M5.1 Earthquake 121 km WSW of Puerto Madero, Mexico — October 21, 2023
2023-10-21 17:10:01 UTC (2023-10-21) · approx. 11:10 AM UTC-6 local
Aftershock of the M5.7 mainshock.
On October 21, 2023 at 17:10 UTC, a magnitude 5.1 shallow crustal earthquake struck 121 km WSW of Puerto Madero, Mexico, at a depth of 9.8 km and coordinates 14.1937°, -93.4100°. This earthquake was detected by 229 seismic stations with good location accuracy and was assigned a USGS significance rating of 400, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 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 5.7 mainshock that occurred 5 days ago 95 km SW of Puerto Madero, Mexico. Since the mainshock, the USGS has recorded 5 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Mexico, a region characterized by the Middle America Trench, where the Cocos Plate subducts beneath the North American Plate. The nearest mapped fault system is the Middle America Trench. View all earthquakes in Mexico.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
-93.4100°E
Technical Information
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Common Questions
How strong was the magnitude 5.1 earthquake near Puerto Madero, Mexico?
The magnitude 5.1 earthquake that struck 121 km WSW of Puerto Madero, Mexico on October 21, 2023 at 17:10 UTC had a depth of 9.8 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 14.1937°, -93.4100°, which is 121 km WSW of Puerto Madero, Mexico. View all earthquakes in Mexico.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.1 earthquakes can continue for days to weeks and gradually diminish over time.
Is this the same earthquake as the M5.7 one earlier?
No. This magnitude 5.1 earthquake is an aftershock of the larger magnitude 5.7 mainshock that occurred earlier 95 km SW of Puerto Madero, Mexico. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Mexico had earthquakes this big before?
The largest recorded earthquake in Mexico was the M8.1 Chiapas earthquake of September 8, 2017. Today's magnitude 5.1 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000lh6m). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 21, 2023). M5.1 Earthquake 121 km WSW of Puerto Madero, Mexico — October 21, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lh6m/