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 9:16 am AST (13:16 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 9 km (6 mi) south-southeast of San Germán, PR, at 4:00 pm AST on 7 December 2020 (20:00 UTC), 11 km deep.

USGS: Puerto Rico region

42 km (26 mi) W of Ponce, PR · 26 km (16 mi) SSE of Mayagüez, PR

4:00 pm AST, Dec 7, 2020 · · 11 km deep · released about 15 lb of TNT

Every earthquake near San Germán Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lajas Municipio 3 kmGuánica Municipio 12 kmSan Germán Municipio 12 kmSabana Grande Municipio 12 kmCabo Rojo Municipio 17 kmHormigueros Municipio 18 kmYauco Municipio 20 kmMaricao Municipio 21 kmGuayanilla Municipio 24 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
4:00 pm AST on 7 December 2020 ()
Where
9 km (6 mi) south-southeast of San Germán, PR · earthquakes near San Germán
Magnitude
M 1.8 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Lajas Municipio, 3 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2166 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 8 km (5 mi) from the epicentre. In San Germán, 9 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.

Earthquakes near other towns within 30 km: La Parguera, Lajas, Palmarejo, Liborio Negron Torres, Sabana Grande, Fuig.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 in our catalogue was M 6.4 on 2020-01-07 — about 8,200,000 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 17.9996, -67.0206. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lajas Municipio, PR 3 km (2 mi) SW earthquakes near Lajas Municipio
Guánica Municipio, PR 12 km (7 mi) ESE earthquakes near Guánica Municipio
San Germán Municipio, PR 12 km (8 mi) N earthquakes near San Germán Municipio
Sabana Grande Municipio, PR 12 km (8 mi) NE earthquakes near Sabana Grande Municipio
Cabo Rojo Municipio, PR 17 km (11 mi) W earthquakes near Cabo Rojo Municipio
Hormigueros Municipio, PR 18 km (11 mi) NW earthquakes near Hormigueros Municipio

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

Aftershocks so far

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

  1. 2.9 3 km SSW of Guánica, Puerto Rico
  2. 3.0 5 km ESE of La Parguera, Puerto Rico
  3. 2.5 4 km SW of Indios, Puerto Rico
  4. 2.4 4 km SW of Guánica, Puerto Rico
  5. 2.4 3 km E of Magas Arriba, Puerto Rico
  6. 2.2 1 km ESE of Indios, Puerto Rico
  7. 2.5 21 km S of Guánica, Puerto Rico
  8. 2.3 4 km SW of Guánica, Puerto Rico
  9. 2.3 3 km SSW of Indios, Puerto Rico
  10. 2.6 3 km SSE of Guánica, Puerto Rico
  11. 2.4 9 km S of Guánica, Puerto Rico
  12. 2.3 8 km S of Indios, Puerto Rico
  13. 2.7 7 km S of Guánica, Puerto Rico
  14. 2.3 2 km NNW of Indios, Puerto Rico
  15. 2.1 4 km SW 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.