QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

Earthquake near Pájaros, PR

No earthquake was likely felt in Pájaros in the 24 hours to 6:02 pm AST (22:02 UTC). The last one was M 4.8, 91 km (56 mi) WSW, at 9:19 am AST on 18 September 2026, estimated intensity III (weak) in town; 86 felt reports to USGS. Every earthquake near Pájaros

This page: a magnitude 3.3 earthquake was recorded 6 km (4 mi) southeast of Pájaros, PR, at 4:00 pm AST on 19 December 2020 (20:00 UTC), 62 km deep. 2 people have reported feeling it to USGS.

USGS: 5 km SE of Pájaros, Puerto Rico

5 km (3 mi) SSW of Bayamón, PR

4:00 pm AST, Dec 19, 2020 · · 62 km deep · released about 1.2 tons of TNT

Every earthquake near Pájaros Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Bayamón Municipio 2 kmGuaynabo Municipio 7 kmToa Alta Municipio 8 kmNaranjito Municipio 9 kmAguas Buenas Municipio 10 kmCataño Municipio 13 kmComerío Municipio 13 kmToa Baja Municipio 14 kmSan Juan Municipio 15 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
4:00 pm AST on 19 December 2020 ()
Where
6 km (4 mi) southeast of Pájaros, PR · earthquakes near Pájaros
Magnitude
M 3.3 (md)
Depth
62 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Bayamón Municipio, 2 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1556 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 it was probably too small to be felt, even directly above it. In Pájaros, 6 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.

Earthquakes near other towns within 30 km: Guaynabo, Mucarabones, Bayamón, Naranjito, Candelaria, Galateo.

How big was it?

This earthquake released about 1.2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 140,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,400× the energy of this one
  4. This earthquake M 3.3 about 1.2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.5× 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 4.6 on 2019-03-12 — about 99 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 48 km WNW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 9 km SSE of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 25 km NW 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 18.3340, -66.1773. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Bayamón Municipio, PR 2 km (1 mi) NNE earthquakes near Bayamón Municipio
Guaynabo Municipio, PR 7 km (4 mi) E earthquakes near Guaynabo Municipio
Toa Alta Municipio, PR 8 km (5 mi) WNW earthquakes near Toa Alta Municipio
Naranjito Municipio, PR 9 km (6 mi) WSW earthquakes near Naranjito Municipio
Aguas Buenas Municipio, PR 10 km (6 mi) SSE earthquakes near Aguas Buenas Municipio
Cataño Municipio, PR 13 km (8 mi) NNE earthquakes near Cataño Municipio

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

Aftershocks so far

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

  1. 3.1 10 km NNW of Sabana, Puerto Rico
  2. 2.0 5 km E of Orocovis, Puerto Rico
  3. 3.2 4 km SE of Cataño, Puerto Rico
  4. 3.1 19 km NNE of San Juan, Puerto Rico
  5. 2.9 16 km NNE of Suárez, Puerto Rico
  6. 2.0 2 km E of Vázquez, Puerto Rico
  7. 2.6 33 km N of San Juan, Puerto Rico
  8. 1.6 0 km SSE of Parcelas Peñuelas, Puerto Rico
  9. 1.5 4 km N of Coto Laurel, Puerto Rico
  10. 2.1 1 km WNW of Vega Baja, Puerto Rico
  11. 2.4 2 km ESE of Santa Isabel, Puerto Rico
  12. 1.9 0 km W of Parcelas Peñuelas, Puerto Rico
  13. 3.1 0 km SE of San Antonio, Puerto Rico
  14. 2.4 2 km S of Guaynabo, 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.