QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

13 km ESE of El Negro, Puerto Rico

· 7.6 km deep · released about 1,600 lb of TNT

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10 km30 km60 km120 km N Yabucoa Municipio 16 kmMaunabo Municipio 17 kmHumacao Municipio 19 kmPatillas Municipio 26 kmNaguabo Municipio 27 kmLas Piedras Municipio 28 kmSan Lorenzo Municipio 32 kmArroyo Municipio 32 kmJuncos Municipio 33 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 3.1 (md)
Depth
7.6 km below the surface
Felt
4 reports · strongest reported intensity II
Nearest
Yabucoa Municipio, 16 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 985 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× 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 17.9705, -65.7418. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Yabucoa Municipio, PR 16 km (10 mi) SE of here earthquakes near Yabucoa Municipio
Maunabo Municipio, PR 17 km (10 mi) E of here earthquakes near Maunabo Municipio
Humacao Municipio, PR 19 km (12 mi) SSE of here earthquakes near Humacao Municipio
Patillas Municipio, PR 26 km (16 mi) E of here earthquakes near Patillas Municipio
Naguabo Municipio, PR 27 km (17 mi) S of here earthquakes near Naguabo Municipio
Las Piedras Municipio, PR 28 km (17 mi) SSE of here earthquakes near Las Piedras Municipio

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

Aftershocks so far

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

  1. 2.3 9 km SSW of Emajagua, Puerto Rico
  2. 2.1 12 km S of Arroyo, Puerto Rico
  3. 3.3 1 km WSW of Jagual, Puerto Rico
  4. 2.2 11 km S of Arroyo, Puerto Rico
  5. 2.4 12 km S of Arroyo, Puerto Rico
  6. 2.5 13 km S of Arroyo, Puerto Rico
  7. 2.2 5 km N of Patillas, 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 4.8 on 2021-10-08 — it released about 300 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.