QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Río Grande, PR

No earthquake was likely felt in Río Grande in the 24 hours to 5:20 pm AST (21:20 UTC). The last one was M 4.1, 70 km (44 mi) SE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Río Grande

This page: a magnitude 2.7 earthquake was recorded 48 km (30 mi) north-northeast of Río Grande, PR, at 12:08 am AST on 16 December 2019 (04:08 UTC), 36 km deep.

USGS: 43 km NNE of Vieques, Puerto Rico

60 km (37 mi) NE of San Juan, PR · 54 km (33 mi) NE of Carolina, PR

12:08 am AST, Dec 16, 2019 · · 36 km deep · released about 360 lb of TNT

Every earthquake near Río Grande Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 45 kmLuquillo Municipio 46 kmRío Grande Municipio 48 kmLoíza Municipio 48 kmCarolina Municipio 54 kmCanóvanas Municipio 56 kmCeiba Municipio 59 kmSan Juan Municipio 59 kmTrujillo Alto Municipio 62 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
12:08 am AST on 16 December 2019 ()
Where
48 km (30 mi) north-northeast of Río Grande, PR · earthquakes near Río Grande
Magnitude
M 2.7 (md)
Depth
36 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 45 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2523 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. In Río Grande, 48 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.

How big was it?

This earthquake released about 360 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 42,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 30,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.6× the energy of this one
  4. This earthquake M 2.7 about 360 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 4.3 on 2016-09-04 — about 230 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.0 73 km NNE of Vieques, Puerto Rico · 29 km NE 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 18.7826, -65.6538. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 45 km (28 mi) S earthquakes near Fajardo Municipio
Luquillo Municipio, PR 46 km (29 mi) S earthquakes near Luquillo Municipio
Río Grande Municipio, PR 48 km (30 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 48 km (30 mi) SW earthquakes near Loíza Municipio
Carolina Municipio, PR 54 km (34 mi) SW earthquakes near Carolina Municipio
Canóvanas Municipio, PR 56 km (35 mi) SSW earthquakes near Canóvanas Municipio

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

Aftershocks so far

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

  1. 2.9 16 km NNE of Suárez, Puerto Rico
  2. 3.4 44 km N of Culebra, Puerto Rico
  3. 3.2 77 km NNE of Vieques, Puerto Rico
  4. 3.8 39 km N of Culebra, Puerto Rico
  5. 2.6 33 km N of San Juan, Puerto Rico
  6. 3.2 74 km NNE of Vieques, Puerto Rico
  7. 2.9 84 km NNE of Luquillo, Puerto Rico
  8. 3.1 80 km NNE of Luquillo, Puerto Rico
  9. 2.9 67 km NNE of Vieques, Puerto Rico
  10. 2.9 37 km NNE of Vieques, Puerto Rico
  11. 3.1 78 km NNE of Luquillo, Puerto Rico
  12. 2.0 Puerto Rico region
  13. 2.9 41 km NNE of Luquillo, Puerto Rico
  14. 3.1 55.7 km S of Culebra, Puerto Rico
  15. 2.9 57 km NNE of Culebra, 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.