QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

Earthquake near Sumidero, PR

No earthquake was likely felt in Sumidero in the 24 hours to 10:45 am AST (14:45 UTC). The last one was M 4.1, 89 km (55 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 Sumidero

This page: a magnitude 3.3 earthquake was recorded in Sumidero, PR, at 8:15 pm AST on 16 March 2018 (00:15 UTC), 122 km deep.

USGS: 1 km SE of Sumidero, Puerto Rico

8 km (5 mi) WSW of Caguas, PR

8:15 pm AST, Mar 16, 2018 · · 122 km deep · released about 1.3 tons of TNT

Every earthquake near Sumidero Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguas Buenas Municipio 6 kmCidra Municipio 6 kmCaguas Municipio 7 kmComerío Municipio 11 kmCayey Municipio 12 kmGuaynabo Municipio 15 kmGurabo Municipio 16 kmSan Lorenzo Municipio 16 kmBayamón Municipio 17 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
8:15 pm AST on 16 March 2018 ()
Where
in Sumidero, PR · earthquakes near Sumidero
Magnitude
M 3.3 (md)
Depth
122 km below the surface
Felt
no reports yet
Nearest
Aguas Buenas Municipio, 6 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3075 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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, Aguas Buenas, Cidra, Caguas, Parcelas La Milagrosa, G. L. Garcia.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,300× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.6× more

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 95 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 NNW of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 40 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 18.2083, -66.1133. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguas Buenas Municipio, PR 6 km (3 mi) NNW earthquakes near Aguas Buenas Municipio
Cidra Municipio, PR 6 km (4 mi) SW earthquakes near Cidra Municipio
Caguas Municipio, PR 7 km (4 mi) E earthquakes near Caguas Municipio
Comerío Municipio, PR 11 km (7 mi) W earthquakes near Comerío Municipio
Cayey Municipio, PR 12 km (8 mi) SSW earthquakes near Cayey Municipio
Guaynabo Municipio, PR 15 km (9 mi) N earthquakes near Guaynabo Municipio

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

Aftershocks so far

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

  1. 2.3 5 km SSW of Lamboglia, Puerto Rico
  2. 2.1 5 km SSW of Lamboglia, Puerto Rico
  3. 1.6 4 km N of Los Llanos, Puerto Rico
  4. 2.2 6 km SSW of Lamboglia, Puerto Rico
  5. 2.5 5 km S of Palmas, Puerto Rico
  6. 2.0 2 km N of Yaurel, Puerto Rico
  7. 1.7 3 km S of Palmas, Puerto Rico
  8. 3.0 7 km SSW of Lamboglia, Puerto Rico
  9. 3.9 6 km SSW of Lamboglia, Puerto Rico
  10. 3.0 6 km NW of Sabana, Puerto Rico
  11. 1.6 1 km SSW of Mariano Colón, Puerto Rico
  12. 2.4 13 km SSE of Arroyo, Puerto Rico
  13. 2.5 3 km NW of Barahona, Puerto Rico
  14. 2.5 13 km S of Jobos, Puerto Rico
  15. 2.5 1 km WNW of Campanilla, 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.