M3.7 Earthquake 4 km ESE of Mobara, Japan — May 29, 2026
2026-05-29 21:38:32 UTC (2026-05-29) · approx. 6:38 AM UTC+9 local
On May 29, 2026 at 21:38 UTC, a magnitude 3.7 shallow crustal earthquake struck 4 km ESE of Mobara, Japan, at a depth of 36.3 km and coordinates 35.4153°, 140.3439°.
Physical scale: An earthquake of magnitude 3.7 releases seismic energy equivalent to roughly 5.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 215 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 5.8 mainshock that occurred 21 days ago 3 km SE of Yokoshiba, 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
140.3439°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.7 earthquake near Mobara, Japan?
The magnitude 3.7 earthquake that struck 4 km ESE of Mobara, Japan on May 29, 2026 at 21:38 UTC had a depth of 36.3 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 3.7 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.8 one earlier?
No. This magnitude 3.7 earthquake is an aftershock of the larger magnitude 5.8 mainshock that occurred earlier 3 km SE of Yokoshiba, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Location
Understanding This Data
Magnitude 3.7 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000sql6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, May 29, 2026). M3.7 Earthquake 4 km ESE of Mobara, Japan — May 29, 2026. Retrieved July 2, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sql6/