QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Isabel Segunda, PR

No earthquake was likely felt in Isabel Segunda in the 24 hours to 5:56 pm AST (21:56 UTC). The last one was M 2.9, 26 km (16 mi) SSE, at 12:08 pm AST on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Isabel Segunda

This page: a magnitude 2.9 earthquake was recorded 41 km (26 mi) east-southeast of Isabel Segunda, PR, at 8:10 pm AST on 31 October 2018 (00:10 UTC), 13 km deep.

USGS: 41 km ESE of Esperanza, Puerto Rico

8:10 pm AST, Oct 31, 2018 · · 13 km deep · released about 610 lb of TNT

10 km30 km60 km120 km N Vieques Municipio 39 kmCulebra Municipio 47 kmCeiba Municipio 63 kmFajardo Municipio 70 kmNaguabo Municipio 72 kmHumacao Municipio 74 kmLuquillo Municipio 78 kmYabucoa Municipio 80 kmMaunabo Municipio 83 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
8:10 pm AST on 31 October 2018 ()
Where
41 km (26 mi) east-southeast of Isabel Segunda, PR · earthquakes near Isabel Segunda
Magnitude
M 2.9 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Vieques Municipio, 39 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2933 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 28 km (17 mi) from the epicentre. In Isabel Segunda, 41 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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

  1. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 41 km ENE 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 17.9443, -65.1171. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vieques Municipio, PR 39 km (24 mi) WNW earthquakes near Vieques Municipio
Culebra Municipio, PR 47 km (29 mi) NNW earthquakes near Culebra Municipio
Ceiba Municipio, PR 63 km (39 mi) WNW earthquakes near Ceiba Municipio
Fajardo Municipio, PR 70 km (43 mi) NW earthquakes near Fajardo Municipio
Naguabo Municipio, PR 72 km (45 mi) WNW earthquakes near Naguabo Municipio
Humacao Municipio, PR 74 km (46 mi) WNW earthquakes near Humacao Municipio

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

Aftershocks so far

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

  1. 1.9 16 km SSW of Esperanza, Puerto Rico
  2. 2.7 18 km SSE of Esperanza, Puerto Rico
  3. 3.1 23 km SSW of Cruz Bay, U.S. Virgin Islands
  4. 2.5 26 km SE of Esperanza, Puerto Rico
  5. 2.9 10 km SSE of Esperanza, Puerto Rico
  6. 2.4 18 km S of Esperanza, Puerto Rico
  7. 2.0 21 km S of Esperanza, Puerto Rico
  8. 2.2 33 km S of Charlotte Amalie, U.S. Virgin Islands
  9. 2.2 Virgin Islands
  10. 2.2 18 km SSW of Charlotte Amalie, U.S. Virgin Islands
  11. 2.3 18 km WNW of Saint Croix, U.S. Virgin Islands
  12. 1.9 24 km S of Esperanza, Puerto Rico
  13. 2.6 29 km ESE of Esperanza, Puerto Rico
  14. 2.3 44 km S of Esperanza, Puerto Rico
  15. 2.2 16 km S 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.