QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

61 km N of Isabela, Puerto Rico

Yes. A magnitude 2.8 earthquake was recorded 61 km N of Isabela, Puerto Rico, at 5:10 am AST on 22 May 2018 (09:10 UTC), 64 km deep.

· 64 km deep · released about 450 lb of TNT

10 km30 km60 km120 km N Isabela Municipio 64 kmQuebradillas Municipio 65 kmAguadilla Municipio 67 kmCamuy Municipio 68 kmHatillo Municipio 70 kmArecibo Municipio 74 kmBarceloneta Municipio 76 kmMoca Municipio 77 kmAguada Municipio 80 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
64 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 64 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3095 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 450 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 34,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 24,000× 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 450 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 4.7 on 2017-07-17 — about 660 times the energy of this one.

Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 25 km SW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 47 km SW of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 14 km E of this epicentre
  4. 6.0 93 km NNW of San Antonio, Puerto Rico · 47 km NW of this epicentre
  5. 6.0 81 km N of Isabela, Puerto Rico · 20 km N 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 19.0538, -66.9390. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 64 km (40 mi) S earthquakes near Isabela Municipio
Quebradillas Municipio, PR 65 km (41 mi) S earthquakes near Quebradillas Municipio
Aguadilla Municipio, PR 67 km (42 mi) SSW earthquakes near Aguadilla Municipio
Camuy Municipio, PR 68 km (42 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 70 km (43 mi) SSE earthquakes near Hatillo Municipio
Arecibo Municipio, PR 74 km (46 mi) SSE earthquakes near Arecibo Municipio

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

Aftershocks so far

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

  1. 2.8 41 km N of Carrizales, Puerto Rico
  2. 1.9 77 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.5 28 km NNW of Isabela, Puerto Rico
  4. 2.1 15 km N of Quebradillas, Puerto Rico
  5. 2.5 32 km NNW of San Antonio, Puerto Rico
  6. 2.6 41 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.5 78 km N of Arecibo, Puerto Rico
  8. 2.2 39 km NNW of San Antonio, Puerto Rico
  9. 3.0 63 km N of Hatillo, Puerto Rico
  10. 1.9 73 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 2.7 68 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 2.1 16 km N of Quebradillas, Puerto Rico
  13. 2.6 60 km N of Hatillo, Puerto Rico
  14. 2.8 56 km N of Hatillo, Puerto Rico
  15. 2.9 59 km N of Tierras Nuevas Poniente, 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.