QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Jobos, PR

No earthquake was likely felt in Jobos in the 24 hours to 4:30 pm AST (20:30 UTC). The last one was M 3.0, 28 km (18 mi) WSW, at 7:09 pm AST on 5 November 2026, estimated intensity II (weak) in town. Every earthquake near Jobos

This page: a magnitude 1.6 earthquake was recorded 6 km (4 mi) south-southeast of Jobos, PR, at 4:32 am AST on 18 April 2018 (08:32 UTC), 25 km deep.

USGS: 5 km SSE of Jobos, Puerto Rico

56 km (35 mi) S of San Juan, PR · 38 km (24 mi) SSW of Caguas, PR

4:32 am AST, Apr 18, 2018 · · 25 km deep · released about 6.4 lb of TNT

Every earthquake near Jobos Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guayama Municipio 8 kmArroyo Municipio 14 kmSalinas Municipio 14 kmPatillas Municipio 20 kmCayey Municipio 22 kmSanta Isabel Municipio 26 kmAibonito Municipio 28 kmMaunabo Municipio 29 kmCidra Municipio 30 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
4:32 am AST on 18 April 2018 ()
Where
6 km (4 mi) south-southeast of Jobos, PR · earthquakes near Jobos
Magnitude
M 1.6 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
Guayama Municipio, 8 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3129 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Jobos, 6 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.

Earthquakes near other towns within 30 km: Guayama, Central Aguirre, Coquí, Arroyo, Olimpo, Corazón.

How big was it?

This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.6 about 6.4 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 38,000 times the energy of this one.

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

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 39 km N 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 17.9053, -66.1486. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayama Municipio, PR 8 km (5 mi) N earthquakes near Guayama Municipio
Arroyo Municipio, PR 14 km (8 mi) ENE earthquakes near Arroyo Municipio
Salinas Municipio, PR 14 km (9 mi) WNW earthquakes near Salinas Municipio
Patillas Municipio, PR 20 km (13 mi) ENE earthquakes near Patillas Municipio
Cayey Municipio, PR 22 km (14 mi) N earthquakes near Cayey Municipio
Santa Isabel Municipio, PR 26 km (16 mi) WNW earthquakes near Santa Isabel Municipio

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

Aftershocks so far

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

  1. 2.6 3 km S of Palo Seco, Puerto Rico
  2. 2.7 8 km SSW of Emajagua, Puerto Rico
  3. 1.7 10 km S of Emajagua, Puerto Rico
  4. 2.2 7 km SE of Arroyo, Puerto Rico
  5. 2.1 7 km SE of Arroyo, Puerto Rico
  6. 1.6 2 km WSW of Coamo, Puerto Rico
  7. 1.8 5 km S of Palmas, Puerto Rico
  8. 2.9 3 km N of Palomas, Puerto Rico
  9. 2.7 6 km SE of Arroyo, Puerto Rico
  10. 1.8 6 km SSW of Lamboglia, Puerto Rico
  11. 1.9 3 km NNE of Río Cañas Abajo, Puerto Rico
  12. 1.6 2 km W of Potala Pastillo, Puerto Rico
  13. 2.4 8 km SSE of Jauca, Puerto Rico
  14. 1.8 2 km E of Aguilita, Puerto Rico
  15. 2.4 5 km SE of Arroyo, 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.