M4.9 Earthquake near Central Peru — September 22, 2023
2023-09-22 02:11:55 UTC (2023-09-22) · approx. 9:11 PM UTC-5 local
Aftershock of the M5.6 mainshock.
On September 22, 2023 at 02:11 UTC, a magnitude 4.9 intermediate depth earthquake struck near Central Peru, at a depth of 137.5 km and coordinates -8.7467°, -74.4310°. This earthquake was detected by 78 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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 5.6 mainshock that occurred 24 days ago 15 km ENE of San Fernando, Peru. Since the mainshock, the USGS has recorded 0 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 Peru, a region characterized by the northern Peru-Chile subduction zone, complicated by the subduction of the Nazca Ridge. The nearest mapped fault system is the Peru-Chile Trench. View all earthquakes in Peru.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
-74.4310°E
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Common Questions
How strong was the magnitude 4.9 earthquake near Central Peru?
The magnitude 4.9 earthquake that struck near Central Peru on September 22, 2023 at 02:11 UTC had a depth of 137.5 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -8.7467°, -74.4310°, which is near Central Peru. View all earthquakes in Peru.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 4.9 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 15 km ENE of San Fernando, Peru. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Peru had earthquakes this big before?
The largest recorded earthquake in Peru was the M8.0 Arequipa earthquake of June 23, 2001. Today's magnitude 4.9 event is significantly smaller than that historical record.
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Authoritative source: USGS event page (event ID: us7000kxa3). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 22, 2023). M4.9 Earthquake near Central Peru — September 22, 2023. Retrieved December 2, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kxa3/