QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Isabela, PR

No earthquake was likely felt in Isabela in the 24 hours to 1:35 pm AST (17:35 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 3.0 earthquake was recorded 12 km (8 mi) north-northeast of Isabela, PR, at 11:21 pm AST on 23 July 2017 (03:21 UTC), 14 km deep. 1 person has reported feeling it to USGS.

USGS: 12 km NNE of Isabela, Puerto Rico

32 km (20 mi) WNW of Arecibo, PR · 100 km (62 mi) WNW of San Juan, PR

11:21 pm AST, Jul 23, 2017 · · 14 km deep · released about 890 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 14 kmQuebradillas Municipio 17 kmAguadilla Municipio 22 kmCamuy Municipio 22 kmMoca Municipio 27 kmHatillo Municipio 27 kmSan Sebastián Municipio 31 kmAguada Municipio 33 kmArecibo Municipio 38 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
11:21 pm AST on 23 July 2017 ()
Where
12 km (8 mi) north-northeast of Isabela, PR · earthquakes near Isabela
Magnitude
M 3.0 (md)
Depth
14 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Isabela Municipio, 14 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1557 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, people at rest would likely notice it out to about 33 km (21 mi) from the epicentre. In Isabela, 12 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.

Likely felt in: Isabela 12 km, intensity II · Quebradillas 16 km, intensity II · Rafael Hernandez 18 km, intensity II · Hatillo 22 km, intensity II · Aguadilla 27 km, intensity II · San Sebastián 30 km, intensity II · Arecibo 32 km, intensity II · Aguada 33 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 890 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 380,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 17,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 890 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 36 km NNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 23 km WNW of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 42 km W of this epicentre
  4. 6.3 6 km WNW of Aguadilla, Puerto Rico · 30 km SW of this epicentre
  5. 6.1 15 km WNW of San Antonio, Puerto Rico · 26 km WSW 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 18.6073, -66.9886. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 14 km (9 mi) S earthquakes near Isabela Municipio
Quebradillas Municipio, PR 17 km (11 mi) SSE earthquakes near Quebradillas Municipio
Aguadilla Municipio, PR 22 km (13 mi) SW earthquakes near Aguadilla Municipio
Camuy Municipio, PR 22 km (14 mi) SE earthquakes near Camuy Municipio
Moca Municipio, PR 27 km (17 mi) SSW earthquakes near Moca Municipio
Hatillo Municipio, PR 27 km (17 mi) SE earthquakes near Hatillo Municipio

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

Aftershocks so far

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

  1. 2.0 31 km NW of San Antonio, Puerto Rico
  2. 2.0 47 km N of Isabela, Puerto Rico
  3. 2.3 57 km N of Isabela, Puerto Rico
  4. 3.1 51 km N of Hatillo, Puerto Rico
  5. 3.4 3 km NNE of Las Marias, Puerto Rico
  6. 3.3 1 km SW of San Sebastián, Puerto Rico
  7. 2.1 2 km W of Las Marías, Puerto Rico
  8. 4.3 21 km NW of Rincón, Puerto Rico
  9. 3.6 57 km N of Isabela, Puerto Rico
  10. 2.6 55 km N of Isabela, Puerto Rico
  11. 2.6 47 km NNW of San Antonio, Puerto Rico
  12. 2.8 21 km NW of Rincón, Puerto Rico
  13. 1.9 2 km N of Juncal, Puerto Rico
  14. 2.5 33 km NNE of Isabela, Puerto Rico
  15. 2.9 36 km N 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.