QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7Md

Earthquake near San Germán, PR

No earthquake was likely felt in San Germán in the 24 hours to 4:28 pm AST (20:28 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 1.7 earthquake was recorded 6 km (4 mi) north-northeast of San Germán, PR, at 11:33 am AST on 28 March 2017 (15:33 UTC), 23 km deep.

USGS: 6 km NNE of San Germán, Puerto Rico

14 km (9 mi) ESE of Mayagüez, PR · 106 km (66 mi) WSW of San Juan, PR

11:33 am AST, Mar 28, 2017 · · 23 km deep · released about 11 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 kmHormigueros Municipio 9 kmSabana Grande Municipio 10 kmMaricao Municipio 11 kmLas Marías Municipio 12 kmLajas Municipio 17 kmYauco Municipio 19 kmAñasco Municipio 20 kmCabo Rojo 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
11:33 am AST on 28 March 2017 ()
Where
6 km (4 mi) north-northeast of San Germán, PR · earthquakes near San Germán
Magnitude
M 1.7 (Md)
Depth
23 km below the surface
Felt
no reports yet
Nearest
San Germán Municipio, 3 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3515 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In San Germán, 6 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: Maricao, Sabana Eneas, Monte Grande, Sabana Grande, Lajas, Hormigueros.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 · 39 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 30 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 36 km W of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 36 km W 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 18.1345, -67.0302. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Germán Municipio, PR 3 km (2 mi) SSW earthquakes near San Germán Municipio
Hormigueros Municipio, PR 9 km (6 mi) W earthquakes near Hormigueros Municipio
Sabana Grande Municipio, PR 10 km (6 mi) ESE earthquakes near Sabana Grande Municipio
Maricao Municipio, PR 11 km (7 mi) ENE earthquakes near Maricao Municipio
Las Marías Municipio, PR 12 km (7 mi) NNE earthquakes near Las Marías Municipio
Lajas Municipio, PR 17 km (11 mi) S earthquakes near Lajas Municipio

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

Aftershocks so far

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

  1. 2.4 1 km W of Palmarejo, Puerto Rico
  2. 1.6 9 km S of La Parguera, Puerto Rico
  3. 1.9 4 km NNW of Puerto Real, Puerto Rico
  4. 2.7 1 km ENE of Mayagüez, Puerto Rico
  5. 2.0 2 km WSW of Sabana Grande, Puerto Rico
  6. 2.3 3 km SSE of La Parguera, Puerto Rico
  7. 1.9 9 km SW of La Parguera, Puerto Rico
  8. 2.3 9 km SW of Guánica, Puerto Rico
  9. 2.7 19 km SW of Stella, Puerto Rico
  10. 1.6 3 km SW of Mayagüez, Puerto Rico
  11. 2.3 1 km NW of Liborio Negron Torres, Puerto Rico
  12. 1.8 19 km S of Guánica, Puerto Rico
  13. 1.6 5 km WSW of La Parguera, Puerto Rico
  14. 2.1 1 km ESE of Mayagüez, Puerto Rico
  15. 2.0 4 km NW of Rincón, 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.