2025 Aomori earthquake

2025 Aomori earthquake
USGS ShakeMap
UTC time2025-12-08 14:15
USGS-ANSSComCat
Local date8 December 2025 (2025-12-08)
Local time23:15 JST (UTC+9)
Duration30 seconds
MagnitudeMJMA 7.5
Mw 7.6
Depth45.5 km (28 mi)
Epicenter40°57′36″N 142°11′06″E / 40.960°N 142.185°E / 40.960; 142.185
TypeThrust
Areas affectedSanriku and Hokkaido, Japan
Max. intensityJMA 6+ (MMI VIII)
Peak acceleration0.472 g
Peak velocity44.82 cm (17.65 in)/s
Tsunami70 cm (28 in)
Aftershocks31+ ≥Mw 4.0[1]
Mww 6.7 on 12 December 2025 (strongest)
Casualties47 injuries

On 8 December 2025, at 23:15 JST (14:15 UTC), a Mw 7.6 earthquake struck in the Pacific Ocean off the coast of Aomori Prefecture, Sanriku, Japan.[2] It generated tsunamis that reached heights of up to 70 cm (28 in) along the coast of northern Japan. The earthquake resulted in injuries to 47 people, damaged nearly 1,400 buildings in Aomori and Hokkaido, and triggered the Off the Coast of Hokkaido and Sanriku Subsequent Earthquake Advisory due to fears of a more powerful earthquake along the Sanriku and Hokkaido coasts.

Tectonic setting

The northern part of Honshu and Hokkaido lie above the convergent plate boundary, where the Pacific plate is subducting beneath the Okhotsk microplate. The convergence rate across this boundary lies in the range of 7.9–9.2 cm (3.1–3.6 in) per year.[3] The plate interface in the area of the earthquake epicenter shows an abrupt increase in dip from about 5° to about 15°, 80 km (50 mi) landward of the Japan Trench.[4] This part of the plate boundary has been the location of many powerful historical earthquakes, dating back to the 869 Sanriku earthquake and most recently of the devastating 2011 Tōhoku earthquake. Most of these events relate to rupture along the plate interface, but some, such as the 1933 Sanriku earthquake,[5] involved deformation within the subducting plate. According to the studies of past great earthquakes, a weak seismic coupling is suggested in the offshore Sanriku region.[6] From the distribution of past seismicity, the width of coupling at 40°N was assumed to be about 150 km (93 mi).[7]

Earthquake

The earthquake occurred on 8 December 2025 at 23:15 local time (14:15 UTC) with an epicenter off the coast of Aomori Prefecture. The United States Geological Survey said it measured the earthquake as Mw 7.6 and was caused by thrust faulting at a depth of 53.1 km (33.0 mi).[2] The Japan Meteorological Agency placed the earthquake's magnitude at Mw 7.5[8] and measured a maximum intensity of upper 6 on the Shindo scale in Hachinohe.[9] Shaking was felt as far as Tokyo[10] and lasted for more than 30 seconds.[11] A USGS seismic installation at Noheji recorded 0.3326 g in ground acceleration (pga) and 44.82 cm/s (17.65 in/s) in ground velocity (pgv); the station data corresponded to a Modified Mercalli intensity (MMI) of VIII (Severe); another installation at Hachinohe recorded a pga of 0.472 g.[12] A 5.5 mb aftershock occurred at 23:33 JST (14:33 UTC),[13] followed by a 5.8 mb aftershock at 03:56 JST (18:56 UTC)[14] and a Mww 6.6 aftershock at 06:52 JST (21:52 UTC).[15] A Mww 6.7 aftershock occurred at 11:44 JST (02:44 UTC) on 12 December.[16]

Locations with a seismic intensity of Shindo 5− and higher[17]
Intensity Prefecture Locations
6+ Aomori Hachinohe
6− Aomori Oirase, Hashikami
5+ Aomori Noheji, Shichinohe, Tōhoku, Gonohe, Nanbu, Mutsu, Higashidōri
Hokkaido Hakodate
Iwate Karumai, Ichinohe
5− Aomori Misawa, Rokunohe, Yokohama, Rokkasho, Sannohe, Goshogawara, Tsugaru, Hiranai, Sotogahama, Tsuruta
Hokkaido Shinshinotsu, Chitose, Nanporo, Tomakomai, Shiraoi, Atsuma, Abira, Mukawa, Niikappu, Shinhidaka, Urakawa, Samani, Urahoro, Taiki
Iwate Morioka, Ninohe, Hachimantai, Takizawa, Kuji
Miyagi Tome

Tsunami

Tsunami warnings for waves of up to 3 m (9.8 ft)[10] were issued along the Pacific coasts of Aomori, Iwate, and Hokkaido Prefectures,[18][19] while a tsunami advisory was issued in Miyagi and Fukushima Prefectures.[9] More than 90,000 people were ordered to be evacuated.[20] The Pacific Tsunami Warning Center said hazardous waves were possible as far as 1,000 km (620 mi) from the epicenter, affecting the coasts of Japan and Russia.[21] The JMA lifted all tsunami advisories at 06:30 JST on 9 December.[22]

Waves reaching up to 70 cm (28 in) were observed in Kuji,[23] while 50 cm (20 in) waves were observed in Urakawa. Waves reaching 40 cm (16 in) were observed in Mutsu and Hachinohe. In Erimo, wave heights reached 30 cm (12 in), and in Tomakomai, Shiraoi, Kamaishi, Ishinomaki, and Sendai, it was 20 cm (7.9 in).[24]

Following the Mww 6.7 aftershock on 12 December, the JMA issued tsunami advisories for waves of up to 1 m (3 ft 3 in) off the Pacific coast of Hokkaido, Aomori, Iwate and Miyagi prefectures.[25] An evacuation order was issued by authorities in Sendai.[26] Waves measuring 20 cm (7.9 in) were observed in Erimo and Hachinohe, after which the advisory was lifted at 14:05 JST (05:05 UTC).[27]

Impact

At least 47 people were injured including 32 in Aomori, 11 in Hokkaido, and 4 in Iwate.[28] In Aomori, three homes collapsed and 1,377 structures were damaged, including 391 homes, 279 commercial and industrial buildings, 197 welfare facilities, 189 schools, 7 ports, 5 hospitals and 5 prefectural facilities. There were 15 injuries in Hachinohe, 2 each in Mutsu, Tōhoku and Misawa, and 1 each in Oirase, Hashikami, Aomori City, Hiranai, Goshogawara.[29] In Hachinohe, 236 houses[29] and a restaurant were damaged, windows shattered and ground heaves were reported.[30] Liquefaction damage also occurred at the Port of Hachinohe, with Higashidōri, Yokohama and Misawa's ports also suffering damage.[29] Two fires occurred in Aomori City,[31] while one person was injured after his car fell into a hole in Tōhoku.[32] An elderly woman was wounded by a falling cabinet in Oirase, while another woman was injured by falling debris in her home in Goshogawara. Two people were also injured after falling in Tomakomai, Hokkaido.[33] Two homes were damaged in the prefecture.[28]

Services on the Tōhoku Shinkansen between Shin-Aomori Station and Fukushima Station were suspended.[34][35] A shinkansen train carrying 94 passengers was stranded in Aomori.[10] In total, 26 trains were suspended and nine were delayed for up to 71 minutes, affecting around 17,000 people. Sixty passengers were transferred to buses.[36] The release of treated wastewater from the Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean was suspended.[9] Around 480 L (110 imp gal; 130 US gal) of water spilled from a spent fuel cooling area at the Rokkasho Reprocessing Plant. The Nuclear Regulation Authority said the facility's water level remained within the normal range and there was no safety concern.[22]

Power outages were reported in Iwate and Hokkaido.[37] Around 2,700 houses in Aomori Prefecture lost electricity.[38] Several oyster rafts were damaged by tsunami waves. The ceiling of the domestic terminal at New Chitose Airport partially cracked and collapsed, stranding 200 passengers.[22] A hospital in Mutsu was partially flooded after its sprinkler system was damaged, forcing the evacuation of 31 patients. Around 1,360 homes in Aomori and Iwate lost water due to damaged pipes.[39] Classes were suspended at more than 300 schools in Hokkaido, Aomori, Iwate, Miyagi and Fukushima prefectures.[40] At least 450 buildings in Aomori were damaged.[41]

Following the Mww 6.7 aftershock on 12 December, authorities in Hachinohe ordered the evacuation of 48 households near a telecom tower owned by NTT East that was damaged during the mainshock on 8 December, citing the risk of a total collapse.[42] Services on the Tohoku Shinkansen were again suspended due to power outages between Sendai and Aomori stations.[27] A woman was injured due to a fall in Hiranai.[43]

Response

The Japanese government established a task force to respond to the earthquake.[9] Around 620 residents and 270 vehicles sheltered at JSDF facilities in Hachinohe,[39] while 18 JSDF helicopters were mobilized to conduct a damage assessment.[22] Up to 342 evacuation shelters were opened across five prefectures and used by around 9,200 people.[40]

Following the earthquake, the JMA issued the first "Off the Coast of Hokkaido and Sanriku Subsequent Earthquake Advisory", advising of an increased possibility of a stronger earthquake hitting the Hokkaido and Sanriku coasts in the following days.[10] The advisory is issued following a large (7+ Mw) earthquake in the region of the Kuril–Kamchatka and Japan Trenches and analysis determines that the chance of a larger earthquake increases from 0.1% per week to 1% per week.[44] For example, the Mw  9.1 2011 Tōhoku earthquake and tsunami was preceded by a Mw  7.2 foreshock two days prior.[45] The purpose of the advisory is to increase disaster preparedness in the potentially affected areas along Japan's Pacific coasts, however it does not begin evacuation procedures.[46][47] The advisory affected 182 municipalities from Hokkaido to Chiba Prefecture.[22] Its issuance led to an increase in northeastern Japan of purchases of disaster-related items such as bottled water, disaster kits, torches, water storage tanks and support poles.[48] The JMA lifted the advisory on 16 December.[49]

See also

References

  1. ^ "USGS earthquake catalog". United States Geological Survey.
  2. ^ a b ANSS. "M 7.6 – 2025 Aomori Prefecture, Japan Earthquake 2025". Comprehensive Catalog. U.S. Geological Survey.
  3. ^ Nishimura, T.; Miura S.; Tachibana K.; Hashimoto K.; Sato T.; Hori S.; Murakami E.; Kono T.; Nida K.; Mishina M.; Hirasawa T. & Miyazaki S. (2000). "Distribution of seismic coupling on the subducting plate boundary in northeastern Japan inferred from GPS observations". Tectonophysics. 323 (3–4): 217–238. Bibcode:2000Tectp.323..217N. doi:10.1016/S0040-1951(00)00108-6.
  4. ^ Ito, A.; Fujie G.; Tsuru T.; Kodaira S.; Nakanishi A. & Kaneda Y. (2004). "Fault plane geometry in the source region of the 1994 Sanriku-oki earthquake". Earth and Planetary Science Letters. 223 (1–2): 163–175. Bibcode:2004E&PSL.223..163I. doi:10.1016/j.epsl.2004.04.007.
  5. ^ Kanamori, H. (1971). "Seismological evidence for a lithospheric normal faulting – the Sanriku earthquake of 1933" (PDF). Physics of the Earth and Planetary Interiors. 4 (4): 289–300. Bibcode:1971PEPI....4..289K. doi:10.1016/0031-9201(71)90013-6. Archived from the original (PDF) on 19 March 2012. Retrieved 13 July 2011.
  6. ^ Takahashi, N.; Kodaira S.; Tsuru T.; Park J-O.; Kaneda Y.; Suyehiro K.; Kinoshita H.; Abe S.; Nishino M. & Hino R. (2004). "Seismic structure and seismogenesis off Sanriku region, northeastern Japan". Geophysical Journal International. 159 (1): 129–145. Bibcode:2004GeoJI.159..129T. doi:10.1111/j.1365-246X.2004.02350.x.
  7. ^ Kawasaki, I.; Asai Y. & Tamura Y. (2001). "Space–time distribution of interplate moment release including slow earthquakes and the seismo-geodetic coupling in the Sanriku-oki region along the Japan trench" (PDF). Tectonophysics. 330 (3–4): 276–283. Bibcode:2001Tectp.330..267K. doi:10.1016/S0040-1951(00)00245-6. Retrieved 13 July 2011.
  8. ^ "Major Japan quake injures 30, damages roads". France 24. 9 December 2025.
  9. ^ a b c d "Strong earthquake hits northern Japan, tsunami warning issued". NHK. 8 December 2025.
  10. ^ a b c d "M7.6 quake strikes northeastern Japan, tsunami warning issued". Kyodo News. 8 December 2025.
  11. ^ "Evacuation orders issued in Japan after powerful earthquake triggers tsunami warning". CNN. 8 December 2025.
  12. ^ ANSS. "M 7.6 – 2025 Aomori Prefecture, Japan Earthquake – ShakeMap 2025". Comprehensive Catalog. U.S. Geological Survey.
  13. ^ ANSS. "M 5.5 – 96 km ENE of Hachinohe, Japan 2025". Comprehensive Catalog. U.S. Geological Survey.
  14. ^ ANSS. "M 5.8 – 124 km S of Honchō, Japan 2025". Comprehensive Catalog. U.S. Geological Survey.
  15. ^ ANSS. "M 6.6 – 125 km S of Honchō, Japan 2025". Comprehensive Catalog. U.S. Geological Survey.
  16. ^ ANSS. "M 6.7 – 114 km ENE of Hachinohe, Japan 2025". Comprehensive Catalog. U.S. Geological Survey.
  17. ^ "Earthquake information". Japan Meteorological Agency. 8 December 2025. Retrieved 8 December 2025.
  18. ^ "青森県で震度6強の地震...青森、北海道、岩手に津波警報 津波注意報発表の地域一覧...12月8日23時15分発生 | 社会 | 福井のニュース". 福井新聞ONLINE (in Japanese). Retrieved 8 December 2025.
  19. ^ "BULLETIN: M7.6 quake strikes northeastern Japan, tsunami warning issued". Kyodo News. 8 December 2025.
  20. ^ "Dozens injured after magnitude 7.5 quake strikes northern Japan". BBC. Retrieved 9 December 2025.
  21. ^ "Magnitude 7.6 earthquake triggers tsunami on Japan's northern coast". Al Jazeera. Retrieved 8 December 2025.
  22. ^ a b c d e "Japan assesses damage from 7.5 magnitude quake that injured 34". AP News. 9 December 2025.
  23. ^ "BREAKING NEWS: 70-centimeter tsunami observed in Iwate Pref. after M7.6 quake". Kyodo News. Retrieved 8 December 2025.
  24. ^ "JMA Latest Tsunami Information". JMA. Retrieved 8 December 2025.
  25. ^ "Tsunami advisory issued for north, northeast Japan after M6.7 quake". Kyodo News. 12 December 2025.
  26. ^ "Tsunami advisory issued for northern Japan's Pacific coast". NHK. 12 December 2025.
  27. ^ a b "Northeast Japan jolted again days after M7.5 quake, small tsunami observed for now". Kyodo News. 12 December 2025.
  28. ^ a b 青森県東方沖を震源とする地震による被害及び消防機関等の対応状況 (第15報) (PDF) (Report) (in Japanese). Fire and Disaster Management Agency. 12 December 2025.
  29. ^ a b c 令和7年12月8日青森県東方沖地震に係る被害報 (第11報) (Report) (in Japanese). Aomori Prefectural Government. 19 December 2025.
  30. ^ "【速報】震度6強の青森・八戸市 ビルの外壁がはがれ店舗の窓ガラスが割れるなどの被害...周辺で地面の隆起も 飲食店男性が語る". Fuji News Network (in Japanese). 8 December 2025. Retrieved 8 December 2025.
  31. ^ "BREAKING NEWS: 2 fire incidents confirmed in Aomori city after quake". Kyodo News. Retrieved 8 December 2025.
  32. ^ "Magnitude 7.6 quake triggers a tsunami on Japan's northern coast". AP News. 8 December 2025.
  33. ^ "青森や北海道でけが人 5道県で避難指示". Iwate Nippo (in Japanese). 8 December 2025. Retrieved 8 December 2025.
  34. ^ 日本放送協会 (8 December 2025). "【交通影響】震度6強で東北新幹線 福島〜新青森駅運転見合わせ". NHKニュース (in Japanese). Retrieved 8 December 2025.
  35. ^ "BREAKING NEWS: Tohoku Shinkansen services in northeastern Japan halted due to quake". Kyodo News. 8 December 2025.
  36. ^ "Bullet train services in northeastern Japan resume after quake". Kyodo News. 9 December 2025.
  37. ^ "停電情報". Yahoo!天気・災害 (in Japanese). Retrieved 8 December 2025.
  38. ^ "BREAKING NEWS: 2,700 homes in Aomori Pref. experience power outages". Kyodo News. Retrieved 8 December 2025.
  39. ^ a b "Dozens injured in M7.5 quake in Japan, gov't warns of bigger temblor". Kyodo News. 9 December 2025.
  40. ^ a b "Schools reopen in Japan after M7.5 quake amid alert for another temblor". Kyodo News. 10 December 2025.
  41. ^ "【速報】8日の青森の「震度6強」地震　建物被害は400件以上に　青森県内". Yahoo! News Japan. 12 December 2025.
  42. ^ "Damaged tower in quake-hit Japanese city judged safe from collapse for now". Kyodo News. 12 December 2025.
  43. ^ "青森で震度4　一時津波注意報　1人ケガ". Yahoo! News Japan. 13 December 2025.
  44. ^ "北海道・三陸沖後発地震注意情報の解説ページ : 防災情報のページ – 内閣府". Bousai (in Japanese). Retrieved 8 December 2025.
  45. ^ "北海道・三陸沖後発地震注意情報について" (PDF) (in Japanese). 気 象 庁 地 震 火 山 部. 9 December 2025. Retrieved 8 December 2025.
  46. ^ "Megaquakes along the Japan and Chishima Trenches" (PDF). Japan Meteorological Agency.
  47. ^ "北海道・三陸沖後発地震注意情報の解説ページ : 防災情報のページ – 内閣府". Bousai (in Japanese). Retrieved 8 December 2025.
  48. ^ "Tsunami warning lifted after latest earthquake hits Japan's northeast". Al Jazeera. 12 December 2025. Retrieved 12 December 2025.
  49. ^ "Mega quake advisory for northern, eastern Japan ends". NHK. 20 December 2025. Retrieved 15 December 2025.
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.