QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7Md

Earthquake near Humacao, PR

No earthquake was likely felt in Humacao in the 24 hours to 11:22 pm AST (03:22 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 2.7 earthquake was recorded 41 km (26 mi) south-southeast of Humacao, PR, at 2:07 pm AST on 30 September 2016 (18:07 UTC), 17 km deep.

USGS: 32 km SSW of Esperanza, Puerto Rico

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

2:07 pm AST, Sep 30, 2016 · · 17 km deep · released about 340 lb of TNT

Every earthquake near Humacao Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Maunabo Municipio 35 kmYabucoa Municipio 36 kmVieques Municipio 37 kmHumacao Municipio 38 kmNaguabo Municipio 43 kmPatillas Municipio 43 kmCeiba Municipio 46 kmLas Piedras Municipio 47 kmArroyo 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
2:07 pm AST on 30 September 2016 ()
Where
41 km (26 mi) south-southeast of Humacao, PR · earthquakes near Humacao
Magnitude
M 2.7 (Md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 35 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3599 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 19 km (12 mi) from the epicentre. In Humacao, 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 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 4.3 on 2016-09-02 — about 250 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 17.8407, -65.6115. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 35 km (22 mi) WNW earthquakes near Maunabo Municipio
Yabucoa Municipio, PR 36 km (22 mi) NW earthquakes near Yabucoa Municipio
Vieques Municipio, PR 37 km (23 mi) NNE earthquakes near Vieques Municipio
Humacao Municipio, PR 38 km (23 mi) NNW earthquakes near Humacao Municipio
Naguabo Municipio, PR 43 km (27 mi) NNW earthquakes near Naguabo Municipio
Patillas Municipio, PR 43 km (27 mi) WNW earthquakes near Patillas Municipio

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

Aftershocks so far

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

  1. 2.9 24 km SW of Esperanza, Puerto Rico
  2. 2.9 23 km SW of Esperanza, Puerto Rico
  3. 1.9 27 km SW of Esperanza, Puerto Rico
  4. 2.5 26 km SW of Esperanza, Puerto Rico
  5. 1.9 28 km SE of El Negro, Puerto Rico
  6. 2.3 28 km SE of El Negro, Puerto Rico
  7. 1.7 27 km SE of Emajagua, Puerto Rico
  8. 2.2 28 km SE of El Negro, Puerto Rico
  9. 2.1 26 km SE of El Negro, Puerto Rico
  10. 3.0 25 km SW of Esperanza, Puerto Rico
  11. 2.9 23 km SW of Esperanza, Puerto Rico
  12. 1.6 11 km E of El Negro, Puerto Rico
  13. 1.7 1 km E of Bajandas, Puerto Rico
  14. 2.7 25 km SW of Esperanza, Puerto Rico
  15. 4.0 24 km SW 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.