QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

6 km WSW of San Sebastián, Puerto Rico

· 25 km deep · released about 17 lb of TNT

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10 km30 km60 km120 km N San Sebastián Municipio 8 kmMoca Municipio 8 kmAñasco Municipio 10 kmLas Marías Municipio 12 kmAguada Municipio 17 kmLares Municipio 19 kmIsabela Municipio 19 kmMaricao Municipio 19 kmQuebradillas Municipio 21 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 1.8 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
San Sebastián Municipio, 8 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2978 days ago

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

How big was it?

This earthquake released about 17 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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.

Where

Epicentre 18.3146, -67.0423. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Sebastián Municipio, PR 8 km (5 mi) WSW of here earthquakes near San Sebastián Municipio
Moca Municipio, PR 8 km (5 mi) SSE of here earthquakes near Moca Municipio
Añasco Municipio, PR 10 km (6 mi) ENE of here earthquakes near Añasco Municipio
Las Marías Municipio, PR 12 km (7 mi) NW of here earthquakes near Las Marías Municipio
Aguada Municipio, PR 17 km (10 mi) ESE of here earthquakes near Aguada Municipio
Lares Municipio, PR 19 km (12 mi) WNW of here earthquakes near Lares Municipio

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

Aftershocks so far

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

  1. 2.3 1 km W of Hormigueros, Puerto Rico
  2. 2.2 11 km N of Arecibo, Puerto Rico
  3. 2.5 3 km NW of Las Marias, Puerto Rico
  4. 2.1 4 km SSW of San Sebastián, Puerto Rico
  5. 1.6 4 km SSW of Adjuntas, Puerto Rico
  6. 2.1 3 km N of Santo Domingo, Puerto Rico
  7. 2.0 1 km NNE of Boquerón, Puerto Rico
  8. 2.7 25 km NW of Aguadilla, Puerto Rico
  9. 2.0 2 km NW of Hormigueros, Puerto Rico
  10. 1.7 4 km ESE of Maricao, Puerto Rico
  11. 2.5 19 km N of Arecibo, Puerto Rico
  12. 1.9 4 km SE of Lajas, Puerto Rico
  13. 2.2 1 km SSE of Adjuntas, Puerto Rico
  14. 1.6 2 km SSW of Pole Ojea, Puerto Rico
  15. 1.6 3 km SW of Adjuntas, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.3 on 2017-10-14 — it released about 5,100 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.