QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Puerto Rico region

Yes. A magnitude 2.5 earthquake was recorded in the Puerto Rico region, 91 km (57 mi) NW of San Juan, PR, at 1:14 am AST on 21 October 2018 (05:14 UTC), 36 km deep.

91 km (57 mi) NW of San Juan, PR · 55 km (34 mi) N of Arecibo, PR

· 36 km deep · released about 150 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Barceloneta Municipio 55 kmHatillo Municipio 57 kmArecibo Municipio 57 kmCamuy Municipio 58 kmQuebradillas Municipio 58 kmManatí Municipio 60 kmIsabela Municipio 60 kmVega Baja Municipio 64 kmFlorida Municipio 66 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 2.5 (md)
Depth
36 km below the surface
Felt
no reports yet
Nearest
Barceloneta Municipio, 55 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2944 days ago

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

How big was it?

This earthquake released about 150 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 99,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 70,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.2× the energy of this one
  4. This earthquake M 2.5 about 150 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 3,100 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 18.9456, -66.7131. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 55 km (34 mi) SSE earthquakes near Barceloneta Municipio
Hatillo Municipio, PR 57 km (35 mi) S earthquakes near Hatillo Municipio
Arecibo Municipio, PR 57 km (35 mi) S earthquakes near Arecibo Municipio
Camuy Municipio, PR 58 km (36 mi) SSW earthquakes near Camuy Municipio
Quebradillas Municipio, PR 58 km (36 mi) SSW earthquakes near Quebradillas Municipio
Manatí Municipio, PR 60 km (37 mi) SSE earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.5 64 km N of Brenas, Puerto Rico
  2. 2.5 Puerto Rico region
  3. 2.3 72 km N of Brenas, Puerto Rico
  4. 3.3 69 km N of Brenas, Puerto Rico
  5. 2.8 76 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.8 69 km N of Brenas, Puerto Rico
  7. 2.8 57 km N of Brenas, Puerto Rico
  8. 2.7 63 km N of Brenas, Puerto Rico
  9. 2.6 72 km N of Brenas, Puerto Rico
  10. 2.3 Puerto Rico region
  11. 2.5 70 km N of Brenas, Puerto Rico
  12. 2.7 54 km N of Hatillo, Puerto Rico
  13. 2.4 21 km NNE of Arecibo, Puerto Rico
  14. 2.5 47 km N of Isabela, Puerto Rico
  15. 2.2 9 km NNW of Camuy, 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.