QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near San Antonio, PR

No earthquake was likely felt in San Antonio in the 24 hours to 5:22 pm AST (21:22 UTC). The last one was M 4.8, 88 km (55 mi) SW, at 9:19 am AST on 18 September 2026, estimated intensity III (weak) in town; 86 felt reports to USGS. Every earthquake near San Antonio

This page: a magnitude 3.1 earthquake was recorded in San Antonio, PR, at 5:45 am AST on 15 June 2017 (09:45 UTC), 108 km deep.

USGS: 1 km SW of San Antonio, Puerto Rico

26 km (16 mi) W of San Juan, PR · 17 km (11 mi) WNW of Bayamón, PR

5:45 am AST, Jun 15, 2017 · · 108 km deep · released about 1,200 lb of TNT

Every earthquake near San Antonio Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vega Alta Municipio 3 kmDorado Municipio 6 kmVega Baja Municipio 9 kmToa Alta Municipio 11 kmToa Baja Municipio 12 kmCorozal Municipio 16 kmCataño Municipio 17 kmNaranjito Municipio 18 kmMorovis Municipio 18 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
5:45 am AST on 15 June 2017 ()
Where
in San Antonio, PR · earthquakes near San Antonio
Magnitude
M 3.1 (md)
Depth
108 km below the surface
Felt
no reports yet
Nearest
Vega Alta Municipio, 3 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3372 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: Vega Alta, Brenas, Ceiba, Dorado, Monserrate, Toa Baja.

How big was it?

This earthquake released about 1,200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 280,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,800× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 · 30 km WNW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 27 km SE of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 7 km NNW 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 18.4426, -66.3103. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vega Alta Municipio, PR 3 km (2 mi) WSW earthquakes near Vega Alta Municipio
Dorado Municipio, PR 6 km (4 mi) NE earthquakes near Dorado Municipio
Vega Baja Municipio, PR 9 km (6 mi) W earthquakes near Vega Baja Municipio
Toa Alta Municipio, PR 11 km (7 mi) SE earthquakes near Toa Alta Municipio
Toa Baja Municipio, PR 12 km (8 mi) E earthquakes near Toa Baja Municipio
Corozal Municipio, PR 16 km (10 mi) S earthquakes near Corozal Municipio

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

Aftershocks so far

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

  1. 2.8 Puerto Rico region
  2. 2.7 1 km SSE of Brenas, Puerto Rico
  3. 2.9 15 km NNE of Brenas, Puerto Rico
  4. 2.5 5 km ESE of G. L. Garcia, Puerto Rico
  5. 3.0 1 km SE of Corozal, Puerto Rico
  6. 2.8 15 km N of Brenas, Puerto Rico
  7. 2.8 32 km N of Tierras Nuevas Poniente, Puerto Rico
  8. 2.7 26 km N of Tierras Nuevas Poniente, Puerto Rico
  9. 2.9 24 km N of Brenas, Puerto Rico
  10. 2.7 6 km SSW of Corozal, Puerto Rico
  11. 3.1 5 km NE of Orocovis, Puerto Rico
  12. 2.4 2 km W of Aibonito, Puerto Rico
  13. 3.0 6 km NW of Palomas, Puerto Rico
  14. 2.9 2 km NNE of Franquez, Puerto Rico
  15. 2.7 7 km NW of Sumidero, 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.