M7.1 Earthquake 73 km ENE of Namie, Japan — February 13, 2021
2021-02-13 14:07:49 UTC (2021-02-13) · approx. 11:07 PM UTC+9 local
Felt by 673 people across surrounding communities. Maximum shaking intensity MMI 8.1 (violent).
On February 13, 2021 at 14:07 UTC, a magnitude 7.1 shallow crustal earthquake struck 73 km ENE of Namie, Japan, at a depth of 44.0 km and coordinates 37.7265°, 141.7751°. The earthquake was reported felt by 673 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 8.1 (violent). The USGS PAGER system issued a orange alert level for this event, indicating regional impact possible. The nearest populated place is Iwanuma (population 42,411).
Physical scale: An earthquake of magnitude 7.1 releases seismic energy equivalent to roughly 674 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 48 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
What the Shaking Felt Like
At MMI 8.1 (violent), people in the most strongly affected areas would have experienced: Severe shaking causing considerable damage. Buildings may shift off foundations. Walls crack and may partially collapse. Heavy furniture overturned.
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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 673 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
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 | 27,832,478 |
| MMI 4 | light | 36,653,484 |
| MMI 5 | moderate | 15,387,663 |
| MMI 6 | strong | 1,861,600 |
| MMI 7 | very strong | 2,308,033 |
| MMI 8 | severe | 105,199 |
Earthquake Details
141.7751°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 7.1 earthquake near Namie, Japan?
The magnitude 7.1 earthquake that struck 73 km ENE of Namie, Japan on February 13, 2021 at 14:07 UTC had a depth of 44.0 km. It was felt by 673 people with maximum shaking intensity of MMI 8.1 (violent). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at 37.7265°, 141.7751°, which is 73 km ENE of Namie, Japan. The nearest populated place is Iwanuma (population 42,411). View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 7.1 earthquakes can continue for months to years 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 7.1 event is significantly smaller than that historical record.
Actions
Location
Authoritative source: USGS event page (event ID: us6000dher). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, February 13, 2021). M7.1 Earthquake 73 km ENE of Namie, Japan — February 13, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000dher/