# M5.5 Earthquake: 75 km S of Yonakuni, Japan Updated 09:06 UTC, 29 Oct 2026. Canonical: https://monitorworld.app/earthquake/2026-09-30-m5-5-yonakuni-japan A **magnitude 5.5** earthquake struck 75 km S of Yonakuni, Japan at 05:00 UTC on 30 Sep 2026, at a depth of 10 km, reported by USGS. USGS PAGER issued a green alert: little or no damage and a low chance of deaths. USGS did not set a tsunami flag for this quake. So far 2 aftershocks of M2.5+ have been recorded within 50 km, the largest a M4.5. ## Key numbers - Magnitude (USGS): **M5.5** (mww) - Depth: **10 km** (shallow) - USGS PAGER impact alert: **GREEN** (estimated impact) - Aftershocks M2.5+ so far: **2** (within 50 km) ## Nearest places - [76 KM] Yonakuni, Okinawa, Japan (76 km from the epicentre, quake was S of here, population 1,684) - [134 KM] Hualien City, Taiwan, Taiwan (134 km from the epicentre, quake was E of here, population 350,468) - [142 KM] Ishigaki, Okinawa, Japan (142 km from the epicentre, quake was WSW of here, population 44,802) - [158 KM] Yilan, Taiwan, Taiwan (158 km from the epicentre, quake was SE of here, population 94,188) - [226 KM] Zhongxing New Village, Taiwan, Taiwan (226 km from the epicentre, quake was E of here, population 25,549) - [190 KM] Keelung, Taiwan (190 km from the epicentre, quake was SE of here, population 362,000) - [190 KM] Xizhi, Taiwan (190 km from the epicentre, quake was SE of here, population 205,000) - [195 KM] Neihu, Taiwan (195 km from the epicentre, quake was SE of here, population 275,000) - [197 KM] Taipei, Taiwan (197 km from the epicentre, quake was SE of here, population 7,872,000) ## Strongest aftershocks so far - [LOW] [M4.5 · 63 km S of Yonakuni, Japan](https://earthquake.usgs.gov/earthquakes/eventpage/us6000u0sh) (2026-09-30 10:37 UTC, 33 km deep, USGS) - [LOW] [M4.0 · 81 km S of Yonakuni, Japan](https://earthquake.usgs.gov/earthquakes/eventpage/us6000tyjm) (2026-09-30 12:02 UTC, 10 km deep, USGS) ## Key context ### Tectonic setting **Taiwan collision zone.** Taiwan is being built by the collision of the Philippine Sea Plate with the edge of the Eurasian Plate at about 8 cm per year. The east coast near Hualien is the most active part; the M7.7 Chi-Chi quake of 1999 and the M7.4 Hualien quake of 3 April 2024 were the largest recent events. The USGS moment tensor shows strike-slip faulting: the two sides of the fault slid sideways past each other. At 10 km it was a very shallow quake: shallow quakes shake the ground above them hardest, so local damage depends on how close towns are. ### Shaking and impact USGS PAGER estimates the impact from the shaking and the number of people exposed. For this quake it issued a green alert: little or no damage and a low chance of deaths (fatality alert: green, economic loss alert: green). PAGER is an early estimate and can change as reports come in. The USGS ShakeMap estimates the strongest shaking at intensity IV on the Modified Mercalli scale (light). 11 people sent a "Did You Feel It?" report to USGS, with the strongest reported intensity IV (light). ### Aftershocks This page counts quakes of M2.5 or more within 50 km after the main shock, from the USGS catalog (last checked 09:06 UTC, 29 Oct 2026): 2 aftershocks so far. Aftershocks are normal after a quake of this size. They usually become less frequent over days and weeks, but a strong aftershock can still happen, and in a few sequences a later quake is larger. No one can predict their exact time or size; follow the official agency for your area. ### Earthquake history within 250 km Since 1976, USGS lists 912 quakes of M5 or more within 250 km of this epicentre, about 18 a year. Since 1900 the same circle had 587 quakes of M5.5 or larger. Largest earlier quakes within 250 km, USGS catalog since 1900 (M6+). | Magnitude | Place (USGS) | Date | Depth | | --- | --- | --- | --- | | M8.2 | 1920 Hualien, Taiwan Earthquake | 1920-06-05 | 20 km | | M7.8 | Taiwan | 1951-11-24 | 30 km | | M7.7 | 21 km S of Puli, Taiwan | 1999-09-20 | 33 km | | M7.7 | 50 km SSE of Yilan, Taiwan | 1922-09-01 | 20 km | | M7.5 | 38 km SW of Yonakuni, Japan | 1966-03-12 | 25 km | | M7.5 | 58 km SSW of Hualien City, Taiwan | 1951-10-21 | 25 km | | M7.4 | 15 km S of Hualien City, Taiwan | 2024-04-02 | 40 km | | M7.4 | 85 km ENE of Hengchun, Taiwan | 1978-07-23 | 17 km | ### Official information - [Japan Meteorological Agency (JMA)](https://www.jma.go.jp/jma/indexe.html) - [EMSC (European-Mediterranean Seismological Centre)](https://www.emsc-csem.org/) - [USGS event page for this quake](https://earthquake.usgs.gov/earthquakes/eventpage/us6000tyhk) (ShakeMap, PAGER, felt reports) - [tsunami.gov](https://www.tsunami.gov/) for US tsunami bulletins ### Data status USGS review status: reviewed. Magnitude type: mww. USGS last updated this event on 20 Oct 2026 at 07:06 UTC. Magnitude, depth and location can still be revised; this page keeps the same address if they change. ## FAQ ### How strong was the earthquake near Yonakuni, Japan? USGS measured it at magnitude 5.5 (mww), 10 km deep. The strongest estimated shaking was intensity IV (light). Quakes of M5 to 5.9 are classed as moderate. ### Was there a tsunami? USGS did not set a tsunami flag for this quake. If you are on a coast and feel strong or long shaking, move to high ground anyway, and follow local officials. ### Was the earthquake felt? Yes. 11 people reported it to USGS "Did You Feel It?", with reports up to intensity IV. ### Will there be more aftershocks? Aftershocks are likely to continue for days to weeks, becoming less frequent over time. So far 2 aftershocks of M2.5+ have been listed. Most sequences do not produce a larger quake, but some do. No one can predict the time or size of the next one; follow Japan Meteorological Agency (JMA). ### What should I do after a strong earthquake? Expect aftershocks: Drop, Cover and Hold On when shaking starts again. Check for injuries and damage, stay out of damaged buildings, and use text messages instead of calls so emergency lines stay free. On a coast, move to high ground after strong shaking. Follow your local officials. ## Get the app MonitorWorld is free on iPhone and Android, rated 4.7 from 52 ratings on the US App Store. - App Store: https://apps.apple.com/app/id6760610225 - Google Play: https://play.google.com/store/apps/details?id=app.monitorworld ## Sources - [USGS event page](https://earthquake.usgs.gov/earthquakes/eventpage/us6000tyhk): magnitude, location, ShakeMap, PAGER and Did You Feel It? data for this event. Public domain. Credit: U.S. Geological Survey. - [USGS ComCat (FDSN event web service)](https://earthquake.usgs.gov/fdsnws/event/1/): the USGS earthquake catalog, used for the 30-year counts, history and aftershocks. Public domain. Credit: U.S. Geological Survey. - [USGS Geoserve](https://earthquake.usgs.gov/ws/geoserve/): nearest places to the epicentre. - [GeoNames](https://www.geonames.org/): large-city coordinates, CC BY 4.0. ## Related - [Taiwan earthquakes](https://monitorworld.app/live/earthquakes/taiwan): Live map and the 30-year normal in and around Taiwan. - [M6.5 Bonin Islands, Japan region](https://monitorworld.app/earthquake/2026-10-25-m6-5-bonin-islands-japan-region): 25 Oct 2026, 1,731 km from this quake. - [M5.8 Barcelona, Philippines](https://monitorworld.app/earthquake/2026-10-29-m5-8-barcelona-philippines): 29 Oct 2026, 1,782 km from this quake. - [Earthquakes today](https://monitorworld.app/live/earthquakes-today): Every M2.5+ quake of the past 24 hours. - [Earthquakes by region](https://monitorworld.app/live/earthquakes): All regions and every M5.5+ quake page. - [Tsunami warning today](https://monitorworld.app/live/tsunami-warning): Latest US tsunami bulletins. - [Earthquake near me](https://monitorworld.app/live/earthquake-near-me): Sort recent quakes by distance from you.