QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Puerto Rico region

Yes. A magnitude 1.8 earthquake was recorded in the Puerto Rico region, at 4:49 am AST on 28 May 2017 (08:49 UTC), 10 km deep.

· 10 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 58 kmFajardo Municipio 73 kmVieques Municipio 84 kmLuquillo Municipio 85 kmCeiba Municipio 85 kmRío Grande Municipio 92 kmNaguabo Municipio 97 kmCanóvanas Municipio 103 kmLoíza Municipio 103 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 1.8 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 58 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3454 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 8 km (5 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 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 in our catalogue was M 4.3 on 2016-09-04 — about 6,700 times the energy of this one.

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 18.7716, -65.0280. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 58 km (36 mi) SSW earthquakes near Culebra Municipio
Fajardo Municipio, PR 73 km (45 mi) SW earthquakes near Fajardo Municipio
Vieques Municipio, PR 84 km (52 mi) SSW earthquakes near Vieques Municipio
Luquillo Municipio, PR 85 km (53 mi) WSW earthquakes near Luquillo Municipio
Ceiba Municipio, PR 85 km (53 mi) SW earthquakes near Ceiba Municipio
Río Grande Municipio, PR 92 km (57 mi) WSW earthquakes near Río Grande Municipio

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

Aftershocks so far

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

  1. 2.5 73 km NNW of Charlotte Amalie, U.S. Virgin Islands
  2. 2.7 75 km NNW of Charlotte Amalie, U.S. Virgin Islands
  3. 1.9 67 km NNW of Charlotte Amalie, U.S. Virgin Islands
  4. 2.2 Puerto Rico region
  5. 2.2 62 km NNW of Charlotte Amalie, U.S. Virgin Islands
  6. 1.8 75 km NNW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.2 65 km NNW of Charlotte Amalie, U.S. Virgin Islands
  8. 1.9 55 km NNE of Culebra, Puerto Rico
  9. 2.5 68 km NNW of Charlotte Amalie, U.S. Virgin Islands
  10. 2.8 75 km NNW of Charlotte Amalie, U.S. Virgin Islands
  11. 2.1 75 km NNW of Charlotte Amalie, U.S. Virgin Islands
  12. 2.7 72 km NNW of Charlotte Amalie, U.S. Virgin Islands
  13. 2.2 77 km NNW of Charlotte Amalie, U.S. Virgin Islands
  14. 2.1 74 km NNW of Charlotte Amalie, U.S. Virgin Islands
  15. 2.6 76 km N of Charlotte Amalie, U.S. Virgin Islands

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.