QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Caguas, PR

No earthquake was likely felt in Caguas in the 24 hours to 12:59 pm AST (16:59 UTC). The last one was M 4.1, 81 km (50 mi) ESE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Caguas

This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) south of Caguas, PR, at 12:16 am AST on 23 July 2018 (04:16 UTC), 12 km deep.

USGS: 4 km S of Caguas, Puerto Rico

in Caguas, PR

12:16 am AST, Jul 23, 2018 · · 12 km deep · released about 15 lb of TNT

Every earthquake near Caguas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Caguas Municipio 2 kmSan Lorenzo Municipio 9 kmAguas Buenas Municipio 11 kmCidra Municipio 12 kmGurabo Municipio 12 kmCayey Municipio 14 kmJuncos Municipio 16 kmTrujillo Alto Municipio 17 kmComerío 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
12:16 am AST on 23 July 2018 ()
Where
5 km (3 mi) south of Caguas, PR · earthquakes near Caguas
Magnitude
M 1.8 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Caguas Municipio, 2 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3033 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 6 km (4 mi) from the epicentre. In Caguas, 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.

Likely felt in: Caguas 5 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

The largest earthquake within 50 km since 2016 was M 4.6 on 2016-12-05 — about 16,000 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 · 12 km NW of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 46 km NW 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 18.1898, -66.0526. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Caguas Municipio, PR 2 km (1 mi) N earthquakes near Caguas Municipio
San Lorenzo Municipio, PR 9 km (6 mi) ESE earthquakes near San Lorenzo Municipio
Aguas Buenas Municipio, PR 11 km (7 mi) NW earthquakes near Aguas Buenas Municipio
Cidra Municipio, PR 12 km (7 mi) W earthquakes near Cidra Municipio
Gurabo Municipio, PR 12 km (7 mi) NE earthquakes near Gurabo Municipio
Cayey Municipio, PR 14 km (9 mi) SW earthquakes near Cayey Municipio

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

Aftershocks so far

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

  1. 3.1 4 km NNE of Bairoa, Puerto Rico
  2. 1.7 2 km SSE of Pájaros, Puerto Rico
  3. 1.6 4 km W of Central Aguirre, Puerto Rico
  4. 2.4 8 km NNE of Dorado, Puerto Rico
  5. 1.8 5 km SSW of Central Aguirre, Puerto Rico
  6. 2.4 4 km NNE of Guaynabo, Puerto Rico
  7. 1.9 1 km N of Las Ochenta, Puerto Rico
  8. 2.2 5 km ESE of G. L. Garcia, Puerto Rico
  9. 2.7 5 km ESE of San Juan, Puerto Rico
  10. 2.0 0 km NW of Playita Cortada, Puerto Rico
  11. 2.1 3 km ESE of Cayey, Puerto Rico
  12. 2.4 2 km SSE of Cidra, Puerto Rico
  13. 2.5 17 km SSE of Jobos, Puerto Rico
  14. 2.5 3 km WSW of Sumidero, Puerto Rico
  15. 1.5 3 km W of Palo Seco, 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.