M5.5 Earthquake near central Mid-Atlantic Ridge — November 21, 2023
2023-11-21 05:10:26 UTC (2023-11-21) · approx. 3:10 AM UTC-2 local
Maximum shaking intensity MMI 4.0 (moderate).
On November 21, 2023 at 05:10 UTC, a magnitude 5.5 shallow crustal earthquake struck near central Mid-Atlantic Ridge, at a depth of 10.0 km and coordinates 0.8865°, -28.9827°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 87 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
-28.9827°E
Technical Information
Common Questions
How strong was the magnitude 5.5 earthquake near central Mid-Atlantic Ridge?
The magnitude 5.5 earthquake that struck near central Mid-Atlantic Ridge on November 21, 2023 at 05:10 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 0.8865°, -28.9827°, which is near central 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.
Actions
Authoritative source: USGS event page (event ID: us6000lpra). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, November 21, 2023). M5.5 Earthquake near central Mid-Atlantic Ridge — November 21, 2023. Retrieved February 1, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000lpra/