QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

60 km N of San Antonio, Puerto Rico

Yes. A magnitude 2.4 earthquake was recorded 60 km N of San Antonio, Puerto Rico, at 1:56 am AST on 23 December 2019 (05:56 UTC), 75 km deep.

· 75 km deep · released about 120 lb of TNT

10 km30 km60 km120 km N Aguadilla Municipio 61 kmIsabela Municipio 63 kmQuebradillas Municipio 68 kmCamuy Municipio 73 kmAguada Municipio 73 kmMoca Municipio 73 kmHatillo Municipio 77 kmRincón Municipio 78 kmSan Sebastián Municipio 81 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
Magnitude
M 2.4 (md)
Depth
75 km below the surface
Felt
no reports yet
Nearest
Aguadilla Municipio, 61 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2515 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. 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 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 5.8 120,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 86,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.7× 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 6.0 on 2019-09-24 — about 240,000 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 15 km SSE of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 37 km S of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 38 km E of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 44 km S of this epicentre
  5. 6.0 93 km NNW of San Antonio, Puerto Rico · 34 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 19.0321, -67.1725. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguadilla Municipio, PR 61 km (38 mi) S earthquakes near Aguadilla Municipio
Isabela Municipio, PR 63 km (39 mi) SSE earthquakes near Isabela Municipio
Quebradillas Municipio, PR 68 km (42 mi) SSE earthquakes near Quebradillas Municipio
Camuy Municipio, PR 73 km (45 mi) SSE earthquakes near Camuy Municipio
Aguada Municipio, PR 73 km (45 mi) S earthquakes near Aguada Municipio
Moca Municipio, PR 73 km (46 mi) S earthquakes near Moca Municipio

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

Aftershocks so far

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

  1. 2.9 97 km NNW of San Antonio, Puerto Rico
  2. 2.7 98 km N of Isabela, Puerto Rico
  3. 2.7 102 km NNW of San Antonio, Puerto Rico
  4. 2.6 70 km N of Isabela, Puerto Rico
  5. 3.1 76 km N of San Antonio, Puerto Rico
  6. 2.1 42 km N of Hatillo, Puerto Rico
  7. 2.0 40 km N of Hatillo, Puerto Rico
  8. 2.9 75 km N of San Antonio, Puerto Rico
  9. 3.1 66 km N of San Antonio, Puerto Rico
  10. 3.0 100 km NNW of San Antonio, Puerto Rico
  11. 3.0 83 km NNW of San Antonio, Puerto Rico
  12. 3.2 91 km NNW of San Antonio, Puerto Rico
  13. 3.0 83 km NNW of San Antonio, Puerto Rico
  14. 2.6 85 km NNW of San Antonio, Puerto Rico
  15. 3.0 82 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.