QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

95 km NNE of Luquillo, Puerto Rico

Yes. A magnitude 3.1 earthquake was recorded 95 km NNE of Luquillo, Puerto Rico, at 4:19 am AST on 7 September 2019 (08:19 UTC), 11 km deep.

· 11 km deep · released about 1,200 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 90 kmCulebra Municipio 94 kmLuquillo Municipio 96 kmRío Grande Municipio 99 kmLoíza Municipio 101 kmCeiba Municipio 105 kmCarolina Municipio 107 kmCanóvanas Municipio 108 kmSan Juan Municipio 112 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 3.1 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 90 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2538 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, people at rest would likely notice it out to about 39 km (24 mi) from the epicentre. 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 1,200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 280,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,800× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× 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 4.5 on 2018-03-06 — about 140 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 50 km ENE of this epicentre
  2. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 45 km ENE of this epicentre
  3. 5.1 122 km NNE of Vieques, Puerto Rico · 27 km N of this epicentre
  4. 5.1 92 km N of Suárez, Puerto Rico · 39 km WNW of this epicentre
  5. 5.0 109 km N of Charlotte Amalie, U.S. Virgin Islands · 40 km ENE 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 19.1680, -65.3606. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 90 km (56 mi) SSW earthquakes near Fajardo Municipio
Culebra Municipio, PR 94 km (58 mi) S earthquakes near Culebra Municipio
Luquillo Municipio, PR 96 km (60 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 99 km (62 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 101 km (63 mi) SW earthquakes near Loíza Municipio
Ceiba Municipio, PR 105 km (65 mi) SSW earthquakes near Ceiba Municipio

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

Aftershocks so far

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

  1. 2.9 99 km NNE of Vieques, Puerto Rico
  2. 3.3 Puerto Rico region
  3. 2.6 95 km N of Suárez, Puerto Rico
  4. 2.5 64 km N of Culebra, Puerto Rico
  5. 3.3 70 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.2 Puerto Rico region
  7. 3.1 62 km N of Charlotte Amalie, U.S. Virgin Islands
  8. 2.7 Puerto Rico region
  9. 3.0 120 km NNE of Vieques, Puerto Rico
  10. 2.2 62 km N of Culebra, Puerto Rico
  11. 2.5 66 km N of Culebra, Puerto Rico
  12. 2.8 62 km NNE of Vieques, Puerto Rico
  13. 2.4 52 km N of Culebra, Puerto Rico
  14. 2.9 86 km NNW of Charlotte Amalie, U.S. Virgin Islands
  15. 2.7 87 km N 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.