QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Isabela, PR

No earthquake was likely felt in Isabela in the 24 hours to 4:06 am AST (08:06 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 2.1 earthquake was recorded 15 km (9 mi) north-northeast of Isabela, PR, at 2:18 pm AST on 24 October 2018 (18:18 UTC), 17 km deep.

USGS: 15 km NNE of Isabela, Puerto Rico

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

2:18 pm AST, Oct 24, 2018 · · 17 km deep · released about 44 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 17 kmQuebradillas Municipio 19 kmAguadilla Municipio 24 kmCamuy Municipio 24 kmHatillo Municipio 29 kmMoca Municipio 30 kmSan Sebastián Municipio 34 kmAguada Municipio 35 kmArecibo Municipio 39 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
2:18 pm AST on 24 October 2018 ()
Where
15 km (9 mi) north-northeast of Isabela, PR · earthquakes near Isabela
Magnitude
M 2.1 (md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 17 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2941 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 3 km (2 mi) from the epicentre. In Isabela, 15 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.

Earthquakes near other towns within 30 km: Quebradillas, Mora, Rafael Hernandez, Camuy, Cacao, Aceitunas.

How big was it?

This earthquake released about 44 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 1,900 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 34 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. 6.4 61 km N of Hatillo, Puerto Rico · 49 km NNE of this epicentre
  5. 6.3 6 km WNW of Aguadilla, Puerto Rico · 32 km SW 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 18.6321, -66.9858. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 17 km (10 mi) S earthquakes near Isabela Municipio
Quebradillas Municipio, PR 19 km (12 mi) SSE earthquakes near Quebradillas Municipio
Aguadilla Municipio, PR 24 km (15 mi) SW earthquakes near Aguadilla Municipio
Camuy Municipio, PR 24 km (15 mi) SSE earthquakes near Camuy Municipio
Hatillo Municipio, PR 29 km (18 mi) SE earthquakes near Hatillo Municipio
Moca Municipio, PR 30 km (19 mi) SSW earthquakes near Moca Municipio

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

Aftershocks so far

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

  1. 2.5 38 km WNW of San Antonio, Puerto Rico
  2. 2.2 9 km NNW of Camuy, Puerto Rico
  3. 2.4 15 km N of Carrizales, Puerto Rico
  4. 2.8 43 km NNW of San Antonio, Puerto Rico
  5. 1.8 7 km WNW of Maricao, Puerto Rico
  6. 2.1 19 km NNW of Camuy, Puerto Rico
  7. 1.8 1 km NNW of Mayagüez, Puerto Rico
  8. 2.4 20 km N of Carrizales, Puerto Rico
  9. 2.0 8 km SW of Las Marías, Puerto Rico
  10. 2.5 18 km NNW of Tierras Nuevas Poniente, Puerto Rico
  11. 2.8 46 km NNW of San Antonio, Puerto Rico
  12. 2.4 6 km SSE of Lares, Puerto Rico
  13. 2.8 50 km NNW of San Antonio, Puerto Rico
  14. 2.4 4 km S of La Playa, Puerto Rico
  15. 3.0 44 km NW of San Antonio, 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.