M4.8 Earthquake 107 km ENE of Miyako, Japan — April 21, 2026
2026-04-21 02:35:47 UTC (2 days ago)
Aftershock of the M5.0 mainshock.
On April 21, 2026 at 02:35 UTC, a magnitude 4.8 shallow crustal earthquake struck 107 km ENE of Miyako, Japan, at a depth of 35.4 km and coordinates 39.8608°, 143.1656°. This earthquake was detected by 53 seismic stations with good location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.0 mainshock that occurred 20 hours ago 93 km ENE of Miyako, Japan. Since the mainshock, the USGS has recorded 2 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
Earthquake Details
143.1656°E
Technical Information
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Common Questions
How strong was the magnitude 4.8 earthquake near Miyako, Japan?
The magnitude 4.8 earthquake that struck 107 km ENE of Miyako, Japan on April 21, 2026 at 02:35 UTC had a depth of 35.4 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 39.8608°, 143.1656°, which is 107 km ENE of Miyako, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 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 4.8 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.
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 4.8 event is significantly smaller than that historical record.
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.