QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Carolina, PR

No earthquake was likely felt in Carolina in the 24 hours to 5:33 pm AST (21:33 UTC). The last one was M 4.1, 81 km (50 mi) SE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Carolina

This page: a magnitude 3.1 earthquake was recorded 45 km (28 mi) south-southeast of Carolina, PR, at 5:03 pm AST on 12 March 2023 (21:03 UTC), 11 km deep. 1 person has reported feeling it to USGS.

USGS: Puerto Rico region

53 km (33 mi) SE of San Juan, PR · 39 km (24 mi) ESE of Caguas, PR

5:03 pm AST, Mar 12, 2023 · · 11 km deep · released about 1,300 lb of TNT

Every earthquake near Carolina Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humacao Municipio 12 kmYabucoa Municipio 14 kmMaunabo Municipio 18 kmNaguabo Municipio 19 kmLas Piedras Municipio 22 kmCeiba Municipio 26 kmJuncos Municipio 28 kmPatillas Municipio 28 kmSan Lorenzo Municipio 29 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
5:03 pm AST on 12 March 2023 ()
Where
45 km (28 mi) south-southeast of Carolina, PR · earthquakes near Carolina
Magnitude
M 3.1 (md)
Depth
11 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Humacao Municipio, 12 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1271 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 40 km (25 mi) from the epicentre. In Carolina, 45 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: Humacao 16 km, intensity III · Emajagua 17 km, intensity II · Aguas Claras 24 km, intensity II · Esperanza 28 km, intensity II · Jagual 31 km, intensity II · Fajardo 32 km, intensity II · Isabel Segunda 32 km, intensity II · Luquillo 36 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 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× 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 in our catalogue was M 4.8 on 2021-10-08 — about 350 times the energy of this one.

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 18.0447, -65.7287. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humacao Municipio, PR 12 km (7 mi) NNW earthquakes near Humacao Municipio
Yabucoa Municipio, PR 14 km (9 mi) W earthquakes near Yabucoa Municipio
Maunabo Municipio, PR 18 km (11 mi) WSW earthquakes near Maunabo Municipio
Naguabo Municipio, PR 19 km (12 mi) N earthquakes near Naguabo Municipio
Las Piedras Municipio, PR 22 km (14 mi) NW earthquakes near Las Piedras Municipio
Ceiba Municipio, PR 26 km (16 mi) NNE earthquakes near Ceiba 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. 2.5 16 km SE of El Negro, Puerto Rico
  2. 2.3 6 km S of Punta Santiago, Puerto Rico
  3. 2.6 Puerto Rico region
  4. 2.6 2 km WNW of Bayamon, Puerto Rico
  5. 2.7 1 km W of Juncos, Puerto Rico
  6. 3.0 Puerto Rico region
  7. 3.0 Puerto Rico region
  8. 2.6 6 km S of Emajagua, Puerto Rico
  9. 2.7 5 km SSE of Esperanza, Puerto Rico
  10. 3.0 1 km E of Jagual, Puerto Rico
  11. 2.4 23 km SSE of Arroyo, Puerto Rico
  12. 2.7 2 km E of Santa Clara, Puerto Rico
  13. 3.0 1 km ENE of Bayamon, Puerto Rico
  14. 2.2 12 km SSE of Arroyo, Puerto Rico
  15. 2.8 24 km ESE of El Negro, 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.