QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

118 km N of Culebra, Puerto Rico

Yes. A magnitude 2.8 earthquake was recorded 118 km N of Culebra, Puerto Rico, at 3:11 am AST on 19 August 2018 (07:11 UTC), 106 km deep.

· 106 km deep · released about 460 lb of TNT

10 km30 km60 km120 km N Fajardo Municipio 115 kmCulebra Municipio 116 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 2.8 (md)
Depth
106 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 115 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2937 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.

How big was it?

This earthquake released about 460 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 33,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 23,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.1× the energy of this one
  4. This earthquake M 2.8 about 460 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 4.5 on 2018-03-06 — about 370 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 35 km E of this epicentre
  2. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 40 km E of this epicentre
  3. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 33 km E of this epicentre
  4. 5.1 122 km NNE of Vieques, Puerto Rico · 7 km NW of this epicentre
  5. 5.1 92 km N of Suárez, Puerto Rico · 50 km WSW 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 19.3700, -65.2635. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 115 km (71 mi) SSW earthquakes near Fajardo Municipio
Culebra Municipio, PR 116 km (72 mi) S earthquakes near Culebra Municipio
Luquillo Municipio, PR 121 km (75 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 124 km (77 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 125 km (78 mi) SW earthquakes near Loíza Municipio
Carolina Municipio, PR 131 km (82 mi) SW earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 3.1 116 km NNE of Vieques, Puerto Rico
  2. 2.6 83 km N of Charlotte Amalie, U.S. Virgin Islands
  3. 3.1 108 km NNW of Charlotte Amalie, U.S. Virgin Islands
  4. 2.2 74 km NNW of Charlotte Amalie, U.S. Virgin Islands
  5. 3.4 128 km NNE of Vieques, Puerto Rico
  6. 2.5 110 km NNW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.3 69 km N of Culebra, Puerto Rico
  8. 3.2 125 km N of Culebra, Puerto Rico
  9. 3.4 135 km NNE of Suárez, Puerto Rico
  10. 2.6 151 km N of Charlotte Amalie, U.S. Virgin Islands
  11. 2.9 127 km NNE of Vieques, Puerto Rico
  12. 3.1 Puerto Rico region
  13. 3.6 119 km NNW of Charlotte Amalie, U.S. Virgin Islands
  14. 2.6 81 km N of Culebra, Puerto Rico
  15. 2.8 Puerto Rico region

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.