QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9Ml

2 km NNW of Monte Grande, Puerto Rico

· 9.0 km deep · released about 11 tons of TNT

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10 km30 km60 km120 km N Hormigueros Municipio 3 kmSan Germán Municipio 8 kmCabo Rojo Municipio 14 kmLajas Municipio 16 kmSabana Grande Municipio 18 kmLas Marías Municipio 20 kmAñasco Municipio 20 kmMaricao Municipio 21 kmGuánica Municipio 27 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
Magnitude
M 3.9 (Ml)
Depth
9.0 km below the surface
Felt
44 reports · strongest reported intensity IV
Nearest
Hormigueros Municipio, 3 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1513 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 44 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× more

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.

Where

Epicentre 18.1049, -67.1165. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Hormigueros Municipio, PR 3 km (2 mi) S of here earthquakes near Hormigueros Municipio
San Germán Municipio, PR 8 km (5 mi) W of here earthquakes near San Germán Municipio
Cabo Rojo Municipio, PR 14 km (9 mi) NNE of here earthquakes near Cabo Rojo Municipio
Lajas Municipio, PR 16 km (10 mi) NNW of here earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 18 km (11 mi) W of here earthquakes near Sabana Grande Municipio
Las Marías Municipio, PR 20 km (12 mi) SW of here earthquakes near Las Marías Municipio

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

Aftershocks so far

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

  1. 2.1 3 km S of Guayanilla, Puerto Rico
  2. 2.2 4 km ESE of Hormigueros, Puerto Rico
  3. 2.0 12 km S of Pole Ojea, Puerto Rico
  4. 1.8 4 km WSW of Las Marías, Puerto Rico
  5. 2.0 4 km SSW of Luyando, Puerto Rico
  6. 2.6 19 km WSW of Stella, Puerto Rico
  7. 1.6 2 km ENE of Pole Ojea, Puerto Rico
  8. 2.2 13 km SW of La Playa, Puerto Rico
  9. 1.7 14 km SSW of La Parguera, Puerto Rico
  10. 1.7 5 km SW of Adjuntas, Puerto Rico
  11. 2.3 17 km SSW of Stella, Puerto Rico
  12. 2.3 23 km SSE of Maria Antonia, Puerto Rico
  13. 2.2 23 km S of Indios, Puerto Rico
  14. 2.0 1 km ENE of Pole Ojea, Puerto Rico
  15. 2.4 14 km NNW 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.