in the Aso region, Kumamoto Prefecture, seismic activity continues, with 14 events with maximum seismic intensity 1 or greater recorded in December (2 events with seismic intensity 3, and 5 events with seismic intensity 2). The largest was an M3.9 earthquake that occurred on December 29.
– "There has been observed no unusual change which indicates
that the possibility of occurrence of a great earthquake along the Nankai
Trough has relatively risen compared to the normal time.":
(This evaluation is in agreement with the views presented at the regular
meeting of the Nankai Trough Earthquake Assessment Committee on January
9 (reference below).)
(Reference)
Recent Crustal Activity Around the Nankai Trough (Seismological and Volcanological Department, Japan Meteorological Agency, January 9, 2026)
"In the present, there has been observed no unusual change which indicates that the possibility of occurrence of great earthquakes along the Nankai Trough has relatively risen compared to the normal time. (Excerpted)"
Reference 1
Earthquakes that are described in the "Evaluation of Seismic Activity" (Monthly Report of Seismic Activity in Japan) have the following features.
Reference 2
Information that is described in the "Supplementary Information to the Evaluation" includes: