QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 7:46 am AST (11:46 UTC). The last one was M 3.4, 49 km (31 mi) NW, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Arecibo

This page: a magnitude 3.6 earthquake was recorded 25 km (16 mi) west-northwest of Arecibo, PR, at 1:21 pm AST on 12 September 2022 (17:21 UTC), 12 km deep. 22 people have reported feeling it to USGS.

USGS: Puerto Rico region

94 km (59 mi) W of San Juan, PR · 24 km (15 mi) WNW of Arecibo, PR

1:21 pm AST, Sep 12, 2022 · · 12 km deep · released about 4.1 tons of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Quebradillas Municipio 9 kmIsabela Municipio 10 kmCamuy Municipio 14 kmHatillo Municipio 19 kmAguadilla Municipio 22 kmMoca Municipio 23 kmSan Sebastián Municipio 24 kmLares Municipio 31 kmArecibo Municipio 31 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
1:21 pm AST on 12 September 2022 ()
Where
25 km (16 mi) west-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 3.6 (md)
Depth
12 km below the surface
Felt
22 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
Nearest
Quebradillas Municipio, 9 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1453 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 Arecibo, 25 km away, the estimate is intensity III (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: Quebradillas 8 km, intensity III · Isabela 10 km, intensity III · Hatillo 14 km, intensity III · Rafael Hernandez 16 km, intensity III · San Sebastián 23 km, intensity III · Arecibo 25 km, intensity III · Aguadilla 26 km, intensity III · Lares 28 km, intensity III. 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 in our catalogue was M 4.0 on 2020-04-05 — about 4.4 times the energy of this one.

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 18.5423, -66.9445. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Quebradillas Municipio, PR 9 km (5 mi) SSE earthquakes near Quebradillas Municipio
Isabela Municipio, PR 10 km (6 mi) SW earthquakes near Isabela Municipio
Camuy Municipio, PR 14 km (9 mi) SE earthquakes near Camuy Municipio
Hatillo Municipio, PR 19 km (12 mi) SE earthquakes near Hatillo Municipio
Aguadilla Municipio, PR 22 km (14 mi) WSW earthquakes near Aguadilla Municipio
Moca Municipio, PR 23 km (14 mi) SW earthquakes near Moca Municipio

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

Aftershocks so far

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

  1. 2.8 1 km S of Garrochales, Puerto Rico
  2. 3.3 51 km N of Hatillo, Puerto Rico
  3. 2.6 2 km S of Mayagüez, Puerto Rico
  4. 3.0 28 km NW of Rincón, Puerto Rico
  5. 3.3 18 km N of San Antonio, Puerto Rico
  6. 3.0 0 km SSW of Rincón, Puerto Rico
  7. 3.0 35 km NNW of San Antonio, Puerto Rico
  8. 2.6 5 km W of Maricao, Puerto Rico
  9. 2.7 4 km NW of Hormigueros, Puerto Rico
  10. 2.7 13 km N of Carrizales, Puerto Rico
  11. 3.0 4 km NW of Hormigueros, Puerto Rico
  12. 2.4 4 km SSW of Mayagüez, Puerto Rico
  13. 2.5 5 km E of Mayagüez, Puerto Rico
  14. 3.3 37 km N of San Antonio, Puerto Rico
  15. 2.5 6 km E of Espino, 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.