M4.2 Earthquake 41 km SE of Ichinohe, Japan — October 27, 2021
2021-10-27 20:53:56 UTC (2021-10-27) · approx. 5:53 AM UTC+9 local
On October 27, 2021 at 20:53 UTC, a magnitude 4.2 intermediate depth earthquake struck 41 km SE of Ichinohe, Japan, at a depth of 72.4 km and coordinates 39.9387°, 141.6147°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response 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
141.6147°E
Technical Information
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Common Questions
How strong was the magnitude 4.2 earthquake near Ichinohe, Japan?
The magnitude 4.2 earthquake that struck 41 km SE of Ichinohe, Japan on October 27, 2021 at 20:53 UTC had a depth of 72.4 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000fp9h). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 27, 2021). M4.2 Earthquake 41 km SE of Ichinohe, Japan — October 27, 2021. Retrieved January 8, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000fp9h/