M5.3 earthquake 47 km NNE of Chilecito, La Rioja, Argentina
A magnitude 5.3 earthquake struck 47 km NNE of Chilecito, La Rioja, Argentina at 06:21 local time (09:21 UTC) on 23 Sept 2026, at a depth of 121 km, according to USGS and GFZ.
Reported by 2 agencies · 4 reports to USGS “Did You Feel It?”
Data: USGS, GFZ · updated 2026-10-15 13:56 UTC · reviewed
- Magnitude
- 5.3moderate
moment magnitude (W phase) (mww) - Depth
- 121.4 km
- Status
- Reviewed
- Origin time
- 2026-09-23 09:21:14 UTC
- Local: 23 Sept 2026, 06:21:14 (America/Argentina/La Rioja)
- Epicentre
- 28.770° S, 67.302° W
Circles show this event and others within 56 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map
Nearby places
| Place | Distance | Est. shaking |
|---|---|---|
| ChilecitoLa Rioja, Argentina · pop. 42,248 | 47 km | IIIWeak |
| AimogastaLa Rioja, Argentina · pop. 16,625 | 53 km | IIIWeak |
| La RiojaArgentina · pop. 178,872 | 83 km | IIIWeak |
| San Miguel de TucumánTucuman, Argentina · pop. 548,866 | 299 km | IIWeak |
| Santiago del EsteroArgentina · pop. 252,192 | 317 km | IIWeak |
Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more. Likely felt out to about 128 km.
Every agency's solution
Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS, which has been reviewed by an analyst.
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How big was it?
Felt by most people over a wide area. Can damage poorly built structures close to the epicentre.
It released roughly the energy of 1.3 kt of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 121 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.
M5.3 releases about 32× the energy of M4.3, and its waves are about 10× taller on a seismogram. Energy: 1.3 kt of TNT vs 43 t of TNT.
Each square is the energy of one M4.3. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
1 later earthquake within 56 km; the largest was M4.4 2 days ago. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M5.3
1 later earthquake nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 473.72 | 4.4 | 128 |
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports close 14 days after an earthquake.
Event id gfz2026sqwv. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: GFZ (geofon:gfz2026sqwv); USGS (usgs:us6000tx29). Cite as: SeismoAtlas, “M5.3 earthquake 47 km NNE of Chilecito, La Rioja, Argentina”, https://seismoatlas.com/earthquake/gfz2026sqwv-m5-3-earthquake-47-km-nne-of-chilecito-la-rioja-argentina, data from USGS, GFZ.
JSON: /api/v1/events/gfz2026sqwv. SeismoAtlas is not an official warning service.