QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 3:05 pm AST (19:05 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 2.7 earthquake was recorded 36 km (22 mi) north-northeast of San Juan, PR, at 8:03 pm AST on 7 September 2018 (00:03 UTC), 44 km deep.

USGS: Puerto Rico region

41 km (26 mi) NNE of San Juan, PR · 39 km (24 mi) N of Carolina, PR

8:03 pm AST, Sep 7, 2018 · · 44 km deep · released about 360 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Loíza Municipio 36 kmSan Juan Municipio 40 kmCataño Municipio 40 kmCarolina Municipio 41 kmToa Baja Municipio 42 kmDorado Municipio 45 kmRío Grande Municipio 47 kmTrujillo Alto Municipio 48 kmGuaynabo Municipio 49 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
8:03 pm AST on 7 September 2018 ()
Where
36 km (22 mi) north-northeast of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.7 (md)
Depth
44 km below the surface
Felt
no reports yet
Nearest
Loíza Municipio, 36 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2987 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. In San Juan, 36 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 360 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 42,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 30,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.6× the energy of this one
  4. This earthquake M 2.7 about 360 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 in our catalogue was M 4.8 on 2017-08-18 — about 1,300 times the energy of this one.

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 18.7660, -65.9716. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Loíza Municipio, PR 36 km (22 mi) S earthquakes near Loíza Municipio
San Juan Municipio, PR 40 km (25 mi) SSW earthquakes near San Juan Municipio
Cataño Municipio, PR 40 km (25 mi) SSW earthquakes near Cataño Municipio
Carolina Municipio, PR 41 km (26 mi) S earthquakes near Carolina Municipio
Toa Baja Municipio, PR 42 km (26 mi) SW earthquakes near Toa Baja Municipio
Dorado Municipio, PR 45 km (28 mi) SW earthquakes near Dorado Municipio

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

Aftershocks so far

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

  1. 2.6 60 km N of San Juan, Puerto Rico
  2. 1.7 33 km N of San Juan, Puerto Rico
  3. 2.1 6 km NNW of Loíza, Puerto Rico
  4. 2.0 35 km NNW of Brenas, Puerto Rico
  5. 2.8 37 km N of San Juan, Puerto Rico
  6. 2.2 Puerto Rico region
  7. 2.7 72 km N of San Juan, Puerto Rico
  8. 2.5 43 km N of Brenas, Puerto Rico
  9. 1.8 31 km N of Loíza, Puerto Rico
  10. 2.8 40 km N of Brenas, Puerto Rico
  11. 2.8 23 km NNE of Luquillo, Puerto Rico
  12. 2.9 28 km NNE of Luquillo, Puerto Rico
  13. 2.6 Puerto Rico region
  14. 2.6 17 km NNE of Vieques, 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.