M3.9 Earthquake 81 km SW of Yonakuni, Japan — August 17, 2024
2024-08-17 18:36:50 UTC (2024-08-17) · approx. 2:36 AM UTC+8 local
On August 17, 2024 at 18:36 UTC, a magnitude 3.9 shallow crustal earthquake struck 81 km SW of Yonakuni, Japan, at a depth of 19.2 km and coordinates 23.9135°, 122.4719°.
Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 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 5.6 mainshock that occurred 12 days ago 74 km S of Yonakuni, 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
122.4719°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.9 earthquake near Yonakuni, Japan?
The magnitude 3.9 earthquake that struck 81 km SW of Yonakuni, Japan on August 17, 2024 at 18:36 UTC had a depth of 19.2 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 3.9 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 74 km S of Yonakuni, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Location
Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000n7n4). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2024, August 17, 2024). M3.9 Earthquake 81 km SW of Yonakuni, Japan — August 17, 2024. Retrieved October 26, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000n7n4/