QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

104 km NNW of San Antonio, Puerto Rico

Yes. A magnitude 3.5 earthquake was recorded 104 km NNW of San Antonio, Puerto Rico, at 10:33 am AST on 1 November 2026 (14:33 UTC), 28 km deep.

· 28 km deep · released about 2.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguadilla Municipio 105 kmIsabela Municipio 108 kmQuebradillas Municipio 113 kmAguada Municipio 116 kmCamuy Municipio 118 kmMoca Municipio 118 kmRincón Municipio 120 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
Magnitude
M 3.5 (md)
Depth
28 km below the surface
Felt
no reports yet
Nearest
Aguadilla Municipio, 105 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 10 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 54 km (34 mi) from the epicentre. 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.

How big was it?

This earthquake released about 2.3 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 72,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,300× the energy of this one
  4. This earthquake M 3.5 about 2.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.9× 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 6.0 on 2019-09-24 — about 6,500 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 93 km NNW of San Antonio, Puerto Rico · 11 km SSE of this epicentre
  2. 6.0 81 km N of Isabela, Puerto Rico · 46 km ESE of this epicentre
  3. 6.0 67 km NNW of San Antonio, Puerto Rico · 38 km S of this epicentre
  4. 5.7 88 km N of San Antonio, Puerto Rico · 17 km SSE of this epicentre
  5. 5.5 65 km N of Isabela, Puerto Rico · 43 km SSE 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 19.4130, -67.3145. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguadilla Municipio, PR 105 km (65 mi) S earthquakes near Aguadilla Municipio
Isabela Municipio, PR 108 km (67 mi) SSE earthquakes near Isabela Municipio
Quebradillas Municipio, PR 113 km (70 mi) SSE earthquakes near Quebradillas Municipio
Aguada Municipio, PR 116 km (72 mi) S earthquakes near Aguada Municipio
Camuy Municipio, PR 118 km (73 mi) SSE earthquakes near Camuy Municipio
Moca Municipio, PR 118 km (73 mi) SSE earthquakes near Moca 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. 3.7 124 km NNE of Punta Cana, Dominican Republic
  2. 3.2 70 km NNW of San Antonio, Puerto Rico
  3. 3.2 106 km N of Isabela, 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.