QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Humacao, PR

No earthquake was likely felt in Humacao in the 24 hours to 12:54 pm AST (16:54 UTC). The last one was M 4.1, 56 km (35 mi) ESE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Humacao

This page: a magnitude 2.9 earthquake was recorded 42 km (26 mi) south-southeast of Humacao, PR, at 4:18 am AST on 23 November 2020 (08:18 UTC), 5.0 km deep.

USGS: 33 km SE of Emajagua, Puerto Rico

79 km (49 mi) SE of San Juan, PR

4:18 am AST, Nov 23, 2020 · · 5.0 km deep · released about 610 lb of TNT

10 km30 km60 km120 km N Maunabo Municipio 34 kmYabucoa Municipio 36 kmHumacao Municipio 39 kmVieques Municipio 40 kmPatillas Municipio 43 kmNaguabo Municipio 45 kmArroyo Municipio 47 kmLas Piedras Municipio 48 kmCeiba Municipio 48 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
4:18 am AST on 23 November 2020 ()
Where
42 km (26 mi) south-southeast of Humacao, PR · earthquakes near Humacao
Magnitude
M 2.9 (md)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 34 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2179 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 30 km (19 mi) from the epicentre. In Humacao, 42 km away, the estimate is intensity II (weak). 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 610 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 25,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 610 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 390 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 · 48 km S 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 17.8193, -65.6323. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 34 km (21 mi) NW earthquakes near Maunabo Municipio
Yabucoa Municipio, PR 36 km (22 mi) NW earthquakes near Yabucoa Municipio
Humacao Municipio, PR 39 km (24 mi) NNW earthquakes near Humacao Municipio
Vieques Municipio, PR 40 km (25 mi) NNE earthquakes near Vieques Municipio
Patillas Municipio, PR 43 km (26 mi) WNW earthquakes near Patillas Municipio
Naguabo Municipio, PR 45 km (28 mi) NNW earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.2 1 km ESE of Emajagua, Puerto Rico
  2. 3.5 13 km SE of Esperanza, Puerto Rico
  3. 4.8 13 km SE of Esperanza, Puerto Rico
  4. 3.1 2 km SE of Emajagua, Puerto Rico
  5. 3.5 72 km SSE of Emajagua, Puerto Rico
  6. 2.7 23 km ESE of El Negro, Puerto Rico
  7. 2.8 11 km S of Emajagua, Puerto Rico
  8. 3.2 27 km S of Esperanza, Puerto Rico
  9. 3.0 29 km SE of Emajagua, Puerto Rico
  10. 3.0 3 km SSE of Lamboglia, Puerto Rico
  11. 3.0 19 km S of Esperanza, Puerto Rico
  12. 3.4 23 km SSE of Esperanza, Puerto Rico
  13. 3.0 11 km W of Esperanza, Puerto Rico
  14. 2.8 6 km N of Martorell, Puerto Rico
  15. 3.0 54 km SE of Emajagua, 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.