QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Cayey, PR

No earthquake was likely felt in Cayey in the 24 hours to 1:34 pm AST (17:34 UTC). The last one was M 3.3, 38 km (24 mi) SW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Cayey

This page: a magnitude 2.1 earthquake was recorded 4 km (3 mi) south-southeast of Cayey, PR, at 5:48 pm AST on 23 July 2017 (21:48 UTC), 14 km deep.

USGS: 4 km SSE of Cayey, Puerto Rico

38 km (23 mi) SSW of San Juan, PR · 21 km (13 mi) SW of Caguas, PR

5:48 pm AST, Jul 23, 2017 · · 14 km deep · released about 41 lb of TNT

Every earthquake near Cayey Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cayey Municipio 3 kmCidra Municipio 11 kmGuayama Municipio 12 kmAibonito Municipio 13 kmArroyo Municipio 17 kmSalinas Municipio 17 kmComerío Municipio 18 kmCaguas Municipio 18 kmPatillas Municipio 20 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
5:48 pm AST on 23 July 2017 ()
Where
4 km (3 mi) south-southeast of Cayey, PR · earthquakes near Cayey
Magnitude
M 2.1 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Cayey Municipio, 3 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3398 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 10 km (6 mi) from the epicentre. In Cayey, 4 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: Cayey 4 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 41 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 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 5,800 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 · 20 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 18.0776, -66.1523. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cayey Municipio, PR 3 km (2 mi) N earthquakes near Cayey Municipio
Cidra Municipio, PR 11 km (7 mi) N earthquakes near Cidra Municipio
Guayama Municipio, PR 12 km (7 mi) S earthquakes near Guayama Municipio
Aibonito Municipio, PR 13 km (8 mi) WNW earthquakes near Aibonito Municipio
Arroyo Municipio, PR 17 km (10 mi) SE earthquakes near Arroyo Municipio
Salinas Municipio, PR 17 km (10 mi) SW earthquakes near Salinas Municipio

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

Aftershocks so far

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

  1. 2.9 7 km S of Jauca, Puerto Rico
  2. 3.1 12 km S of Santa Isabel, Puerto Rico
  3. 3.1 Puerto Rico region
  4. 2.5 5 km E of Bayamon, Puerto Rico
  5. 3.1 1 km SW of Trujillo Alto, Puerto Rico
  6. 3.1 2 km ENE of Candelero Arriba, Puerto Rico
  7. 2.4 3 km SW of Santa Isabel, Puerto Rico
  8. 2.5 2 km ESE of Mariano Colón, Puerto Rico
  9. 2.6 1 km NW of Aguas Buenas, Puerto Rico
  10. 2.3 3 km NNW of Patillas, Puerto Rico
  11. 1.6 0 km ESE of Villalba, Puerto Rico
  12. 2.6 2 km NNW of El Negro, Puerto Rico
  13. 2.8 1 km NNE of Yabucoa, Puerto Rico
  14. 2.3 1 km ESE of Río Cañas Abajo, Puerto Rico
  15. 2.6 6 km NNW of Bairoa, 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.