QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

Earthquake near G. L. Garcia, PR

No earthquake was likely felt in G. L. Garcia in the 24 hours to 9:03 am AST (13:03 UTC). The last one was M 3.3, 44 km (27 mi) SW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near G. L. Garcia

This page: a magnitude 3.5 earthquake was recorded 5 km (3 mi) east-southeast of G. L. Garcia, PR, at 12:03 am AST on 28 December 2024 (04:03 UTC), 24 km deep. 14 people have reported feeling it to USGS.

USGS: 4 km ESE of G. L. Garcia, Puerto Rico

14 km (9 mi) SSW of Caguas, PR · 33 km (20 mi) S of San Juan, PR

12:03 am AST, Dec 28, 2024 · · 24 km deep · released about 2.3 tons of TNT

10 km30 km60 km120 km N Cayey Municipio 9 kmSan Lorenzo Municipio 10 kmCaguas Municipio 11 kmCidra Municipio 12 kmPatillas Municipio 15 kmArroyo Municipio 16 kmGuayama Municipio 17 kmAguas Buenas Municipio 18 kmGurabo Municipio 20 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
12:03 am AST on 28 December 2024 ()
Where
5 km (3 mi) east-southeast of G. L. Garcia, PR · earthquakes near G. L. Garcia
Magnitude
M 3.5 (md)
Depth
24 km below the surface
Felt
14 reports · strongest reported intensity IV
Nearest
Cayey Municipio, 9 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 613 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 56 km (35 mi) from the epicentre. In G. L. Garcia, 5 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: Jagual 9 km, intensity II · Cayey 11 km, intensity II · Sumidero 14 km, intensity II · Caguas 14 km, intensity II · Guayama 15 km, intensity II · Emajagua 23 km, intensity II · Humacao 26 km, intensity II · Trujillo Alto 28 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 72,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,300× the energy of this one
  4. This earthquake M 3.5 about 2.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.9× 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 51 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 · 18 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 18.1098, -66.0656. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cayey Municipio, PR 9 km (6 mi) W earthquakes near Cayey Municipio
San Lorenzo Municipio, PR 10 km (6 mi) ENE earthquakes near San Lorenzo Municipio
Caguas Municipio, PR 11 km (7 mi) N earthquakes near Caguas Municipio
Cidra Municipio, PR 12 km (8 mi) NW earthquakes near Cidra Municipio
Patillas Municipio, PR 15 km (9 mi) SE earthquakes near Patillas Municipio
Arroyo Municipio, PR 16 km (10 mi) S earthquakes near Arroyo Municipio

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

Aftershocks so far

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

  1. 2.4 4 km SW of Las Piedras, Puerto Rico
  2. 2.0 8 km SE of Jobos, Puerto Rico
  3. 2.3 8 km SSE of Jobos, Puerto Rico
  4. 3.1 2 km NW of Hato Candal, Puerto Rico
  5. 3.0 3 km NW of H. Rivera Colon, Puerto Rico
  6. 3.4 2 km N of Pueblito del Rio, Puerto Rico
  7. 1.6 2 km S of G. L. Garcia, Puerto Rico
  8. 2.2 1 km W of Naranjito, Puerto Rico
  9. 2.2 3 km ESE of G. L. Garcia, Puerto Rico
  10. 2.9 2 km NW of Orocovis, Puerto Rico
  11. 2.1 3 km WNW of Guayabal, Puerto Rico
  12. 2.4 4 km SW of Las Piedras, Puerto Rico
  13. 2.0 3 km W of Orocovis, Puerto Rico
  14. 2.2 4 km SSW of Las Piedras, Puerto Rico
  15. 2.1 4 km SSW of Las Piedras, 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.