QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near San Germán, PR

No earthquake was likely felt in San Germán in the 24 hours to 7:59 pm AST (23:59 UTC). The last one was M 2.1, 12 km (7 mi) SW, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near San Germán

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) east-northeast of San Germán, PR, at 1:12 am AST on 19 December 2018 (05:12 UTC), 11 km deep.

USGS: 3 km ENE of San Germán, Puerto Rico

43 km (27 mi) WNW of Ponce, PR · 18 km (11 mi) SE of Mayagüez, PR

1:12 am AST, Dec 19, 2018 · · 11 km deep · released about 13 lb of TNT

Every earthquake near San Germán Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Germán Municipio 3 kmSabana Grande Municipio 7 kmHormigueros Municipio 12 kmMaricao Municipio 13 kmLajas Municipio 13 kmLas Marías Municipio 16 kmYauco Municipio 17 kmGuánica Municipio 19 kmCabo Rojo 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
1:12 am AST on 19 December 2018 ()
Where
3 km (2 mi) east-northeast of San Germán, PR · earthquakes near San Germán
Magnitude
M 1.8 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
San Germán Municipio, 3 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2885 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 7 km (4 mi) from the epicentre. In San Germán, 3 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: San Germán 3 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 44 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 35 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 39 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 39 km WNW 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 18.0910, -67.0158. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Germán Municipio, PR 3 km (2 mi) NW earthquakes near San Germán Municipio
Sabana Grande Municipio, PR 7 km (5 mi) E earthquakes near Sabana Grande Municipio
Hormigueros Municipio, PR 12 km (7 mi) WNW earthquakes near Hormigueros Municipio
Maricao Municipio, PR 13 km (8 mi) NE earthquakes near Maricao Municipio
Lajas Municipio, PR 13 km (8 mi) SSW earthquakes near Lajas Municipio
Las Marías Municipio, PR 16 km (10 mi) NNE earthquakes near Las Marías 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. 1.9 0 km NNW of Puerto Real, Puerto Rico
  2. 1.8 7 km S of Tallaboa, Puerto Rico
  3. 2.2 9 km S of Tallaboa, Puerto Rico
  4. 2.3 8 km WSW of Mayagüez, Puerto Rico
  5. 2.3 7 km NNW of Puerto Real, Puerto Rico
  6. 1.9 3 km SW of Adjuntas, Puerto Rico
  7. 1.5 6 km NNE of Lluveras, Puerto Rico
  8. 2.6 7 km NNE of Lluveras, Puerto Rico
  9. 1.6 1 km E of Liborio Negron Torres, Puerto Rico
  10. 1.7 15 km SSE of Pole Ojea, Puerto Rico
  11. 1.8 13 km WNW of Puerto Real, Puerto Rico
  12. 1.8 8 km S of Tallaboa, Puerto Rico
  13. 1.8 11 km W of Adjuntas, Puerto Rico
  14. 1.6 3 km NNW of Isabela, Puerto Rico
  15. 1.8 5 km ESE of Maricao, 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.