M4.6 Earthquake 38 km ESE of Kitaibaraki, Japan — September 27, 2021
2021-09-27 11:26:38 UTC (2021-09-27) · approx. 8:26 PM UTC+9 local
Felt by 15 people across nearby locations.
On September 27, 2021 at 11:26 UTC, a magnitude 4.6 shallow crustal earthquake struck 38 km ESE of Kitaibaraki, Japan, at a depth of 50.4 km and coordinates 36.7055°, 141.1649°.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — 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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 15 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
141.1649°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.6 earthquake near Kitaibaraki, Japan?
The magnitude 4.6 earthquake that struck 38 km ESE of Kitaibaraki, Japan on September 27, 2021 at 11:26 UTC had a depth of 50.4 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 36.7055°, 141.1649°, which is 38 km ESE of Kitaibaraki, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days 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 4.6 event is significantly smaller than that historical record.
Actions
Location
Authoritative source: USGS event page (event ID: us7000fetw). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 27, 2021). M4.6 Earthquake 38 km ESE of Kitaibaraki, Japan — September 27, 2021. Retrieved December 4, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000fetw/