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M4.2 earthquake 27 km NNW of Rioblanco, Tolima Department, Colombia

A magnitude 4.2 earthquake struck 27 km NNW of Rioblanco, Tolima Department, Colombia at 23:36 local time (04:36 UTC) on 22 Sept 2026, at a depth of 10 km, according to USGS and GFZ.

Reported by 2 agencies · revised from M4.6

Data: USGS, GFZ · updated 2026-10-04 03:55 UTC · reviewed

Magnitude
4.2light
body-wave magnitude (mb)
revised from 4.6
Depth
10 km
Status
Reviewed
Origin time
2026-09-23 04:36:36 UTC
Local: 22 Sept 2026, 23:36:36 (America/Bogota)
Epicentre
3.732° N, 75.778° W

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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

Distance and estimated shaking at nearby places
PlaceDistanceEst. shaking
RioblancoTolima Department, Colombia · pop. 19,09027 kmIIIWeak
ChaparralTolima Department, Colombia · pop. 19,98233 kmIIIWeak
El CerritoValle del Cauca Department, Colombia · pop. 38,39059 kmIIWeak
TuluáValle del Cauca Department, Colombia · pop. 221,68461 kmIIWeak
PlanadasTolima Department, Colombia · pop. 21,55761 kmIIWeak
Guadalajara de BugaValle del Cauca Department, Colombia · pop. 114,31661 kmIIWeak
PalmiraValle del Cauca Department, Colombia · pop. 312,51962 kmIIWeak
CaliValle del Cauca Department, Colombia · pop. 2,392,87789 kmIIWeak

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.

AgencyMagnitudeDepthEpicentreTime offsetStatus
GFZGFZ via GEOFON, GFZ Helmholtz Centre for Geosciences4.6 mb52.7 km3.77° N, 75.52° W+5.5 sAutomatic
USGSheadlineUSGS NEIC via U.S. Geological Survey4.2 mbwas 4.410 km3.73° N, 75.78° W–Reviewed · 1 revision

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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

8 later earthquakes within 30 km; the largest was M4.6 9 days ago. 4 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M4.2

8 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
0.174.210
4.464.210
36.174.610
36.634.210
47.344.210
50.724.557
124.064.310
161.234.510
  1. 4.622 km NNW of Rioblanco, Tolima Department, Colombia09-24 16:46
  2. 4.515 km SW of San Antonio, Tolima Department, Colombia09-29 21:50
  3. 4.526 km NNW of Rioblanco, Tolima Department, Colombia09-25 07:19
  4. 4.327 km WNW of Chaparral, Tolima Department, Colombia09-28 08:39
  5. 4.225 km SSW of Roncesvalles, Tolima Department, Colombia09-23 04:46
  6. 4.218 km SW of Roncesvalles, Tolima Department, Colombia09-23 09:04
  7. 4.229 km WSW of Roncesvalles, Tolima Department, Colombia09-24 17:14
  8. 4.219 km WNW of Chaparral, Tolima Department, Colombia09-25 03:57

Did you feel it?

Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.

How strong was the shaking where you were?

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Reports on SeismoAtlas

No reports yet.

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Event id gfz2026sqnl. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: GFZ (geofon:gfz2026sqnl); USGS (usgs:us6000tx0s). Cite as: SeismoAtlas, “M4.2 earthquake 27 km NNW of Rioblanco, Tolima Department, Colombia”, https://seismoatlas.com/earthquake/gfz2026sqnl-m4-2-earthquake-27-km-nnw-of-rioblanco-tolima-department-colombia, data from USGS, GFZ.

JSON: /api/v1/events/gfz2026sqnl. SeismoAtlas is not an official warning service.