M4.3 earthquake 19 km NE of Barreal, San Juan, Argentina
A magnitude 4.3 earthquake struck 19 km NE of Barreal, San Juan, Argentina at 20:23 local time (23:23 UTC) on 27 Oct 2026, at a depth of 120 km, according to USGS.
Data: USGS · updated 2026-11-06 01:28 UTC · reviewed
- Magnitude
- 4.3light
body-wave magnitude (mb) - Depth
- 119.6 km
- Status
- Reviewed
- Origin time
- 2026-10-27 23:23:57 UTC
- Local: 27 Oct 2026, 20:23:57 (America/Argentina/San Juan)
- Epicentre
- 31.544° S, 69.317° W
Circles show this event and others within 30 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 |
|---|---|---|
| BarrealSan Juan, Argentina · pop. 5,062 | 19 km | IIWeak |
| PocitoSan Juan, Argentina · pop. 40,969 | 71 km | INot felt |
| RawsonSan Juan, Argentina · pop. 130,258 | 74 km | INot felt |
| San JuanArgentina · pop. 109,123 | 75 km | INot felt |
| ChimbasSan Juan, Argentina · pop. 73,829 | 75 km | INot felt |
| SantiagoSantiago Metropolitan, Chile · pop. 4,837,295 | 247 km | INot felt |
| MaipúSantiago Metropolitan, Chile · pop. 503,635 | 258 km | INot felt |
| Puente AltoSantiago Metropolitan, Chile · pop. 568,106 | 258 km | INot felt |
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.
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.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGSheadlineUSGS NEIC via U.S. Geological Survey | 4.3 mb | 119.6 km | 31.54° S, 69.32° W | – | Reviewed · 1 revision |
How big was it?
Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.
It released roughly the energy of 43 t 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 120 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.
M4.3 releases about 32× the energy of M3.3, and its waves are about 10× taller on a seismogram. Energy: 43 t of TNT vs 1.3 t of TNT.
Each square is the energy of one M3.3. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
2 later earthquakes within 30 km; the largest was M4.7 1 day ago. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M4.3
2 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 351.38 | 4.7 | 105 |
| 367.36 | 3.6 | 118 |
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.
Reports on SeismoAtlas
No reports yet.
Event id us7000ttkf. First recorded here 28 Oct 2026, 00:39:23 UTC. Solutions: USGS (usgs:us7000ttkf). Cite as: SeismoAtlas, “M4.3 earthquake 19 km NE of Barreal, San Juan, Argentina”, https://seismoatlas.com/earthquake/us7000ttkf-m4-3-earthquake-19-km-ne-of-barreal-san-juan-argentina, data from USGS.
JSON: /api/v1/events/us7000ttkf. SeismoAtlas is not an official warning service.