M4.6 Earthquake 41 km W of Mosteiros, Portugal — October 29, 2026
2026-10-29 07:54:06 UTC (40 min ago) · approx. 5:54 AM UTC-2 local
Aftershock of the M5.1 mainshock.
On October 29, 2026 at 07:54 UTC, a magnitude 4.6 shallow crustal earthquake struck 41 km W of Mosteiros, Portugal, at a depth of 10.0 km and coordinates 37.9065°, -26.2963°. This earthquake was detected by 24 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 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 8 days ago 39 km W of Mosteiros, Portugal. 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.
Earthquake Details
-26.2963°E
Technical Information
Common Questions
How strong was the magnitude 4.6 earthquake near Mosteiros, Portugal?
The magnitude 4.6 earthquake that struck 41 km W of Mosteiros, Portugal on October 29, 2026 at 07:54 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 37.9065°, -26.2963°, which is 41 km W of Mosteiros, Portugal.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 39 km W of Mosteiros, Portugal. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Authoritative source: USGS event page (event ID: us7000tty0). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, October 29, 2026). M4.6 Earthquake 41 km W of Mosteiros, Portugal — October 29, 2026. Retrieved October 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tty0/