QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

Earthquake near Trujillo Alto, PR

No earthquake was likely felt in Trujillo Alto in the 24 hours to 5:25 am AST (09:25 UTC). The last one was M 4.1, 83 km (52 mi) ESE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Trujillo Alto

This page: a magnitude 3.5 earthquake was recorded in Trujillo Alto, PR, at 10:35 am AST on 1 August 2022 (14:35 UTC), 125 km deep. 1 person has reported feeling it to USGS.

USGS: 1 km NNW of Trujillo Alto, Puerto Rico

7 km (5 mi) SE of San Juan, PR · 6 km (4 mi) SSW of Carolina, PR

10:35 am AST, Aug 1, 2022 · · 125 km deep · released about 3.1 tons of TNT

Every earthquake near Trujillo Alto Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trujillo Alto Municipio 3 kmCarolina Municipio 6 kmSan Juan Municipio 9 kmGurabo Municipio 11 kmGuaynabo Municipio 11 kmLoíza Municipio 12 kmCanóvanas Municipio 14 kmBayamón Municipio 17 kmCataño Municipio 17 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
10:35 am AST on 1 August 2022 ()
Where
in Trujillo Alto, PR · earthquakes near Trujillo Alto
Magnitude
M 3.5 (md)
Depth
125 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Trujillo Alto Municipio, 3 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1491 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. 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: Carolina, Eleanor Roosevelt, Santa Barbara, Guaynabo, Celada, Canovanas.

How big was it?

This earthquake released about 3.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 55,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,700× the energy of this one
  4. This earthquake M 3.5 about 3.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 6.5× 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 4.1 on 2019-05-02 — about 6.9 times the energy of this one.

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

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 18 km SW of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 38 km WNW 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 18.3635, -66.0098. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Trujillo Alto Municipio, PR 3 km (2 mi) SSE earthquakes near Trujillo Alto Municipio
Carolina Municipio, PR 6 km (4 mi) NE earthquakes near Carolina Municipio
San Juan Municipio, PR 9 km (6 mi) NW earthquakes near San Juan Municipio
Gurabo Municipio, PR 11 km (7 mi) SSE earthquakes near Gurabo Municipio
Guaynabo Municipio, PR 11 km (7 mi) W earthquakes near Guaynabo Municipio
Loíza Municipio, PR 12 km (7 mi) NE earthquakes near Loíza Municipio

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

Aftershocks so far

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

  1. 3.1 22 km NE of Luquillo, Puerto Rico
  2. 3.6 5 km E of Candelero Arriba, Puerto Rico
  3. 3.0 11 km NNW of Brenas, Puerto Rico
  4. 2.8 5 km NNW of Dorado, Puerto Rico
  5. 2.2 3 km N of Orocovis, Puerto Rico
  6. 2.3 2 km SE of Lamboglia, Puerto Rico
  7. 1.9 2 km SSE of Lamboglia, Puerto Rico
  8. 3.6 1 km NNW of San José, Puerto Rico
  9. 3.0 3 km ESE of Cayey, Puerto Rico
  10. 3.0 3 km E of Cayey, Puerto Rico
  11. 1.8 2 km SW of G. L. Garcia, Puerto Rico
  12. 3.0 10 km ENE of Luis M. Cintron, Puerto Rico
  13. 2.1 3 km ENE of Mariano Colón, Puerto Rico
  14. 2.7 4 km SE of Morovis, Puerto Rico
  15. 3.8 5 km ENE of San Juan, 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.