4.9

M4.9 Earthquake 72 km ENE of Mutsu, JapanDecember 6, 2021

2021-12-06 14:33:21 UTC (2021-12-06) · approx. 11:33 PM UTC+9 local

MagnitudeM4.9(mb)
Time14:33 UTC11:33 PM UTC+9
Depth57.4 kmshallow crustal
Coordinates41.421°, 142.060°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 6, 2021 at 14:33 UTC, a magnitude 4.9 shallow crustal earthquake struck 72 km ENE of Mutsu, Japan, at a depth of 57.4 km and coordinates 41.4212°, 142.0596°.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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

Map showing earthquake epicenter at 41.42°, 142.06°

Earthquake Details

Magnitude
4.9 mb
Depth
57.4 km
shallow crustal
Location
41.4212°N
142.0596°E

Technical Information

Event ID
us6000g9h4
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Azimuthal Gap
87.0°
Min Station Distance
0.981°
RMS Residual
0.73 sec
Last Updated
2022-02-12 23:06:15 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Mutsu, Japan?

The magnitude 4.9 earthquake that struck 72 km ENE of Mutsu, Japan on December 6, 2021 at 14:33 UTC had a depth of 57.4 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 41.4212°, 142.0596°, which is 72 km ENE of Mutsu, Japan. View all earthquakes in Japan.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000g9h4). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, December 6, 2021). M4.9 Earthquake 72 km ENE of Mutsu, JapanDecember 6, 2021. Retrieved February 12, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000g9h4/