M4.4 Earthquake 45 km SE of Los Andes, Chile — September 6, 2021
2021-09-06 22:36:24 UTC (2021-09-06) · approx. 5:36 PM UTC-5 local
Felt by 19 people across nearby locations. Aftershock of the M5.2 mainshock.
On September 6, 2021 at 22:36 UTC, a magnitude 4.4 intermediate depth earthquake struck 45 km SE of Los Andes, Chile, at a depth of 110.5 km and coordinates -33.0917°, -70.2201°.
Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — 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 5.2 mainshock that occurred 2 days ago 28 km NE of Villa Presidente Frei, Chile. 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 Chile, a region characterized by the Peru-Chile Trench, where the Nazca Plate subducts beneath South America at 65-80 mm per year. The nearest mapped fault system is the Peru-Chile Trench. View all earthquakes in Chile.
Learn more: Magnitude scale · Aftershock sequences
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 19 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-70.2201°E
Technical Information
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Common Questions
How strong was the magnitude 4.4 earthquake near Los Andes, Chile?
The magnitude 4.4 earthquake that struck 45 km SE of Los Andes, Chile on September 6, 2021 at 22:36 UTC had a depth of 110.5 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -33.0917°, -70.2201°, which is 45 km SE of Los Andes, Chile. View all earthquakes in Chile.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.4 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.2 one earlier?
No. This magnitude 4.4 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 28 km NE of Villa Presidente Frei, Chile. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Chile had earthquakes this big before?
The largest recorded earthquake in Chile was the M9.5 Great Chilean earthquake of May 22, 1960. Today's magnitude 4.4 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000f8q1). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 6, 2021). M4.4 Earthquake 45 km SE of Los Andes, Chile — September 6, 2021. Retrieved August 8, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000f8q1/