M4.9 Earthquake 28 km NE of Colonia, Micronesia — August 17, 2026
2026-08-17 18:51:11 UTC (1 hour ago) · approx. 3:51 AM UTC+9 local
Felt by 1 person across nearby locations. Aftershock of the M5.4 mainshock.
On August 17, 2026 at 18:51 UTC, a magnitude 4.9 shallow crustal earthquake struck 28 km NE of Colonia, Micronesia, at a depth of 10.0 km and coordinates 9.7108°, 138.2886°. This earthquake was detected by 57 seismic stations with good location accuracy and was assigned a USGS significance rating of 370, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — 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 5.4 mainshock that occurred 1 day ago 19 km NE 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.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
138.2886°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.9 earthquake near Colonia, Micronesia?
The magnitude 4.9 earthquake that struck 28 km NE of Colonia, Micronesia on August 17, 2026 at 18:51 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 9.7108°, 138.2886°, which is 28 km NE of Colonia, Micronesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.4 one earlier?
No. This magnitude 4.9 earthquake is an aftershock of the larger magnitude 5.4 mainshock that occurred earlier 19 km NE of Colonia, Micronesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Authoritative source: USGS event page (event ID: usd0015efc). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, August 17, 2026). M4.9 Earthquake 28 km NE of Colonia, Micronesia — August 17, 2026. Retrieved August 17, 2026 from https://www.earthquaketracker.org/earthquakes/event/usd0015efc/