QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9Md

Mona Passage

Yes. A magnitude 2.9 earthquake was recorded in Mona Passage, at 9:47 pm AST on 20 August 2016 (01:47 UTC), 15 km deep.

· 15 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 56 kmAguadilla Municipio 58 kmQuebradillas Municipio 59 kmCamuy Municipio 63 kmHatillo Municipio 65 kmMoca Municipio 68 kmAguada Municipio 70 kmArecibo Municipio 72 kmSan Sebastián Municipio 73 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 2.9 (Md)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 56 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3645 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 28 km (17 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.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 18.9864, -67.0260. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 56 km (35 mi) S earthquakes near Isabela Municipio
Aguadilla Municipio, PR 58 km (36 mi) SSW earthquakes near Aguadilla Municipio
Quebradillas Municipio, PR 59 km (37 mi) S earthquakes near Quebradillas Municipio
Camuy Municipio, PR 63 km (39 mi) SSE earthquakes near Camuy Municipio
Hatillo Municipio, PR 65 km (41 mi) SSE earthquakes near Hatillo Municipio
Moca Municipio, PR 68 km (42 mi) S earthquakes near Moca Municipio

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

Aftershocks so far

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

  1. 3.0 60 km N of Hatillo, Puerto Rico
  2. 3.1 23 km NNW of Camuy, Puerto Rico
  3. 2.9 58 km NNW of San Antonio, Puerto Rico
  4. 2.8 70 km N of Isabela, Puerto Rico
  5. 3.1 41 km NW of San Antonio, Puerto Rico
  6. 2.9 71 km N of Arecibo, Puerto Rico
  7. 2.4 17 km N of Camuy, Puerto Rico
  8. 3.1 55 km NNW of San Antonio, Puerto Rico
  9. 3.0 23 km N of Hatillo, Puerto Rico
  10. 2.9 60 km N of Hatillo, Puerto Rico
  11. 3.1 66 km N of San Antonio, Puerto Rico
  12. 2.7 49 km N of Carrizales, Puerto Rico
  13. 2.9 61 km N of Isabela, Puerto Rico
  14. 2.9 61 km N of Hatillo, Puerto Rico
  15. 2.5 30 km NNE of Arecibo, 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.