QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Isabela, PR

No earthquake was likely felt in Isabela in the 24 hours to 9:54 pm AST (01:54 UTC). The last one was M 3.4, 31 km (19 mi) N, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Isabela

This page: a magnitude 2.5 earthquake was recorded 28 km (18 mi) north-northwest of Isabela, PR, at 10:44 pm AST on 28 June 2018 (02:44 UTC), 57 km deep. 1 person has reported feeling it to USGS.

USGS: 28 km NNW of Isabela, Puerto Rico

49 km (30 mi) NW of Arecibo, PR · 114 km (71 mi) WNW of San Juan, PR

10:44 pm AST, Jun 28, 2018 · · 57 km deep · released about 190 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 30 kmAguadilla Municipio 31 kmQuebradillas Municipio 35 kmCamuy Municipio 41 kmMoca Municipio 42 kmAguada Municipio 43 kmHatillo Municipio 45 kmSan Sebastián Municipio 48 kmRincón 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
10:44 pm AST on 28 June 2018 ()
Where
28 km (18 mi) north-northwest of Isabela, PR · earthquakes near Isabela
Magnitude
M 2.5 (md)
Depth
57 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Isabela Municipio, 30 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3058 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 Isabela, 28 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 190 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 80,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 57,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.1× the energy of this one
  4. This earthquake M 2.5 about 190 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 4.3 on 2017-10-14 — about 450 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 18 km NNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 13 km WSW of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 36 km WSW of this epicentre
  4. 6.4 61 km N of Hatillo, Puerto Rico · 43 km NE of this epicentre
  5. 6.3 6 km WNW of Aguadilla, Puerto Rico · 37 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 18.7511, -67.0778. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 30 km (19 mi) SSE earthquakes near Isabela Municipio
Aguadilla Municipio, PR 31 km (19 mi) SSW earthquakes near Aguadilla Municipio
Quebradillas Municipio, PR 35 km (22 mi) SSE earthquakes near Quebradillas Municipio
Camuy Municipio, PR 41 km (25 mi) SSE earthquakes near Camuy Municipio
Moca Municipio, PR 42 km (26 mi) S earthquakes near Moca Municipio
Aguada Municipio, PR 43 km (27 mi) SSW earthquakes near Aguada Municipio

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

Aftershocks so far

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

  1. 2.3 18 km NNE of Arecibo, Puerto Rico
  2. 2.5 9 km NNE of Isabela, Puerto Rico
  3. 2.5 12 km N of Hatillo, Puerto Rico
  4. 2.3 9 km N of Carrizales, Puerto Rico
  5. 1.8 6 km WSW of San Sebastián, Puerto Rico
  6. 2.9 54 km N of Hatillo, Puerto Rico
  7. 2.8 45 km N of Carrizales, Puerto Rico
  8. 2.4 17 km N of Arecibo, Puerto Rico
  9. 2.9 50 km NW of San Antonio, Puerto Rico
  10. 2.8 16 km NW of Rincón, Puerto Rico
  11. 3.2 Puerto Rico region
  12. 2.4 5 km NW of Rincón, Puerto Rico
  13. 2.2 29 km NNE of Arecibo, Puerto Rico
  14. 2.5 11 km N of Carrizales, Puerto Rico
  15. 2.2 15 km NNE 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.