QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Cidra, PR

No earthquake was likely felt in Cidra in the 24 hours to 5:58 pm AST (21:58 UTC). The last one was M 3.3, 44 km (27 mi) SW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Cidra

This page: a magnitude 2.4 earthquake was recorded 2 km (1 mi) south-southeast of Cidra, PR, at 11:49 pm AST on 14 September 2018 (03:49 UTC), 76 km deep.

USGS: 2 km SSE of Cidra, Puerto Rico

29 km (18 mi) SSW of San Juan, PR · 14 km (9 mi) SW of Caguas, PR

11:49 pm AST, Sep 14, 2018 · · 76 km deep · released about 120 lb of TNT

Every earthquake near Cidra Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cidra Municipio 2 kmCayey Municipio 6 kmComerío Municipio 10 kmAguas Buenas Municipio 11 kmCaguas Municipio 12 kmAibonito Municipio 12 kmBarranquitas Municipio 17 kmNaranjito Municipio 18 kmSan Lorenzo Municipio 19 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
11:49 pm AST on 14 September 2018 ()
Where
2 km (1 mi) south-southeast of Cidra, PR · earthquakes near Cidra
Magnitude
M 2.4 (md)
Depth
76 km below the surface
Felt
no reports yet
Nearest
Cidra Municipio, 2 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2980 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 Cidra, 2 km away, the estimate is intensity I (not felt). 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: Parcelas Nuevas, Parcelas La Milagrosa, Cayey, G. L. Garcia, Santa Clara, Sumidero.

How big was it?

This earthquake released about 120 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 89,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.9× the energy of this one
  4. This earthquake M 2.4 about 120 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 2,000 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 · 11 km N of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 43 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 18.1598, -66.1516. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cidra Municipio, PR 2 km (1 mi) NNW earthquakes near Cidra Municipio
Cayey Municipio, PR 6 km (4 mi) S earthquakes near Cayey Municipio
Comerío Municipio, PR 10 km (6 mi) NW earthquakes near Comerío Municipio
Aguas Buenas Municipio, PR 11 km (7 mi) NNE earthquakes near Aguas Buenas Municipio
Caguas Municipio, PR 12 km (7 mi) ENE earthquakes near Caguas Municipio
Aibonito Municipio, PR 12 km (8 mi) WSW earthquakes near Aibonito Municipio

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

Aftershocks so far

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

  1. 2.1 1 km SSE of G. L. Garcia, Puerto Rico
  2. 2.1 6 km NNW of Loíza, Puerto Rico
  3. 1.6 3 km NNW of Playita Cortada, Puerto Rico
  4. 2.5 11 km S of Emajagua, Puerto Rico
  5. 1.9 2 km S of Las Ochenta, Puerto Rico
  6. 2.4 5 km SSW of Central Aguirre, Puerto Rico
  7. 1.6 9 km W of Orocovis, Puerto Rico
  8. 1.5 1 km SE of Santa Isabel, Puerto Rico
  9. 1.7 0 km WNW of Mariano Colón, Puerto Rico
  10. 2.2 3 km SSW of Pastos, Puerto Rico
  11. 2.1 9 km N of Villalba, Puerto Rico
  12. 1.7 3 km ENE of Pastos, Puerto Rico
  13. 2.1 3 km SSW of Salinas, Puerto Rico
  14. 1.7 2 km S of Jauca, Puerto Rico
  15. 2.2 2 km SE of Cidra, 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.