M4.4 Earthquake 136 km E of Yamada, Japan — September 30, 2023
2023-09-30 18:09:00 UTC (2023-09-30) · approx. 4:09 AM UTC+10 local
On September 30, 2023 at 18:09 UTC, a magnitude 4.4 shallow crustal earthquake struck 136 km E of Yamada, Japan, at a depth of 19.6 km and coordinates 39.5154°, 143.5344°.
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 5.3 mainshock that occurred 17 days ago 151 km E of Miyako, Japan. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
143.5344°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.4 earthquake near Yamada, Japan?
The magnitude 4.4 earthquake that struck 136 km E of Yamada, Japan on September 30, 2023 at 18:09 UTC had a depth of 19.6 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 M5.3 one earlier?
No. This magnitude 4.4 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 151 km E of Miyako, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Location
Understanding This Data
Magnitude 4.4 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000lby6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 30, 2023). M4.4 Earthquake 136 km E of Yamada, Japan — September 30, 2023. Retrieved December 9, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lby6/