4.9

M4.9 Earthquake 10 km W of Honmachi, JapanAugust 5, 2026

2026-08-05 22:59:25 UTC (1 hour ago) · approx. 7:59 AM UTC+9 local

Felt by 6 people across nearby locations. Aftershock of the M5.0 mainshock.

MagnitudeM4.9(mww)
Time22:59 UTC7:59 AM UTC+9
Depth10.0 kmshallow crustal
Coordinates32.491°, 130.485°
Felt by6DYFI responses
Status✓ Reviewed by USGS

On August 5, 2026 at 22:59 UTC, a magnitude 4.9 shallow crustal earthquake struck 10 km W of Honmachi, Japan, at a depth of 10.0 km and coordinates 32.4910°, 130.4850°. This earthquake was detected by 50 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 372, placing it among routine seismic activity.

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.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.0 mainshock that occurred 6 days ago 2 km WNW of Uto, Japan. Since the mainshock, the USGS has recorded 6 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

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 32.49°, 130.49°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 6 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.9 earthquake near 10 km W of Honmachi, Japan

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.9 mww
Depth
10.0 km
shallow crustal
Location
32.4910°N
130.4850°E
Felt Reports
6
DYFI responses
Community Intensity
3.8
CDI from reports

Technical Information

Event ID
us6000tig8
Event Type
earthquake
Status
✓ Reviewed
Significance
372
Stations Used
50
Azimuthal Gap
84.0°
Min Station Distance
0.979°
RMS Residual
1.30 sec
Last Updated
2026-08-05 23:38:26 UTC

Common Questions

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

The magnitude 4.9 earthquake that struck 10 km W of Honmachi, Japan on August 5, 2026 at 22:59 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 32.4910°, 130.4850°, which is 10 km W of Honmachi, 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.

Is this the same earthquake as the M5.0 one earlier?

No. This magnitude 4.9 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 2 km WNW of Uto, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

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: us6000tig8). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 5, 2026). M4.9 Earthquake 10 km W of Honmachi, JapanAugust 5, 2026. Retrieved August 5, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tig8/