QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Arroyo, PR

No earthquake was likely felt in Arroyo in the 24 hours to 11:38 pm AST (03:38 UTC). The last one was M 3.3, 39 km (24 mi) WSW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Arroyo

This page: a magnitude 2.3 earthquake was recorded 12 km (7 mi) south of Arroyo, PR, at 3:19 am AST on 31 March 2024 (07:19 UTC), 13 km deep.

USGS: 11 km S of Arroyo, Puerto Rico

60 km (38 mi) S of San Juan, PR · 41 km (26 mi) S of Caguas, PR

3:19 am AST, Mar 31, 2024 · · 13 km deep · released about 91 lb of TNT

Every earthquake near Arroyo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Arroyo Municipio 13 kmGuayama Municipio 14 kmPatillas Municipio 18 kmSalinas Municipio 23 kmMaunabo Municipio 25 kmCayey Municipio 28 kmYabucoa Municipio 32 kmSan Lorenzo Municipio 34 kmSanta Isabel Municipio 34 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
3:19 am AST on 31 March 2024 ()
Where
12 km (7 mi) south of Arroyo, PR · earthquakes near Arroyo
Magnitude
M 2.3 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Arroyo Municipio, 13 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 956 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 15 km (9 mi) from the epicentre. In Arroyo, 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: Guayama 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 91 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 120,000× the energy of this one
  3. Around the size people start to feel M 3.0 10× the energy of this one
  4. This earthquake M 2.3 about 91 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 4.6 on 2016-12-05 — about 2,600 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 45 km N 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 17.8607, -66.0763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Arroyo Municipio, PR 13 km (8 mi) NNE earthquakes near Arroyo Municipio
Guayama Municipio, PR 14 km (9 mi) NNW earthquakes near Guayama Municipio
Patillas Municipio, PR 18 km (11 mi) NNE earthquakes near Patillas Municipio
Salinas Municipio, PR 23 km (14 mi) WNW earthquakes near Salinas Municipio
Maunabo Municipio, PR 25 km (15 mi) NE earthquakes near Maunabo Municipio
Cayey Municipio, PR 28 km (18 mi) NNW earthquakes near Cayey 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. 2.1 3 km SSW of Potala Pastillo, Puerto Rico
  2. 2.5 3 km SW of G. L. Garcia, Puerto Rico
  3. 2.4 11 km S of Salinas, Puerto Rico
  4. 2.6 4 km SE of Jauca, Puerto Rico
  5. 2.9 26 km SSE of Arroyo, Puerto Rico
  6. 2.5 11 km S of Salinas, Puerto Rico
  7. 2.8 2 km SE of Río Cañas Abajo, Puerto Rico
  8. 2.8 18 km SSE of Lamboglia, Puerto Rico
  9. 2.5 5 km SE of El Negro, Puerto Rico
  10. 1.6 2 km W of Mariano Colón, Puerto Rico
  11. 3.1 3 km NE of Martorell, Puerto Rico
  12. 2.3 0 km W of Santa Isabel, Puerto Rico
  13. 3.2 21 km SSE of Lamboglia, Puerto Rico
  14. 2.3 4 km S of Salinas, Puerto Rico
  15. 2.5 1 km SW of El Ojo, 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.