The Japan Meteorological Agency (JMA) Seismic Intensity Scale is a seismic intensity scale used in Japan to categorize the intensity of local ground shaking caused by earthquakes.
The Chūetsu offshore earthquake) was a powerful magnitude 6.6 earthquake that occurred 10:13 local time on July 16, 2007, in the northwest Niigata region of Japan. The earthquake, which occurred at a previously unknown offshore fault shook Niigata and neighbouring prefectures. The city of Kashiwazaki and the villages of Iizuna and Kariwa registered the highest seismic intensity of a strong 6 on Japan's shindo scale, and the quake was felt as far away as Tokyo. Eleven deaths and at least 1,000 injuries were reported, and 342 buildings were completely destroyed, mostly older wooden structures. Prime Minister Shinzō Abe broke off from his election campaign to visit Kashiwazaki and promised to "make every effort towards rescue and also to restore services such as gas and electricity".
In seismology, a supershear earthquake is an earthquake in which the propagation of the rupture along the fault surface occurs at speeds in excess of the seismic shear wave (S-wave) velocity. This causes an effect analogous to a sonic boom.
On June 14, the 2008 Iwate earthquake struck the Tōhoku region of northeastern Honshū in Japan. Japan Meteorological Agency (JMA) officially named this earthquake the Iwate–Miyagi Nairiku earthquake in 2008. This earthquake occurred in the south of the inland of Iwate Prefecture at 8:43 JST on June 14. The JMA magnitude was estimated at MJMA 7.2, and the moment magnitude by USGS was at 6.9. The epicenter was located at 39°01.7′N140°52.8′E, about 85 kilometres (55 mi) north of Sendai and about 385 kilometres (240 mi) north-northeast of Tokyo.
In Japan, the Earthquake Early Warning (EEW) is a warning issued when an earthquake is detected by multiple seismometers. These warnings are primarily issued by the Japan Meteorological Agency (JMA), with guidance on how to react to them.
The Tōkai earthquakes are major earthquakes that have occurred regularly with a return period of 100 to 150 years in the Tōkai region of Japan. The Tōkai segment has been struck by earthquakes in 1498, 1605, 1707, and 1854. Given the historic regularity of these earthquakes, Kiyoo Mogi in 1969 pointed out that another great shallow earthquake was possible in the "near future".
The 1984 Nagano earthquake hit the western part of Nagano Prefecture, Japan on September 14, 1984, at 08:48 local time. Registering a magnitude of 6.3, the earthquake destroyed Otaki, and triggered major landslides. The earthquake left at least 29 people dead or missing, making it the deadliest earthquake in 1984.
The 1993 southwest-off Hokkaido earthquake or Okushiri earthquake occurred at 13:17:12 UTC on 12 July 1993 in the Sea of Japan near the island of Hokkaido. It had a magnitude of 7.7 on the moment magnitude scale and a maximum felt intensity of VIII (Severe) on the Mercalli intensity scale. It triggered a major tsunami that caused deaths on Hokkaidō and in southeastern Russia, with a total of 230 fatalities recorded. The island of Okushiri was hardest hit, with 165 casualties from the earthquake, the tsunami and a large landslide.
The 1771 Great Yaeyama Tsunami was caused by the Yaeyama Great Earthquake at about 8 A.M. on April 24, 1771, south-southeast of Ishigaki Island, part of the former Ryūkyū Kingdom and now part of present-day Okinawa, Japan. According to records, 8,439 people were killed on Ishigaki Island and 2,548 on Miyako Island.
A potent magnitude 6.6 Mw intraplate aftershock occurred at 17:16 JST (08:16 UTC) on 11 April, in the Hamadōri region of Fukushima, Japan. With a shallow focus of 13 km (8.1 mi), the earthquake was centred inland about 36 km (22 mi) west of Iwaki, causing widespread strong to locally severe shaking. It was one of many aftershocks to follow the 11 March Tōhoku earthquake, and the strongest to have its epicentre located inland.
The 2012 Sanriku earthquake occurred near the city of Kamaishi, Japan, on December 7 at 17:18 JST. The magnitude 7.3 shock generated a small tsunami, with waves up to 1 m high, that hit Ishinomaki in Miyagi Prefecture. It occurred at a depth of 36 km within the Pacific Plate and was the result of reverse faulting, about 20 kilometres (12 mi) east of the Japan Trench.
The Lushan earthquake or Ya'an earthquake occurred at 08:02 Beijing Time on April 20, 2013. The epicenter was located in Lushan County, Ya'an, Sichuan, about 116 km (72 mi) from Chengdu along the Longmenshan Fault in the same province heavily impacted by the 2008 Sichuan earthquake. The magnitude of the earthquake was placed at Ms 7.0 by China Earthquake Data Center, Ms 7.0 by Russian Academy of Sciences, Mw 7.0 by Geoscience Australia, Mw 6.6 by the United States Geological Survey (USGS), Mw 6.6 by the European Alert System (EMSC) and Mj 6.9 by the Japan Meteorological Agency (JMA). 1,815 aftershocks have been recorded as of 00:00 (UTC+8h) April 22.
On December 7, 2015, an earthquake measuring 7.2 on the moment magnitude scale struck Tajikistan 105 km (65 mi) west of Murghab at 07:50 UTC at a depth of 26.0 km (16.2 mi). The earthquake was also felt in neighboring Xinjiang in China, India, Afghanistan, Pakistan and Kyrgyzstan.
The 2019 Yamagata earthquake was an earthquake of magnitude 6.4 which struck primarily the Hokuriku region in Japan on 18 June 2019 at 22:22 JST. The epicenter was close to the city of Tsuruoka, Yamagata. A tsunami warning was also issued.
The Nemuro-Oki earthquake in scientific literature, occurred on June 17 at 12:55 local time. It struck with an epicenter just off the Nemuro Peninsula in northern Hokkaidō, Japan. It measured 7.8–7.9 on the moment magnitude scale (Mw ), 8.1 on the tsunami magnitude scale (Mt ) and 7.4 on the Japan Meteorological Agency magnitude scale (MJMA ).
The 2011 Nagano earthquake was an earthquake that occurred near the border between Niigata and Nagano prefectures at 3:59 JST on March 12, 2011. The depth of the hypocenter was 8 km and magnitude of the earthquake was 6.7.
The 1982 Urakawa earthquake was a 6.9 earthquake that struck off the coast of Urakawa, Japan on 11:32 (JST), March 21, 1982. The epicenter was 42.1°N 142.6°E. The earthquake was the largest earthquake in the history of the region. The earthquake caused 167 injuries and damage in Tomakomai and Sapporo.
The Shōnai offshore earthquake occurred at around 14:00 on December 7, 1833. It struck with an epicenter in the Sea of Japan, off the coast of Yamagata Prefecture, Japan. A tsunami was triggered by the estimated MJMA 7.5–7.7 earthquake. One hundred and fifty people were killed and there was severe damage in the prefecture.
The 1940 Shakotan earthquake occurred on August 2 at 00:08:22 JST with a moment magnitude (Mw ) of 7.5 and maximum JMA seismic intensity of Shindo 4. The shock had an epicenter off the coast of Hokkaido, Japan. Damage from the shock was comparatively light, but the accomanying tsunami was destructive. The tsunami caused 10 deaths and 24 injuries on Hokkaido, and destroyed homes and boats across the Sea of Japan. The highest tsunami waves were recorded at the coast of Russia while along the coast of Hokkaido, waves were about 2 m.
On 5 May 2023, a magnitude 6.3 earthquake struck off the coast of Ishikawa Prefecture, Japan. It was located 49 kilometres northeast of Anamizu, Hōsu District, with the town of Suzu closest to the epicenter.
