M4.2 earthquake 18 km SW of Roncesvalles, Tolima Department, Colombia
A magnitude 4.2 earthquake struck 18 km SW of Roncesvalles, Tolima Department, Colombia at 04:04 local time (09:04 UTC) on 23 Sept 2026, at a depth of 10 km, according to USGS.
Data: USGS · updated 2026-09-24 08:26 UTC · reviewed
- Magnitude
- 4.2light
body-wave magnitude (mb) - Depth
- 10 km
- Status
- Reviewed
- Origin time
- 2026-09-23 09:04:13 UTC
- Local: 23 Sept 2026, 04:04:13 (America/Bogota)
- Epicentre
- 3.915° N, 75.732° 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 |
|---|---|---|
| RoncesvallesTolima Department, Colombia · pop. 6,340 | 18 km | IVLight |
| San AntonioTolima Department, Colombia · pop. 5,185 | 28 km | IIIWeak |
| SevillaValle del Cauca Department, Colombia · pop. 43,738 | 45 km | IIIWeak |
| CaicedoniaValle del Cauca Department, Colombia · pop. 32,417 | 47 km | IIIWeak |
| TuluáValle del Cauca Department, Colombia · pop. 221,684 | 55 km | IIWeak |
| La TebaidaQuindío Department, Colombia · pop. 27,098 | 60 km | IIWeak |
| ArmeniaQuindío Department, Colombia · pop. 304,314 | 70 km | IIWeak |
| PalmiraValle del Cauca Department, Colombia · pop. 312,519 | 76 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 53 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.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGSheadlineUSGS NEIC via U.S. Geological Survey | 4.2 mb | 10 km | 3.91° N, 75.73° W | – | Reviewed |
How big was it?
Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.
It released roughly the energy of 30 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 10 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M4.2 releases about 32× the energy of M3.2, and its waves are about 10× taller on a seismogram. Energy: 30 t of TNT vs 951 kg of TNT.
Each square is the energy of one M3.2. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
5 later earthquakes within 30 km; the largest was M4.6 4 days ago. 8 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M4.2
5 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 31.71 | 4.6 | 10 |
| 32.17 | 4.2 | 10 |
| 46.26 | 4.5 | 57 |
| 69.57 | 4.6 | 10 |
| 119.60 | 4.5 | 31 |
- 4.622 km NNW of Rioblanco, Tolima Department, Colombia09-24 16:46
- 4.626 km W of Roncesvalles, Tolima Department, Colombia09-26 06:38
- 4.520 km N of Rioblanco, Tolima Department, Colombia09-28 08:39
- 4.526 km NNW of Rioblanco, Tolima Department, Colombia09-25 07:19
- 4.229 km WSW of Roncesvalles, Tolima Department, Colombia09-24 17:14
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
Event id us6000tx28. First recorded here 28 Sept 2026, 17:32:10 UTC. Solutions: USGS (usgs:us6000tx28). Cite as: SeismoAtlas, “M4.2 earthquake 18 km SW of Roncesvalles, Tolima Department, Colombia”, https://seismoatlas.com/earthquake/us6000tx28-m4-2-earthquake-18-km-sw-of-roncesvalles-tolima-department-colombia, data from USGS.
JSON: /api/v1/events/us6000tx28. SeismoAtlas is not an official warning service.