QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6md

Earthquake near Cabo Rojo, PR

No earthquake was likely felt in Cabo Rojo in the 24 hours to 12:12 pm AST (16:12 UTC). The last one was M 2.1, 9 km (6 mi) SSE, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Cabo Rojo

This page: a magnitude 3.6 earthquake was recorded 50 km (31 mi) west-southwest of Cabo Rojo, PR, at 12:08 am AST on 5 September 2020 (04:08 UTC), 10 km deep.

USGS: 43 km W of Pole Ojea, Puerto Rico

55 km (34 mi) WSW of Mayagüez, PR · 103 km (64 mi) W of Ponce, PR

12:08 am AST, Sep 5, 2020 · · 10 km deep · released about 4.1 tons of TNT

Every earthquake near Cabo Rojo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mayagüez Municipio 33 kmCabo Rojo Municipio 44 kmHormigueros Municipio 54 kmRincón Municipio 55 kmLajas Municipio 59 kmAñasco Municipio 61 kmSan Germán Municipio 61 kmAguada Municipio 63 kmSabana Grande Municipio 70 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
12:08 am AST on 5 September 2020 ()
Where
50 km (31 mi) west-southwest of Cabo Rojo, PR · earthquakes near Cabo Rojo
Magnitude
M 3.6 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Mayagüez Municipio, 33 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2185 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 70 km (43 mi) from the epicentre. In Cabo Rojo, 50 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Pole Ojea 44 km, intensity II · Puerto Real 45 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 4.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 42,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,300× the energy of this one
  4. This earthquake M 3.6 about 4.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 8.5× more

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 4.3 on 2019-09-05 — about 10 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.2 19 km SW of Stella, Puerto Rico · 34 km NE of this epicentre
  2. 5.1 21 km SW of Stella, Puerto Rico · 33 km NE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 17.9668, -67.5980. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mayagüez Municipio, PR 33 km (21 mi) WNW earthquakes near Mayagüez Municipio
Cabo Rojo Municipio, PR 44 km (27 mi) E earthquakes near Cabo Rojo Municipio
Hormigueros Municipio, PR 54 km (34 mi) ENE earthquakes near Hormigueros Municipio
Rincón Municipio, PR 55 km (34 mi) NE earthquakes near Rincón Municipio
Lajas Municipio, PR 59 km (37 mi) E earthquakes near Lajas Municipio
Añasco Municipio, PR 61 km (38 mi) NE earthquakes near Añasco Municipio

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

3 earthquakes have been recorded within 50 km since this one.

  1. 2.6 51 km WSW of Stella, Puerto Rico
  2. 2.3 10 km NW of Puerto Real, Puerto Rico
  3. 2.5 14 km S of Pole Ojea, Puerto Rico

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.