M5.5 Earthquake near southern Mid-Atlantic Ridge — October 29, 2025
2025-10-29 06:16:45 UTC (2025-10-29) · approx. 5:16 AM UTC-1 local
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On October 29, 2025 at 06:16 UTC, a magnitude 5.5 shallow crustal earthquake struck near southern Mid-Atlantic Ridge, at a depth of 10.0 km and coordinates -47.2049°, -12.2160°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 105 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 465, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 km — a useful intuition for the size of the slip patch on the fault.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
-12.2160°E
Technical Information
Common Questions
How strong was the magnitude 5.5 earthquake near southern Mid-Atlantic Ridge?
The magnitude 5.5 earthquake that struck near southern Mid-Atlantic Ridge on October 29, 2025 at 06:16 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -47.2049°, -12.2160°, which is near southern Mid-Atlantic Ridge.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks 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.
Authoritative source: USGS event page (event ID: us6000rk4f). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, October 29, 2025). M5.5 Earthquake near southern Mid-Atlantic Ridge — October 29, 2025. Retrieved May 26, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rk4f/