QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Mona Passage

Yes. A magnitude 2.4 earthquake was recorded in Mona Passage, 17 km (11 mi) SSE of Mayagüez, PR, at 7:22 am AST on 21 October 2023 (11:22 UTC), 20 km deep.

17 km (11 mi) SSE of Mayagüez, PR · 116 km (72 mi) WSW of San Juan, PR

· 20 km deep · released about 100 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Germán Municipio 9 kmHormigueros Municipio 9 kmLajas Municipio 10 kmCabo Rojo Municipio 10 kmSabana Grande Municipio 17 kmGuánica Municipio 22 kmMaricao Municipio 22 kmLas Marías Municipio 24 kmYauco Municipio 26 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 2.4 (md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
San Germán Municipio, 9 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1117 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 6 km (4 mi) from the epicentre. 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: Palmarejo, Monte Grande, Lajas, Sabana Eneas, Cabo Rojo, San Germán.

How big was it?

This earthquake released about 100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 140,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 100,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.1× the energy of this one
  4. This earthquake M 2.4 about 100 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

The largest earthquake within 50 km in our catalogue was M 6.4 on 2020-01-07 — about 1,100,000 times the energy of this one.

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 18.0508, -67.1010. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Germán Municipio, PR 9 km (6 mi) NE earthquakes near San Germán Municipio
Hormigueros Municipio, PR 9 km (6 mi) N earthquakes near Hormigueros Municipio
Lajas Municipio, PR 10 km (6 mi) SE earthquakes near Lajas Municipio
Cabo Rojo Municipio, PR 10 km (6 mi) SW earthquakes near Cabo Rojo Municipio
Sabana Grande Municipio, PR 17 km (10 mi) ENE earthquakes near Sabana Grande Municipio
Guánica Municipio, PR 22 km (14 mi) ESE earthquakes near Guánica Municipio

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

Aftershocks so far

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

  1. 2.8 1 km ESE of Indios, Puerto Rico
  2. 2.3 2 km WSW of Indios, Puerto Rico
  3. 2.7 7 km SSW of Guánica, Puerto Rico
  4. 3.0 9 km SSW of Guánica, Puerto Rico
  5. 2.3 1 km ENE of Indios, Puerto Rico
  6. 2.1 1 km WSW of Guayanilla, Puerto Rico
  7. 2.6 2 km WSW of Guayanilla, Puerto Rico
  8. 2.3 4 km SE of Indios, Puerto Rico
  9. 2.2 3 km E of Maria Antonia, Puerto Rico
  10. 2.4 7 km NNE of Yauco, Puerto Rico
  11. 2.4 4 km SSE of Indios, Puerto Rico
  12. 2.3 1 km SE of Yauco, Puerto Rico
  13. 2.6 5 km SSE of Guánica, Puerto Rico
  14. 2.4 3 km NW of Palmarejo, Puerto Rico
  15. 2.6 5 km WSW of Fuig, 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.