QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 12:59 pm AST (16:59 UTC). The last one was M 4.1, 99 km (62 mi) SE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near San Juan

This page: a magnitude 2.3 earthquake was recorded 37 km (23 mi) north-northwest of San Juan, PR, at 3:16 pm AST on 30 August 2018 (19:16 UTC), 12 km deep.

USGS: 36 km N of Dorado, Puerto Rico

45 km (28 mi) NNW of San Juan, PR

3:16 pm AST, Aug 30, 2018 · · 12 km deep · released about 98 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 35 kmToa Baja Municipio 36 kmCataño Municipio 38 kmVega Alta Municipio 40 kmVega Baja Municipio 41 kmSan Juan Municipio 43 kmToa Alta Municipio 46 kmLoíza Municipio 47 kmManatí Municipio 47 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
3:16 pm AST on 30 August 2018 ()
Where
37 km (23 mi) north-northwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.3 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 35 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2926 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 16 km (10 mi) from the epicentre. In San Juan, 37 km away, the estimate is intensity II (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.

How big was it?

This earthquake released about 98 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.8× the energy of this one
  4. This earthquake M 2.3 about 98 lb of TNT

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 4.8 on 2017-08-18 — about 4,900 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 44 km WSW of this epicentre
  2. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 40 km NW of this epicentre
  3. 5.1 66 km N of Brenas, Puerto Rico · 36 km NNW of this epicentre
  4. 5.0 3 km N of Brenas, Puerto Rico · 34 km SSW 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 18.7818, -66.2163. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 35 km (21 mi) S earthquakes near Dorado Municipio
Toa Baja Municipio, PR 36 km (22 mi) S earthquakes near Toa Baja Municipio
Cataño Municipio, PR 38 km (24 mi) S earthquakes near Cataño Municipio
Vega Alta Municipio, PR 40 km (25 mi) SSW earthquakes near Vega Alta Municipio
Vega Baja Municipio, PR 41 km (26 mi) SSW earthquakes near Vega Baja Municipio
San Juan Municipio, PR 43 km (27 mi) SSE earthquakes near San Juan Municipio

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

Aftershocks so far

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

  1. 2.3 3 km SSW of Vega Alta, Puerto Rico
  2. 2.0 2 km SW of Corozal, Puerto Rico
  3. 2.8 40 km N of Brenas, Puerto Rico
  4. 2.8 Puerto Rico region
  5. 2.5 74 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.0 74 km N of Brenas, Puerto Rico
  7. 2.6 Puerto Rico region
  8. 2.9 61 km N of Tierras Nuevas Poniente, Puerto Rico
  9. 2.9 65 km NNE of Arecibo, Puerto Rico
  10. 2.5 55 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 2.3 71 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 2.8 61 km N of Tierras Nuevas Poniente, Puerto Rico
  13. 2.9 67 km N of Tierras Nuevas Poniente, Puerto Rico
  14. 2.4 70 km N of Tierras Nuevas Poniente, Puerto Rico
  15. 2.4 26 km N 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.