2024 Hyūga-nada earthquake
.jpg) Intensities of the map | |
 USGS ShakeMap | |
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| UTC time | 2024-08-08 07:42:55 |
|---|---|
| USGS-ANSS | ComCat |
| Local date | 8 August 2024 |
| Local time | 16:42:55 JST |
| Duration | ~20 seconds[1] |
| Magnitude | 7.1 MJMA 7.1 Mw |
| Depth | 25 km (16 mi) (USGS) 30 km (19 mi) (JMA) |
| Epicenter | 31°43′08″N 131°31′37″E / 31.719°N 131.527°E |
| Type | Reverse |
| Areas affected | Kyushu, Japan |
| Max. intensity | JMA 6− (MMI VII) |
| Tsunami | 50 cm (1.6 ft) |
| Landslides | Yes |
| Aftershocks | 5.3 MJMA |
| Casualties | 16 injured |
On 8 August 2024, at 16:42:55 JST (07:42 UTC), a Mw 7.1 earthquake struck in the Hyūga Sea off the coast of Miyazaki Prefecture, Kyushu, Japan, 20 km (12 mi) northeast of Nichinan.[2]
Tectonic setting
[edit]The Hyūga Sea is located at the southwestern end of the Nankai Trough, an active subduction zone. The Nankai Trough represents the plate boundary where the Philippine Sea Plate subducts beneath the Eurasian Plate. The area is associated with large earthquakes in 1662 (Mw 7.9), 1941 (Mw 8.0), 1961 (Mw 7.5),[3] 1968 (Mw 7.5) and two in 1996 (Mw 6.6[4] and 6.7[5]). The Hyūga Sea is interpreted as a transition zone between the highly coupled Nankai Trough in the northeast and weakly coupled Ryukyu Trench further southwest.[6] The 1968 and 1996 earthquakes were subduction zone events occurring on the plate boundary. The 2016 Kumamoto earthquakes were about 140 km (87 mi) northwest of the 2024 Hyūga-nada earthquake and were caused by a similar subduction zone.[2] About 2 km (1.2 mi) beneath the seafloor, low-frequency earthquakes, occur near the shallow subduction interface. Beneath the east coast of Kyushu, on the deeper part of the subduction zone, slow slip events were detected between 1996 and 2017.[7]
Earthquake
[edit]The United States Geological Survey reported a magnitude (Mww ) of 7.1, at a depth of 25 km (16 mi) and a maximum Modified Mercalli intensity of VII (Very Strong).[2] At least ten aftershocks were recorded following the event, with the strongest measuring Mw 5.3.[8]
The USGS initially reported two events, measuring magnitudes 7.1 and 6.9 respectively. This was later fixed.[9]
| Intensity | Prefecture | Locations |
|---|---|---|
| 6− | Miyazaki | Nichinan |
| 5+ | Miyazaki | Miyazaki, Kushima, Miyakonojō |
| Kagoshima | Ōsaki | |
| 5− | Miyazaki | Mimata, Kunitomi, Shintomi, Takanabe, Takaharu, Kobayashi |
| Kagoshima | Soo, Kanoya, Kimotsuki, Higashikushira, Tarumizu, Kirishima, Kagoshima, Aira |
On August 9, 2024 at 7:57pm JST, a 5.3MJMA earthquake struck western Kanagawa Prefecture[11], causing tremors recorded as a 5- on the JMA seismic intensity scale and injuring 3.[12] Many in the public believed this earthquake could be related, but Professor Sakai Shinichi of the University of Tokyo's Earthquake Research Institute stated that the Kanagawa earthquake was not related to the Hyūga-nada earthquake or a possible Nankai megathrust earthquake.[13]
Tsunami
[edit]A tsunami advisory was issued after the earthquake. It covered Kōchi, Ehime, Oita, Miyazaki and Kagoshima Prefectures[14] and predicted waves of up to 3.3 feet.[15] Tsunami waves measuring 50 cm (1.6 ft) were subsequently observed in Miyazaki, while waves measuring 20 cm (0.66 ft) were observed in Kōchi.[14] The advisories were lifted at 22:00 JST.[16]
Impact
[edit]The earthquake injured at least 16 people, two of them in a serious condition,[17] destroyed two houses and damaged 53 others across Kyushu.[18][19] Five people were injured in Miyazaki Prefecture; two each in Nichinan and Miyazaki and another in Miyakonojō. In Nichinan, the Obi Castle Town sustained damage. A section of National Route 220 was closed due to rockfalls. A house partially collapsed in Miyazaki, and ten buildings as well as the Miyazaki Airport received minor damage. Two flights each of All Nippon Airways and Solaseed Air were canceled, and some flights of Japan Airlines from the airport were delayed. Water pipe leaks occurred in Kushima. In Kagoshima Prefecture, two people were injured, several walls and a two-story house collapsed, and roads were raised in Ōsaki. A landslide was reported in Shibushi. Two people were injured in Kumamoto Prefecture.[20][21][22][23]
Shinkansen services along the Kyushu and Nishi Kyushu lines were suspended, along with a ferry service from Kobe to Miyazaki. No abnormalities were detected at the Ikata and Sendai nuclear power plants located near the epicenter.[14]
Aftermath
[edit]Following the earthquake, the Japan Meteorological Agency (JMA) issued a 'Nankai Trough Earthquake Extra Information' advisory[24] that the probability of a megathrust earthquake along the Nankai Trough was now "relatively higher" in what was the first advisory of its kind but clarified that it was not imminent.[9][25] While the JMA did state that no abnormal changes to crustal strain were observed, they still maintained the advisory through at least August 10.[26] The JMA did call for those living in areas expected to be impacted by a Nankai megathrust earthquake to follow disaster prevention measures provided by the government,[27] and advised households with children, elderly, or physically disabled individuals to consider voluntarily evacuating.[28] The Japanese government designated 707 municipalities in 29 prefectures, including Tokyo, as areas at risk of being affected by a strong tremor with a intensity of lower 6 or higher and a tsunami with a height of more than three meters.[29]
In response, the Central Japan Railway Company ordered trains at the Tokaido Shinkansen line to run at a slower pace for a week,[14] while Prime Minister Fumio Kishida cancelled a scheduled trip to Central Asia on 9 August[30] as part of government preparations for its possible occurrence.[31] Supermarkets issued a limit of 12 two-liter plastic bottles of drinking water to be sold per family to discourage stockpiling, while demand for drinking water, emergency toilets and preserved foods significantly increased in online shopping websites.[32]
Several hotel booking cancellations were reported in prefectures of Kyushu affected by the earthquake due to the advisory, with at least 150 cancellations recorded in Miyazaki alone.[33]
See also
[edit]
- 1662 Hyūga-nada earthquake
- 1941 Hyūga-nada earthquake
- 1968 Hyūga-nada earthquake
- Nankai megathrust earthquakes
- List of earthquakes in 2024
- List of earthquakes in Japan
References
[edit]- ^ "M 7.1 - 2024 Hyuganada Sea, Japan Earthquake Finite Fault". United States Geological Survey. Retrieved 10 August 2024.
- ^ a b c ANSS. "M 7.1 - 20 km NE of Nichinan, Japan 2024". Comprehensive Catalog. U.S. Geological Survey.
- ^ "M 7.5 - 18 km NNE of Nichinan, Japan". United States Geological Survey. Retrieved 9 August 2024.
- ^ "M 6.6 - 20 km SSE of Nishinoomote, Japan". United States Geological Survey. Retrieved 10 August 2024.
- ^ "M 6.7 - 17 km SW of Miyazaki, Japan". United States Geological Survey. Retrieved 10 August 2024.
- ^ Asano, Youichi; Obara, Kazushige; Matsuzawa, Takanori; Hirose, Hitoshi; Ito, Yoshihiro (2015). "Possible shallow slow slip events in Hyuga-nada, Nankai subduction zone, inferred from the migration of very low frequency earthquakes". Geophysical Research Letters. 42 (12): 331–338. Bibcode:2015GeoRL..42..331A. doi:10.1002/2014GL062165.
- ^ Ioki, Kei; Yamashita, Yusuke; Kase, Yoshihiro (2023). "Effects of the Tsunami Generated by the 1662 Hyuga-Nada Earthquake off Miyazaki Prefecture, Japan". Pure and Applied Geophysics. 180 (6): 1897–1907. Bibcode:2023PApGe.180.1897I. doi:10.1007/s00024-022-03198-3. hdl:2433/284057.
- ^ "Japan Meteorological Agency maintains mega-quake advisory for Nankai Trough". NHK. 9 August 2024. Retrieved 9 August 2024.
- ^ a b Osaki, Tomohiro (8 August 2024). "7.1-magnitude Earthquake Hits Off Japan". Barron's. Retrieved 8 August 2024.
- ^ "Earthquake information". Japan Meteorological Agency. 8 August 2024. Retrieved 8 August 2024.
- ^ "Earthquake information : Detail information". www.data.jma.go.jp. Japan Meteorological Agency. Retrieved 10 August 2024.
- ^ "神奈川県震度5弱 1週間程度は同程度の揺れの地震に注意 | NHK". NHKニュース. 10 August 2024.
- ^ "M5.3 quake hits eastern Japan | NHK WORLD-JAPAN News". NHK WORLD. NHK. 9 August 2024. Retrieved 10 August 2024.
- ^ a b c d "M7.1 quake hits southwestern Japan, megaquake fear grows". Kyodo News. 8 August 2024. Retrieved 8 August 2024.
- ^ "Strong earthquake with 7.1 magnitude hits off southern Japan, prompts tsunami advisory". CBS News. 8 August 2024. Retrieved 8 August 2024.
- ^ "Megaquake advisory issued, tsunami advisories lifted". NHK. 8 August 2024. Retrieved 8 August 2024.
- ^ "Kyushu escapes major damage from magnitude 7.1 earthquake". Japan Times. 9 August 2024. Retrieved 9 August 2024.
- ^ 震度６弱地震で負傷者１２人と防災相 [12 Injured in Magnitude 6 Quake, says Disaster Management Minister]. Ehime Shimbun (in Japanese). 8 August 2024. Retrieved 8 August 2024.
- ^ 宮崎県内の住宅被害は少なくとも53棟 自宅にひび割れがある場合は要注意 巨大地震への備えを [At least 53 houses in Miyazaki Prefecture have been damaged. If there are cracks in your home, be careful. Prepare for a huge earthquake]. umk.go.jp (in Japanese). 8 August 2024. Retrieved 9 August 2024.
- ^ 【被害】宮崎 日南市で2人けが 各地で住宅被害も [Damage: Two people were injured in Nichinan City, Miyazaki, Japan, and damage to houses in various areas.] (in Japanese). NHK. 8 August 2024. Retrieved 8 August 2024.
- ^ 最大震度6弱を観測 宮崎県内の地震被害まとめ（午後６時半時点） [Summary of earthquake damage in Miyazaki Prefecture (as of 6:30 p.m.), with a maximum intensity of 6] (in Japanese). TBS. 8 August 2024. Retrieved 8 August 2024.
- ^ Yamaguchi, Mari (8 August 2024). "A powerful quake hits off Japan's coast, causing minor injuries but prompting new concerns". Associated Press. Retrieved 9 August 2024.
- ^ "Japan issues first 'megaquake' warning after 7.1-magnitude temblor". NBC News. 9 August 2024. Retrieved 9 August 2024.
- ^ 気象庁｜南海トラフ地震に関連する情報 [Information related to the Nankai Trough earthquake]. Japan Meteorological Agency. Retrieved 9 August 2024.
- ^ "Japan sees higher-than-usual risk of megaquake off Pacific Coast". Kyodo News. 8 August 2024. Retrieved 8 August 2024.
- ^ "Japan Meteorological Agency maintains mega-quake advisory for Nankai Trough | NHK WORLD-JAPAN News". NHK WORLD. NHK. 9 August 2024. Retrieved 10 August 2024.
- ^ "Megaquake advisory issued, tsunami advisories lifted". NHK. 8 August 2024. Retrieved 9 August 2024.
- ^ "Japan Meteorological Agency maintains mega-quake advisory for Nankai Trough | NHK WORLD-JAPAN News". NHK WORLD. NHK. 9 August 2024. Retrieved 10 August 2024.
- ^ "What do we need to know about a possible mega-quake?". NHK. 9 August 2024. Retrieved 9 August 2024.
- ^ "Japan PM scraps overseas trip after 'megaquake' advisory". France 24. AFP. 9 August 2024. Retrieved 9 August 2024.
- ^ "Japan PM scraps Central Asia trip after 'megaquake' warning". Al Jazeera. 9 August 2024. Retrieved 9 August 2024.
- ^ "Japan urges public not to hoard disaster kits amid megaquake fear". Kyodo News. 9 August 2024. Retrieved 9 August 2024.
- ^ "Japan braces for potential massive quake after M7.1 temblor". Kyodo News. 9 August 2024. Retrieved 9 August 2024.