QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Lamboglia, PR

No earthquake was likely felt in Lamboglia in the 24 hours to 4:35 pm AST (20:35 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 2.8 earthquake was recorded 15 km (9 mi) south-southeast of Lamboglia, PR, at 2:14 am AST on 27 March 2021 (06:14 UTC), 10 km deep.

USGS: 14 km SSE of Lamboglia, Puerto Rico

62 km (39 mi) SSE of San Juan, PR · 43 km (27 mi) SSE of Caguas, PR

2:14 am AST, Mar 27, 2021 · · 10 km deep · released about 510 lb of TNT

10 km30 km60 km120 km N Maunabo Municipio 16 kmPatillas Municipio 17 kmArroyo Municipio 17 kmYabucoa Municipio 24 kmGuayama Municipio 25 kmSan Lorenzo Municipio 33 kmHumacao Municipio 35 kmCayey Municipio 36 kmSalinas Municipio 37 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
2:14 am AST on 27 March 2021 ()
Where
15 km (9 mi) south-southeast of Lamboglia, PR · earthquakes near Lamboglia
Magnitude
M 2.8 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 16 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2056 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 26 km (16 mi) from the epicentre. In Lamboglia, 15 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 17 km, intensity II · Guayama 23 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 510 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 30,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 21,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.9× the energy of this one
  4. This earthquake M 2.8 about 510 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 470 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 · 49 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 17.8568, -65.9368. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 16 km (10 mi) NNE earthquakes near Maunabo Municipio
Patillas Municipio, PR 17 km (10 mi) NNW earthquakes near Patillas Municipio
Arroyo Municipio, PR 17 km (11 mi) NW earthquakes near Arroyo Municipio
Yabucoa Municipio, PR 24 km (15 mi) NNE earthquakes near Yabucoa Municipio
Guayama Municipio, PR 25 km (15 mi) WNW earthquakes near Guayama Municipio
San Lorenzo Municipio, PR 33 km (20 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

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

  1. 1.6 2 km SSE of Salinas, Puerto Rico
  2. 3.3 18 km S of Emajagua, Puerto Rico
  3. 3.1 12 km S of Central Aguirre, Puerto Rico
  4. 2.8 10 km S of Central Aguirre, Puerto Rico
  5. 2.5 3 km NE of Las Ochenta, Puerto Rico
  6. 3.1 24 km SE of El Negro, Puerto Rico
  7. 3.6 21 km ESE of Emajagua, Puerto Rico
  8. 2.5 2 km SSW of Salinas, Puerto Rico
  9. 3.1 3 km ESE of Salinas, Puerto Rico
  10. 3.4 4 km ESE of Salinas, Puerto Rico
  11. 3.4 3 km ESE of Salinas, Puerto Rico
  12. 3.3 1 km SW of Cayey, Puerto Rico
  13. 2.8 1 km SSW of Cayey, Puerto Rico
  14. 2.7 0 km NW of Aguas Buenas, Puerto Rico
  15. 2.5 1 km SE of Salinas, 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.