QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 12:08 pm AST (16:08 UTC). The last one was M 3.4, 49 km (31 mi) NW, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Arecibo

This page: a magnitude 2.1 earthquake was recorded 45 km (28 mi) north-northwest of Arecibo, PR, at 8:10 pm AST on 27 December 2019 (00:10 UTC), 36 km deep.

USGS: 42 km N of Hatillo, Puerto Rico

94 km (58 mi) WNW of San Juan, PR · 47 km (29 mi) N of Arecibo, PR

8:10 pm AST, Dec 27, 2019 · · 36 km deep · released about 49 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Quebradillas Municipio 47 kmCamuy Municipio 47 kmHatillo Municipio 48 kmIsabela Municipio 48 kmArecibo Municipio 50 kmBarceloneta Municipio 51 kmAguadilla Municipio 56 kmManatí Municipio 57 kmFlorida Municipio 61 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
8:10 pm AST on 27 December 2019 ()
Where
45 km (28 mi) north-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.1 (md)
Depth
36 km below the surface
Felt
no reports yet
Nearest
Quebradillas Municipio, 47 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2510 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 Arecibo, 45 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.

How big was it?

This earthquake released about 49 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 310,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 220,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 49 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 5.1 on 2019-09-24 — about 24,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 33 km W of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 45 km WSW of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 19 km N of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 47 km WSW of this epicentre
  5. 6.0 81 km N of Isabela, Puerto Rico · 42 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 18.8685, -66.8050. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Quebradillas Municipio, PR 47 km (29 mi) SSW earthquakes near Quebradillas Municipio
Camuy Municipio, PR 47 km (29 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 48 km (30 mi) S earthquakes near Hatillo Municipio
Isabela Municipio, PR 48 km (30 mi) SSW earthquakes near Isabela Municipio
Arecibo Municipio, PR 50 km (31 mi) SSE earthquakes near Arecibo Municipio
Barceloneta Municipio, PR 51 km (32 mi) SSE earthquakes near Barceloneta Municipio

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

Aftershocks so far

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

  1. 3.4 87 km N of Arecibo, Puerto Rico
  2. 3.4 69 km N of Hatillo, Puerto Rico
  3. 3.1 33 km N of Camuy, Puerto Rico
  4. 3.7 58 km N of San Antonio, Puerto Rico
  5. 3.4 69 km N of Hatillo, Puerto Rico
  6. 2.9 19 km N of Arecibo, Puerto Rico
  7. 3.0 46 km N of Carrizales, Puerto Rico
  8. 3.2 66 km N of Isabela, Puerto Rico
  9. 3.4 59 km N of Isabela, Puerto Rico
  10. 2.6 45 km N of Carrizales, Puerto Rico
  11. 2.5 19 km N of Isabela, Puerto Rico
  12. 3.4 69 km N of San Antonio, Puerto Rico
  13. 3.2 70 km N of San Antonio, Puerto Rico
  14. 2.5 63 km N of San Antonio, Puerto Rico
  15. 2.5 42 km NNW of San Antonio, 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.