QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Guaynabo, PR

No earthquake was likely felt in Guaynabo in the 24 hours to 7:39 pm AST (23:39 UTC). The last one was M 4.1, 93 km (58 mi) ESE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Guaynabo

This page: a magnitude 1.5 earthquake was recorded 5 km (3 mi) south-southwest of Guaynabo, PR, at 7:37 pm AST on 8 January 2019 (23:37 UTC), 19 km deep.

USGS: 5 km SSW of Guaynabo, Puerto Rico

13 km (8 mi) SW of San Juan, PR · 8 km (5 mi) SSE of Bayamón, PR

7:37 pm AST, Jan 8, 2019 · · 19 km deep · released about 5.6 lb of TNT

Every earthquake near Guaynabo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guaynabo Municipio 4 kmBayamón Municipio 5 kmAguas Buenas Municipio 7 kmToa Alta Municipio 12 kmNaranjito Municipio 12 kmComerío Municipio 13 kmSan Juan Municipio 14 kmCataño Municipio 14 kmTrujillo Alto Municipio 14 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
7:37 pm AST on 8 January 2019 ()
Where
5 km (3 mi) south-southwest of Guaynabo, PR · earthquakes near Guaynabo
Magnitude
M 1.5 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Guaynabo Municipio, 4 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2864 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 Guaynabo, 5 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: Aguas Buenas, Bayamón, Pájaros, Sumidero, Naranjito, Santa Clara.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 2 earthquakes of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 6 km S of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 30 km NW 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 18.3166, -66.1393. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guaynabo Municipio, PR 4 km (3 mi) NE earthquakes near Guaynabo Municipio
Bayamón Municipio, PR 5 km (3 mi) NW earthquakes near Bayamón Municipio
Aguas Buenas Municipio, PR 7 km (4 mi) S earthquakes near Aguas Buenas Municipio
Toa Alta Municipio, PR 12 km (8 mi) WNW earthquakes near Toa Alta Municipio
Naranjito Municipio, PR 12 km (8 mi) WSW earthquakes near Naranjito Municipio
Comerío Municipio, PR 13 km (8 mi) SW earthquakes near Comerío Municipio

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

Aftershocks so far

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

  1. 2.5 1 km SSW of Bayamon, Puerto Rico
  2. 1.9 5 km SE of Arroyo, Puerto Rico
  3. 2.6 Puerto Rico region
  4. 1.7 1 km NW of Parcelas Peñuelas, Puerto Rico
  5. 2.0 9 km SE of Arroyo, Puerto Rico
  6. 1.8 1 km NW of Aguas Buenas, Puerto Rico
  7. 2.0 Puerto Rico region
  8. 2.9 3 km N of Naranjito, Puerto Rico
  9. 1.6 1 km ESE of Los Llanos, Puerto Rico
  10. 1.9 1 km W of Jauca, Puerto Rico
  11. 1.6 1 km NNW of Jayuya, Puerto Rico
  12. 2.1 9 km SSE of Arroyo, Puerto Rico
  13. 2.3 9 km SSE of Arroyo, Puerto Rico
  14. 2.1 5 km SSE of Arroyo, Puerto Rico
  15. 1.9 4 km N of Palmarejo, 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.