M4.0 Earthquake 195 km SW of Mazatlán, Mexico — September 19, 2023
2023-09-19 22:18:39 UTC (2023-09-19) · approx. 3:18 PM UTC-7 local
On September 19, 2023 at 22:18 UTC, a magnitude 4.0 shallow crustal earthquake struck 195 km SW of Mazatlán, Mexico, at a depth of 17.1 km and coordinates 21.9271°, -107.6799°.
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Earthquake Details
-107.6799°E
Technical Information
Common Questions
How strong was the magnitude 4.0 earthquake near Mazatlán, Mexico?
The magnitude 4.0 earthquake that struck 195 km SW of Mazatlán, Mexico on September 19, 2023 at 22:18 UTC had a depth of 17.1 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000lcid). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 19, 2023). M4.0 Earthquake 195 km SW of Mazatlán, Mexico — September 19, 2023. Retrieved December 2, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lcid/