M4.2 Earthquake 101 km ENE of Miyako, Japan — January 21, 2024
2024-01-21 21:30:21 UTC (2024-01-21) · approx. 7:30 AM UTC+10 local
On January 21, 2024 at 21:30 UTC, a magnitude 4.2 shallow crustal earthquake struck 101 km ENE of Miyako, Japan, at a depth of 35.0 km and coordinates 39.9079°, 143.0782°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 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 5.1 mainshock that occurred 11 days ago 103 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.
Earthquake Details
143.0782°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Miyako, Japan?
The magnitude 4.2 earthquake that struck 101 km ENE of Miyako, Japan on January 21, 2024 at 21:30 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 4.2 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 103 km ENE of Miyako, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Location
Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000m5az). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2024, January 21, 2024). M4.2 Earthquake 101 km ENE of Miyako, Japan — January 21, 2024. Retrieved March 29, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000m5az/