M4.3 Earthquake in the Mariana Islands region — February 21, 2026
2026-02-21 23:10:55 UTC (2026-02-21) · approx. 9:10 AM UTC+10 local
On February 21, 2026 at 23:10 UTC, a magnitude 4.3 shallow crustal earthquake struck in the Mariana Islands region, at a depth of 19.2 km and coordinates 21.3279°, 145.8624°.
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.
Earthquake Details
145.8624°E
Technical Information
Common Questions
How strong was the magnitude 4.3 earthquake in the Mariana Islands region?
The magnitude 4.3 earthquake that struck in the Mariana Islands region on February 21, 2026 at 23:10 UTC had a depth of 19.2 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.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Actions
Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000sapn). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, February 21, 2026). M4.3 Earthquake in the Mariana Islands region — February 21, 2026. Retrieved May 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000sapn/