4.4

M4.4 Earthquake 121 km E of Miyako, JapanApril 29, 2026

2026-04-29 00:43:35 UTC (2 hours ago) · approx. 10:43 AM UTC+10 local

MagnitudeM4.4(mb)
Time00:43 UTC10:43 AM UTC+10
Depth35.0 kmshallow crustal
Coordinates39.726°, 143.350°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 29, 2026 at 00:43 UTC, a magnitude 4.4 shallow crustal earthquake struck 121 km E of Miyako, Japan, at a depth of 35.0 km and coordinates 39.7257°, 143.3502°.

Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — 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 93 km ENE of Miyako, Japan. Since the mainshock, the USGS has recorded 4 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 39.73°, 143.35°

Earthquake Details

Magnitude
4.4 mb
Depth
35.0 km
shallow crustal
Location
39.7257°N
143.3502°E

Technical Information

Event ID
us7000sgu7
Event Type
earthquake
Status
✓ Reviewed
Significance
298
Stations Used
30
Azimuthal Gap
152.0°
Min Station Distance
2.046°
RMS Residual
0.30 sec
Last Updated
2026-04-29 01:52:00 UTC

Common Questions

How strong was the magnitude 4.4 earthquake near Miyako, Japan?

The magnitude 4.4 earthquake that struck 121 km E of Miyako, Japan on April 29, 2026 at 00:43 UTC had a depth of 35.0 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 4.4 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 4.4 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 93 km ENE of Miyako, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us7000sgu7). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 29, 2026). M4.4 Earthquake 121 km E of Miyako, JapanApril 29, 2026. Retrieved April 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sgu7/