4.5

M4.5 Earthquake 224 km NNE of Colonia, Micronesia — March 27, 2026

2026-03-27 19:25:44 UTC (2026-03-27) · approx. 4:25 AM UTC+9 local

Aftershock of the M5.9 mainshock.

MagnitudeM4.5(mb)
Time19:25 UTC≈ 4:25 AM UTC+9
Depth10.0 kmshallow crustal
Coordinates11.367°, 138.968°
Felt byNo felt reports
Status✓ Reviewed by USGS

On March 27, 2026 at 19:25 UTC, a magnitude 4.5 shallow crustal earthquake struck 224 km NNE of Colonia, Micronesia, at a depth of 10.0 km and coordinates 11.3673°, 138.9675°. This earthquake was detected by 40 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 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 5.9 mainshock that occurred 25 days ago 244 km NNE of Colonia, Micronesia. 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.

Map showing earthquake epicenter at 11.37°, 138.97°

Earthquake Details

Magnitude
4.5 mb
Depth
10.0 km
shallow crustal
Location
11.3673°N
138.9675°E

Technical Information

Event ID
us6000sn9b
Event Type
earthquake
Status
✓ Reviewed
Significance
312
Stations Used
40
Azimuthal Gap
90.0°
Min Station Distance
13.898°
RMS Residual
0.85 sec
Last Updated
2026-06-10 15:14:48 UTC

Common Questions

How strong was the magnitude 4.5 earthquake near Colonia, Micronesia?

The magnitude 4.5 earthquake that struck 224 km NNE of Colonia, Micronesia on March 27, 2026 at 19:25 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 11.3673°, 138.9675°, which is 224 km NNE of Colonia, Micronesia.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.9 one earlier?

No. This magnitude 4.5 earthquake is an aftershock of the larger magnitude 5.9 mainshock that occurred earlier 244 km NNE of Colonia, Micronesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Actions

View on USGSDid You Feel It?

Authoritative source: USGS event page (event ID: us6000sn9b). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, March 27, 2026). M4.5 Earthquake 224 km NNE of Colonia, Micronesia — March 27, 2026. Retrieved June 10, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000sn9b/