QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Moca, PR

No earthquake was likely felt in Moca in the 24 hours to 8:30 pm AST (00:30 UTC). The last one was M 3.5, in Moca, at 12:03 am AST on 6 November 2026, estimated intensity II (weak) in town. Every earthquake near Moca

This page: a magnitude 2.4 earthquake was recorded 4 km (3 mi) south-southeast of Moca, PR, at 7:59 pm AST on 9 January 2021 (23:59 UTC), 11 km deep.

USGS: 4 km SSE of Moca, Puerto Rico

18 km (11 mi) NNE of Mayagüez, PR · 109 km (68 mi) W of San Juan, PR

7:59 pm AST, Jan 9, 2021 · · 11 km deep · released about 130 lb of TNT

Every earthquake near Moca Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Moca Municipio 3 kmAñasco Municipio 9 kmAguada Municipio 9 kmSan Sebastián Municipio 14 kmAguadilla Municipio 14 kmRincón Municipio 16 kmIsabela Municipio 17 kmLas Marías Municipio 19 kmQuebradillas Municipio 22 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
7:59 pm AST on 9 January 2021 ()
Where
4 km (3 mi) south-southeast of Moca, PR · earthquakes near Moca
Magnitude
M 2.4 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Moca Municipio, 3 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2044 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 mi) from the epicentre. In Moca, 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: Aguadilla 10 km, intensity II · Aguada 10 km, intensity II · San Sebastián 12 km, intensity II · Rafael Hernandez 13 km, intensity II · Rincón 16 km, intensity II · Isabela 18 km, intensity II · Mayagüez 18 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 130 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 120,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 83,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.4× the energy of this one
  4. This earthquake M 2.4 about 130 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 5.2 on 2020-01-15 — about 15,000 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 24 km NNW of San Antonio, Puerto Rico · 39 km NNW of this epicentre
  2. 6.4 32 km NW of Aguadilla, Puerto Rico · 42 km NW of this epicentre
  3. 6.3 6 km WNW of Aguadilla, Puerto Rico · 15 km NW of this epicentre
  4. 6.1 15 km WNW of San Antonio, Puerto Rico · 26 km NNW of this epicentre
  5. 6.1 18 km NNW of San Antonio, Puerto Rico · 32 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 18.3580, -67.0986. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Moca Municipio, PR 3 km (2 mi) NE earthquakes near Moca Municipio
Añasco Municipio, PR 9 km (5 mi) SSW earthquakes near Añasco Municipio
Aguada Municipio, PR 9 km (6 mi) WNW earthquakes near Aguada Municipio
San Sebastián Municipio, PR 14 km (9 mi) ESE earthquakes near San Sebastián Municipio
Aguadilla Municipio, PR 14 km (9 mi) NNW earthquakes near Aguadilla Municipio
Rincón Municipio, PR 16 km (10 mi) W earthquakes near Rincón 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. 1.6 5 km ESE of La Parguera, Puerto Rico
  2. 1.8 2 km W of Guánica, Puerto Rico
  3. 2.4 1 km SE of Guánica, Puerto Rico
  4. 1.7 0 km ESE of Maria Antonia, Puerto Rico
  5. 1.6 4 km WSW of Guánica, Puerto Rico
  6. 1.6 4 km WSW of Guánica, Puerto Rico
  7. 1.6 1 km S of Guánica, Puerto Rico
  8. 1.6 Puerto Rico region
  9. 1.5 7 km WSW of Fuig, Puerto Rico
  10. 1.8 5 km WSW of Fuig, Puerto Rico
  11. 1.6 7 km E of Pole Ojea, Puerto Rico
  12. 1.8 4 km WSW of Guánica, Puerto Rico
  13. 2.0 4 km SW of La Parguera, Puerto Rico
  14. 2.0 Puerto Rico region
  15. 1.7 4 km WSW of Guánica, 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.