QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Comerío, PR

No earthquake was likely felt in Comerío in the 24 hours to 5:35 pm AST (21:35 UTC). The last one was M 3.3, 44 km (27 mi) SSW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Comerío

This page: a magnitude 1.7 earthquake was recorded 5 km (3 mi) east of Comerío, PR, at 9:48 am AST on 4 December 2018 (13:48 UTC), 19 km deep.

USGS: 5 km E of Comerío, Puerto Rico

23 km (14 mi) SSW of San Juan, PR · 15 km (9 mi) W of Caguas, PR

9:48 am AST, Dec 4, 2018 · · 19 km deep · released about 11 lb of TNT

Every earthquake near Comerío Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Comerío Municipio 4 kmCidra Municipio 6 kmAguas Buenas Municipio 6 kmNaranjito Municipio 11 kmCaguas Municipio 14 kmBayamón Municipio 14 kmCayey Municipio 14 kmAibonito Municipio 14 kmBarranquitas Municipio 14 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
9:48 am AST on 4 December 2018 ()
Where
5 km (3 mi) east of Comerío, PR · earthquakes near Comerío
Magnitude
M 1.7 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Comerío Municipio, 4 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2899 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 Comerío, 5 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: Santa Clara, Sumidero, Cidra, Parcelas La Milagrosa, Aguas Buenas, Parcelas Nuevas.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 930,000× the energy of this one
  3. Around the size people start to feel M 3.0 83× the energy of this one
  4. This earthquake M 1.7 about 11 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 21,000 times the energy of this one.

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 · 6 km NE of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 35 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 18.2258, -66.1786. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Comerío Municipio, PR 4 km (3 mi) W earthquakes near Comerío Municipio
Cidra Municipio, PR 6 km (4 mi) SSE earthquakes near Cidra Municipio
Aguas Buenas Municipio, PR 6 km (4 mi) ENE earthquakes near Aguas Buenas Municipio
Naranjito Municipio, PR 11 km (7 mi) NW earthquakes near Naranjito Municipio
Caguas Municipio, PR 14 km (8 mi) E earthquakes near Caguas Municipio
Bayamón Municipio, PR 14 km (9 mi) N earthquakes near Bayamón Municipio

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

Aftershocks so far

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

  1. 1.8 1 km NNW of Sumidero, Puerto Rico
  2. 2.1 11 km N of Loíza, Puerto Rico
  3. 1.9 2 km SW of Las Ollas, Puerto Rico
  4. 2.6 14 km N of Brenas, Puerto Rico
  5. 1.8 1 km NW of H. Rivera Colon, Puerto Rico
  6. 1.6 3 km SE of Santa Isabel, Puerto Rico
  7. 2.9 2 km ESE of H. Rivera Colon, Puerto Rico
  8. 2.0 Puerto Rico region
  9. 1.6 4 km SSW of Playita Cortada, Puerto Rico
  10. 1.7 8 km S of Emajagua, Puerto Rico
  11. 2.5 9 km SSW of Arroyo, Puerto Rico
  12. 2.6 2 km ENE of Corozal, 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.