4.3

M4.3 Earthquake 134 km ENE of Hachinohe, JapanAugust 10, 2021

2021-08-10 23:28:26 UTC (2021-08-10) · approx. 9:28 AM UTC+10 local

MagnitudeM4.3(mb)
Time23:28 UTC9:28 AM UTC+10
Depth43.9 kmshallow crustal
Coordinates40.939°, 142.989°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 10, 2021 at 23:28 UTC, a magnitude 4.3 shallow crustal earthquake struck 134 km ENE of Hachinohe, Japan, at a depth of 43.9 km and coordinates 40.9394°, 142.9894°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 40.94°, 142.99°

Earthquake Details

Magnitude
4.3 mb
Depth
43.9 km
shallow crustal
Location
40.9394°N
142.9894°E

Technical Information

Event ID
us6000f3zy
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Azimuthal Gap
144.0°
Min Station Distance
1.082°
RMS Residual
0.96 sec
Last Updated
2021-10-23 15:46:02 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Hachinohe, Japan?

The magnitude 4.3 earthquake that struck 134 km ENE of Hachinohe, Japan on August 10, 2021 at 23:28 UTC had a depth of 43.9 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000f3zy). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 10, 2021). M4.3 Earthquake 134 km ENE of Hachinohe, JapanAugust 10, 2021. Retrieved October 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f3zy/