QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

0 km SE of San Antonio, Puerto Rico

· 99 km deep · released about 1,600 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vega Alta Municipio 4 kmDorado Municipio 5 kmVega Baja Municipio 10 kmToa Alta Municipio 11 kmToa Baja Municipio 11 kmCataño Municipio 16 kmCorozal Municipio 16 kmBayamón Municipio 17 kmNaranjito 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
Magnitude
M 3.1 (md)
Depth
99 km below the surface
Felt
2 reports · strongest reported intensity I
Nearest
Vega Alta Municipio, 4 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2077 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× 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.

Where

Epicentre 18.4458, -66.2990. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Vega Alta Municipio, PR 4 km (3 mi) ENE of here earthquakes near Vega Alta Municipio
Dorado Municipio, PR 5 km (3 mi) SW of here earthquakes near Dorado Municipio
Vega Baja Municipio, PR 10 km (7 mi) E of here earthquakes near Vega Baja Municipio
Toa Alta Municipio, PR 11 km (7 mi) NNW of here earthquakes near Toa Alta Municipio
Toa Baja Municipio, PR 11 km (7 mi) W of here earthquakes near Toa Baja Municipio
Cataño Municipio, PR 16 km (10 mi) W of here earthquakes near Cataño Municipio

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

Aftershocks so far

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

  1. 2.1 1 km WNW of Vega Baja, Puerto Rico
  2. 1.9 0 km W of Parcelas Peñuelas, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.4 on 2018-12-09 — it released about 75 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.