QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Emajagua, PR

No earthquake was likely felt in Emajagua in the 24 hours to 4:45 pm AST (20:45 UTC). The last one was M 2.2, 7 km (5 mi) ESE, at 2:59 pm AST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Emajagua

This page: a magnitude 3.1 earthquake was recorded 27 km (17 mi) southeast of Emajagua, PR, at 9:26 pm AST on 22 November 2020 (01:26 UTC), 8.0 km deep.

USGS: 27 km SE of Emajagua, Puerto Rico

75 km (47 mi) SSE of San Juan, PR · 58 km (36 mi) SE of Caguas, PR

9:26 pm AST, Nov 22, 2020 · · 8.0 km deep · released about 1,400 lb of TNT

Every earthquake near Emajagua Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Maunabo Municipio 28 kmYabucoa Municipio 31 kmPatillas Municipio 35 kmHumacao Municipio 36 kmArroyo Municipio 39 kmNaguabo Municipio 44 kmLas Piedras Municipio 44 kmVieques Municipio 45 kmSan Lorenzo Municipio 46 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
9:26 pm AST on 22 November 2020 ()
Where
27 km (17 mi) southeast of Emajagua, PR · earthquakes near Emajagua
Magnitude
M 3.1 (md)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 28 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2175 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 42 km (26 mi) from the epicentre. In Emajagua, 27 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.

Likely felt in: Emajagua 27 km, intensity II · Humacao 39 km, intensity II · Esperanza 40 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 240,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,700× the energy of this one
  4. This earthquake M 3.1 about 1,400 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.5× more

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 170 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 · 47 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 17.8196, -65.7105. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 28 km (17 mi) NW earthquakes near Maunabo Municipio
Yabucoa Municipio, PR 31 km (19 mi) NNW earthquakes near Yabucoa Municipio
Patillas Municipio, PR 35 km (22 mi) NW earthquakes near Patillas Municipio
Humacao Municipio, PR 36 km (22 mi) NNW earthquakes near Humacao Municipio
Arroyo Municipio, PR 39 km (24 mi) WNW earthquakes near Arroyo Municipio
Naguabo Municipio, PR 44 km (27 mi) N 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. 3.5 72 km SSE of Emajagua, Puerto Rico
  2. 2.7 23 km ESE of El Negro, Puerto Rico
  3. 2.8 11 km S of Emajagua, Puerto Rico
  4. 3.2 27 km S of Esperanza, Puerto Rico
  5. 3.0 29 km SE of Emajagua, Puerto Rico
  6. 3.0 3 km SSE of Lamboglia, Puerto Rico
  7. 3.0 19 km S of Esperanza, Puerto Rico
  8. 3.4 23 km SSE of Esperanza, Puerto Rico
  9. 3.0 11 km W of Esperanza, Puerto Rico
  10. 2.3 3 km NNE of Olimpo, Puerto Rico
  11. 2.8 6 km N of Martorell, Puerto Rico
  12. 3.0 54 km SE of Emajagua, Puerto Rico
  13. 1.6 8 km SSW of Arroyo, Puerto Rico
  14. 1.8 8 km S of Palo Seco, Puerto Rico
  15. 3.2 30 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.