M4.3 Earthquake 10 km SSE of Hasaki, Japan — October 28, 2026
2026-10-28 20:22:30 UTC (2 hours ago) · approx. 5:22 AM UTC+9 local
On October 28, 2026 at 20:22 UTC, a magnitude 4.3 shallow crustal earthquake struck 10 km SSE of Hasaki, Japan, at a depth of 26.0 km and coordinates 35.6474°, 140.8850°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.5 mainshock that occurred 7 hours ago 5 km ESE of Asahi, Japan. Since the mainshock, the USGS has recorded 3 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
140.8850°E
Technical Information
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Common Questions
How strong was the magnitude 4.3 earthquake near Hasaki, Japan?
The magnitude 4.3 earthquake that struck 10 km SSE of Hasaki, Japan on October 28, 2026 at 20:22 UTC had a depth of 26.0 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 4.3 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.5 one earlier?
No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.5 mainshock that occurred earlier 5 km ESE of Asahi, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000ttts). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, October 28, 2026). M4.3 Earthquake 10 km SSE of Hasaki, Japan — October 28, 2026. Retrieved October 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000ttts/