M5.7 Earthquake 166 km W of Itoman, Japan — September 18, 2022
2022-09-18 08:09:58 UTC (2022-09-18) · approx. 4:09 PM UTC+8 local
On September 18, 2022 at 08:09 UTC, a magnitude 5.7 shallow crustal earthquake struck 166 km W of Itoman, Japan, at a depth of 10.0 km and coordinates 26.2583°, 126.0051°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 112 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 500, placing it among routine seismic activity. The nearest populated place is Tomigusuku (population 55,715).
Physical scale: An earthquake of magnitude 5.7 releases seismic energy equivalent to roughly 5 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 5.2 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Japan, a region characterized by the intersection of four tectonic plates — Pacific, Philippine Sea, Eurasian, and North American — creating multiple subduction zones. The nearest mapped fault system is the Japan Trench. View all earthquakes in Japan.
Learn more: Magnitude scale · Aftershock sequences
Nearest Populated Places
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 1,290,566 |
| MMI 4 | light | 9,025 |
Earthquake Details
126.0051°E
Technical Information
Common Questions
How strong was the magnitude 5.7 earthquake near Itoman, Japan?
The magnitude 5.7 earthquake that struck 166 km W of Itoman, Japan on September 18, 2022 at 08:09 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 26.2583°, 126.0051°, which is 166 km W of Itoman, Japan. The nearest populated place is Tomigusuku (population 55,715). View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.7 earthquakes can continue for days to weeks and gradually diminish over time.
Has Japan had earthquakes this big before?
The largest recorded earthquake in Japan was the M9.1 Tohoku earthquake of March 11, 2011. Today's magnitude 5.7 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000i91n). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, September 18, 2022). M5.7 Earthquake 166 km W of Itoman, Japan — September 18, 2022. Retrieved November 26, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000i91n/