QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Lamboglia, PR

No earthquake was likely felt in Lamboglia in the 24 hours to 1:01 pm AST (17:01 UTC). The last one was M 3.3, 47 km (29 mi) WSW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Lamboglia

This page: a magnitude 3.0 earthquake was recorded 4 km (2 mi) south-southeast of Lamboglia, PR, at 6:01 pm AST on 23 July 2021 (22:01 UTC), 32 km deep. 1 person has reported feeling it to USGS.

USGS: 3 km SSE of Lamboglia, Puerto Rico

51 km (32 mi) SSE of San Juan, PR · 32 km (20 mi) SSE of Caguas, PR

6:01 pm AST, Jul 23, 2021 · · 32 km deep · released about 1,100 lb of TNT

Every earthquake near Lamboglia Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Patillas Municipio 6 kmArroyo Municipio 8 kmMaunabo Municipio 9 kmYabucoa Municipio 17 kmGuayama Municipio 18 kmSan Lorenzo Municipio 22 kmCayey Municipio 26 kmHumacao Municipio 28 kmLas Piedras Municipio 28 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
6:01 pm AST on 23 July 2021 ()
Where
4 km (2 mi) south-southeast of Lamboglia, PR · earthquakes near Lamboglia
Magnitude
M 3.0 (md)
Depth
32 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Patillas Municipio, 6 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1866 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 21 km (13 mi) from the epicentre. In Lamboglia, 4 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 11 km, intensity II · Guayama 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 320,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 14,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 10,000× the energy of this one
  4. This earthquake M 3.0 about 1,100 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 230 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 · 38 km NNW 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 17.9525, -65.9688. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Patillas Municipio, PR 6 km (4 mi) NNW earthquakes near Patillas Municipio
Arroyo Municipio, PR 8 km (5 mi) WNW earthquakes near Arroyo Municipio
Maunabo Municipio, PR 9 km (6 mi) NE earthquakes near Maunabo Municipio
Yabucoa Municipio, PR 17 km (10 mi) NE earthquakes near Yabucoa Municipio
Guayama Municipio, PR 18 km (11 mi) W earthquakes near Guayama Municipio
San Lorenzo Municipio, PR 22 km (13 mi) N earthquakes near San Lorenzo Municipio

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

Aftershocks so far

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

  1. 3.3 1 km ESE of Guaynabo, Puerto Rico
  2. 2.1 4 km WNW of Coamo, Puerto Rico
  3. 2.7 6 km SSE of Salinas, Puerto Rico
  4. 2.6 6 km SSE of Salinas, Puerto Rico
  5. 2.2 6 km SSE of Salinas, Puerto Rico
  6. 2.3 6 km SSE of Salinas, Puerto Rico
  7. 2.5 4 km SSE of Salinas, Puerto Rico
  8. 3.0 28 km SW of Esperanza, Puerto Rico
  9. 2.2 2 km E of G. L. Garcia, Puerto Rico
  10. 2.4 23 km S of Arroyo, Puerto Rico
  11. 3.6 0 km W of Canovanas, Puerto Rico
  12. 3.5 10 km S of Central Aguirre, Puerto Rico
  13. 1.6 2 km SSE of Salinas, Puerto Rico
  14. 3.3 18 km S of Emajagua, Puerto Rico
  15. 3.1 12 km S of Central Aguirre, 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.