QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Arroyo, PR

No earthquake was likely felt in Arroyo in the 24 hours to 11:31 am AST (15:31 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 2.4 earthquake was recorded 13 km (8 mi) south-southeast of Arroyo, PR, at 1:38 am AST on 5 May 2018 (05:38 UTC), 53 km deep.

USGS: 13 km SSE of Arroyo, Puerto Rico

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

1:38 am AST, May 5, 2018 · · 53 km deep · released about 110 lb of TNT

Every earthquake near Arroyo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Arroyo Municipio 13 kmPatillas Municipio 15 kmMaunabo Municipio 19 kmGuayama Municipio 19 kmYabucoa Municipio 26 kmSalinas Municipio 30 kmCayey Municipio 31 kmSan Lorenzo Municipio 32 kmHumacao 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
1:38 am AST on 5 May 2018 ()
Where
13 km (8 mi) south-southeast of Arroyo, PR · earthquakes near Arroyo
Magnitude
M 2.4 (md)
Depth
53 km below the surface
Felt
no reports yet
Nearest
Arroyo Municipio, 13 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3112 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Arroyo, 13 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: Lamboglia, Palmas, Buena Vista, Patillas, Corazón, Palo Seco.

How big was it?

This earthquake released about 110 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 95,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.5× the energy of this one
  4. This earthquake M 2.4 about 110 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 2,100 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 · 46 km NNW 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 17.8631, -66.0008. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Arroyo Municipio, PR 13 km (8 mi) NNW earthquakes near Arroyo Municipio
Patillas Municipio, PR 15 km (10 mi) N earthquakes near Patillas Municipio
Maunabo Municipio, PR 19 km (12 mi) NE earthquakes near Maunabo Municipio
Guayama Municipio, PR 19 km (12 mi) NW earthquakes near Guayama Municipio
Yabucoa Municipio, PR 26 km (16 mi) NE earthquakes near Yabucoa Municipio
Salinas Municipio, PR 30 km (19 mi) WNW earthquakes near Salinas Municipio

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

Aftershocks so far

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

  1. 2.1 12 km S of Jobos, Puerto Rico
  2. 1.9 1 km NE of Jauca, Puerto Rico
  3. 2.2 2 km NE of Jauca, Puerto Rico
  4. 1.7 0 km NNE of Las Ollas, Puerto Rico
  5. 2.4 2 km SW of Sumidero, Puerto Rico
  6. 2.1 7 km SSW of Lamboglia, Puerto Rico
  7. 1.5 0 km NNW of Buena Vista, Puerto Rico
  8. 1.9 5 km ENE of G. L. Garcia, Puerto Rico
  9. 2.2 6 km SSW of Lamboglia, Puerto Rico
  10. 1.9 11 km SSE of Jauca, Puerto Rico
  11. 1.8 5 km SE of Arroyo, Puerto Rico
  12. 2.0 6 km NE of Comerío, Puerto Rico
  13. 1.9 9 km S of Emajagua, Puerto Rico
  14. 2.0 4 km S of Arroyo, Puerto Rico
  15. 1.7 3 km ESE of G. L. Garcia, 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.