QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

54 km SE of Emajagua, Puerto Rico

Yes. A magnitude 3.0 earthquake was recorded 54 km SE of Emajagua, Puerto Rico, at 7:51 am AST on 11 May 2021 (11:51 UTC), 13 km deep.

· 13 km deep · released about 950 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Maunabo Municipio 55 kmYabucoa Municipio 58 kmVieques Municipio 60 kmPatillas Municipio 61 kmHumacao Municipio 63 kmArroyo Municipio 64 kmNaguabo Municipio 69 kmLas Piedras Municipio 71 kmGuayama Municipio 72 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 3.0 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 55 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2009 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 34 km (21 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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 4.6 on 2016-12-05 — about 250 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.3 68 km SSE of Emajagua, Puerto Rico · 27 km SSW 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 17.6070, -65.5806. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 55 km (34 mi) NW earthquakes near Maunabo Municipio
Yabucoa Municipio, PR 58 km (36 mi) NNW earthquakes near Yabucoa Municipio
Vieques Municipio, PR 60 km (37 mi) NNE earthquakes near Vieques Municipio
Patillas Municipio, PR 61 km (38 mi) NW earthquakes near Patillas Municipio
Humacao Municipio, PR 63 km (39 mi) NNW earthquakes near Humacao Municipio
Arroyo Municipio, PR 64 km (39 mi) NW earthquakes near Arroyo Municipio

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

Aftershocks so far

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

  1. 2.9 13 km S of Esperanza, Puerto Rico
  2. 2.4 15 km S of Esperanza, Puerto Rico
  3. 2.3 6 km S of Esperanza, Puerto Rico
  4. 3.5 18 km S of Esperanza, Puerto Rico
  5. 2.9 33 km SSW of Esperanza, Puerto Rico
  6. 2.3 10 km SW of Esperanza, Puerto Rico
  7. 2.9 25 km SE of Emajagua, Puerto Rico
  8. 3.5 14 km SSE of Lamboglia, Puerto Rico
  9. 2.8 17 km S of Lamboglia, Puerto Rico
  10. 3.0 28 km SE of El Negro, Puerto Rico
  11. 2.9 18 km SW of Esperanza, Puerto Rico
  12. 2.8 17 km SSE of Esperanza, Puerto Rico
  13. 3.0 54 km S of Emajagua, Puerto Rico
  14. 2.5 22 km SSW of Esperanza, Puerto Rico
  15. 3.7 15 km SE of Esperanza, 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.