QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8Md

Earthquake near Cayey, PR

No earthquake was likely felt in Cayey in the 24 hours to 2:09 am AST (06:09 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 1.8 earthquake was recorded 3 km (2 mi) east-southeast of Cayey, PR, at 6:53 am AST on 5 December 2016 (10:53 UTC), 7.0 km deep.

USGS: 3 km ESE of Cayey, Puerto Rico

35 km (22 mi) SSW of San Juan, PR · 18 km (11 mi) SW of Caguas, PR

6:53 am AST, Dec 5, 2016 · · 7.0 km deep · released about 15 lb of TNT

Every earthquake near Cayey Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cayey Municipio 2 kmCidra Municipio 9 kmGuayama Municipio 14 kmAibonito Municipio 14 kmCaguas Municipio 16 kmComerío Municipio 17 kmArroyo Municipio 17 kmAguas Buenas Municipio 18 kmSan Lorenzo Municipio 18 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
6:53 am AST on 5 December 2016 ()
Where
3 km (2 mi) east-southeast of Cayey, PR · earthquakes near Cayey
Magnitude
M 1.8 (Md)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Cayey Municipio, 2 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3629 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 12 km (7 mi) from the epicentre. In Cayey, 3 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 3 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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

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 · 18 km N of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 50 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 18.0972, -66.1388. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cayey Municipio, PR 2 km (1 mi) WNW earthquakes near Cayey Municipio
Cidra Municipio, PR 9 km (6 mi) NNW earthquakes near Cidra Municipio
Guayama Municipio, PR 14 km (9 mi) S earthquakes near Guayama Municipio
Aibonito Municipio, PR 14 km (9 mi) WNW earthquakes near Aibonito Municipio
Caguas Municipio, PR 16 km (10 mi) NE earthquakes near Caguas Municipio
Comerío Municipio, PR 17 km (10 mi) NNW earthquakes near Comerío Municipio

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

Aftershocks so far

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

  1. 2.6 11 km S of Emajagua, Puerto Rico
  2. 2.4 0 km WNW of Mariano Colón, Puerto Rico
  3. 3.1 1 km WSW of Sabana, Puerto Rico
  4. 2.0 10 km S of Emajagua, Puerto Rico
  5. 1.9 10 km S of Emajagua, Puerto Rico
  6. 2.5 11 km S of Emajagua, Puerto Rico
  7. 2.6 9 km S of Emajagua, Puerto Rico
  8. 2.9 10 km S of Emajagua, Puerto Rico
  9. 2.6 10 km S of Emajagua, Puerto Rico
  10. 2.3 8 km SE of Emajagua, Puerto Rico
  11. 2.3 9 km S of Emajagua, Puerto Rico
  12. 2.4 8 km S of Emajagua, Puerto Rico
  13. 2.3 6 km S of Punta Santiago, Puerto Rico
  14. 2.7 9 km S of Emajagua, Puerto Rico
  15. 2.0 9 km S of Emajagua, 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.