QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Jobos, PR

No earthquake was likely felt in Jobos in the 24 hours to 4:29 pm AST (20:29 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 3.1 earthquake was recorded 9 km (6 mi) south of Jobos, PR, at 2:21 am AST on 31 July 2022 (06:21 UTC), 1.1 km deep.

USGS: 9 km S of Jobos, Puerto Rico

60 km (37 mi) SSW of San Juan, PR · 43 km (26 mi) SSW of Caguas, PR

2:21 am AST, Jul 31, 2022 · · 1.1 km deep · released about 1,300 lb of TNT

Every earthquake near Jobos Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guayama Municipio 12 kmSalinas Municipio 14 kmArroyo Municipio 18 kmSanta Isabel Municipio 24 kmPatillas Municipio 25 kmCayey Municipio 26 kmAibonito Municipio 30 kmCoamo Municipio 32 kmMaunabo Municipio 33 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
2:21 am AST on 31 July 2022 ()
Where
9 km (6 mi) south of Jobos, PR · earthquakes near Jobos
Magnitude
M 3.1 (md)
Depth
1.1 km below the surface
Felt
no reports yet
Nearest
Guayama Municipio, 12 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1565 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 41 km (25 mi) from the epicentre. In Jobos, 9 km away, the estimate is intensity III (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: Guayama 14 km, intensity III · Santa Isabel 26 km, intensity II · Cayey 26 km, intensity II · Coamo 30 km, intensity II · Emajagua 34 km, intensity II · Río Cañas Abajo 35 km, intensity II · Jagual 37 km, intensity II · Sumidero 39 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,300 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 6.7 260,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,200× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 180 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 · 43 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 17.8742, -66.1805. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayama Municipio, PR 12 km (7 mi) NNE earthquakes near Guayama Municipio
Salinas Municipio, PR 14 km (9 mi) NW earthquakes near Salinas Municipio
Arroyo Municipio, PR 18 km (11 mi) NE earthquakes near Arroyo Municipio
Santa Isabel Municipio, PR 24 km (15 mi) WNW earthquakes near Santa Isabel Municipio
Patillas Municipio, PR 25 km (15 mi) NE earthquakes near Patillas Municipio
Cayey Municipio, PR 26 km (16 mi) N earthquakes near Cayey Municipio

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

Aftershocks so far

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

  1. 2.9 3 km SW of Potala Pastillo, Puerto Rico
  2. 3.0 5 km SSW of Potala Pastillo, Puerto Rico
  3. 2.2 4 km SSW of Capitanejo, Puerto Rico
  4. 3.0 5 km SW of Potala Pastillo, Puerto Rico
  5. 3.4 4 km SSW of Potala Pastillo, Puerto Rico
  6. 3.4 5 km SSW of Potala Pastillo, Puerto Rico
  7. 3.6 5 km E of Candelero Arriba, Puerto Rico
  8. 2.2 3 km N of Orocovis, Puerto Rico
  9. 2.3 2 km SE of Lamboglia, Puerto Rico
  10. 2.3 3 km ESE of Salinas, Puerto Rico
  11. 3.0 6 km SSW of Potala Pastillo, Puerto Rico
  12. 1.9 2 km SSE of Lamboglia, Puerto Rico
  13. 2.4 Puerto Rico region
  14. 2.2 5 km SSW of Potala Pastillo, Puerto Rico
  15. 3.0 3 km ESE of Cayey, 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.