QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Santa Barbara, PR

No earthquake was likely felt in Santa Barbara in the 24 hours to 1:01 pm AST (17:01 UTC). The last one was M 4.1, 78 km (49 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 Santa Barbara

This page: a magnitude 3.1 earthquake was recorded in Santa Barbara, PR, at 12:38 am AST on 23 May 2018 (04:38 UTC), 149 km deep.

USGS: 1 km SSW of Santa Barbara, Puerto Rico

15 km (9 mi) E of San Juan, PR · 7 km (4 mi) ESE of Carolina, PR

12:38 am AST, May 23, 2018 · · 149 km deep · released about 1,600 lb of TNT

Every earthquake near Santa Barbara Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Carolina Municipio 5 kmCanóvanas Municipio 7 kmLoíza Municipio 7 kmTrujillo Alto Municipio 10 kmRío Grande Municipio 13 kmGurabo Municipio 14 kmSan Juan Municipio 16 kmJuncos Municipio 18 kmGuaynabo Municipio 21 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
12:38 am AST on 23 May 2018 ()
Where
in Santa Barbara, PR · earthquakes near Santa Barbara
Magnitude
M 3.1 (md)
Depth
149 km below the surface
Felt
no reports yet
Nearest
Carolina Municipio, 5 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3004 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. 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: Canovanas, Carolina, San Isidro, Campo Rico, Loíza, La Dolores.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× more

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 2 earthquakes of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 26 km WSW of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 46 km WNW 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 18.3841, -65.9218. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Carolina Municipio, PR 5 km (3 mi) WNW earthquakes near Carolina Municipio
Canóvanas Municipio, PR 7 km (4 mi) SSE earthquakes near Canóvanas Municipio
Loíza Municipio, PR 7 km (4 mi) NNW earthquakes near Loíza Municipio
Trujillo Alto Municipio, PR 10 km (6 mi) WSW earthquakes near Trujillo Alto Municipio
Río Grande Municipio, PR 13 km (8 mi) E earthquakes near Río Grande Municipio
Gurabo Municipio, PR 14 km (9 mi) SSW earthquakes near Gurabo Municipio

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

Aftershocks so far

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

  1. 3.0 4 km ESE of Bayamon, Puerto Rico
  2. 2.6 3 km SSE of Guaynabo, Puerto Rico
  3. 2.8 3 km NNE of Naranjito, Puerto Rico
  4. 2.0 1 km NE of Sabana Seca, Puerto Rico
  5. 2.9 5 km SE of Cataño, Puerto Rico
  6. 2.1 7 km E of Naranjito, Puerto Rico
  7. 2.3 2 km SW of Bajandas, Puerto Rico
  8. 2.7 2 km E of La Fermina, Puerto Rico
  9. 1.9 6 km SSW of Emajagua, Puerto Rico
  10. 1.8 4 km S of Caguas, Puerto Rico
  11. 2.3 3 km ENE of Bayamón, Puerto Rico
  12. 2.9 8 km NNW of Dorado, Puerto Rico
  13. 2.8 31 km N of San Juan, Puerto Rico
  14. 2.0 1 km N of Bayamon, Puerto Rico
  15. 2.7 8 km S of Palo Seco, 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.