QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

Earthquake near Magas Arriba, PR

No earthquake was likely felt in Magas Arriba in the 24 hours to 10:49 am AST (14:49 UTC). The last one was M 2.1, 2 km (2 mi) W, at 4:39 pm AST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Magas Arriba

This page: a magnitude 3.9 earthquake was recorded in Magas Arriba, PR, at 2:34 pm AST on 16 January 2020 (18:34 UTC), 10 km deep. 3 people have reported feeling it to USGS.

USGS: 1 km SSE of Magas Arriba, Puerto Rico

15 km (9 mi) W of Ponce, PR

2:34 pm AST, Jan 16, 2020 · · 10 km deep · released about 11 tons of TNT

Every earthquake near Magas Arriba Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guayanilla Municipio 4 kmPeñuelas Municipio 5 kmYauco Municipio 14 kmPonce Municipio 17 kmGuánica Municipio 18 kmAdjuntas Municipio 20 kmSabana Grande Municipio 21 kmMaricao Municipio 26 kmJuana Díaz Municipio 29 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
2:34 pm AST on 16 January 2020 ()
Where
in Magas Arriba, PR · earthquakes near Magas Arriba
Magnitude
M 3.9 (ml)
Depth
10 km below the surface
Felt
3 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Guayanilla Municipio, 4 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2408 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 89 km (55 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.

Likely felt in: Magas Arriba in town, intensity IV · Guayanilla 3 km, intensity IV · Tallaboa 5 km, intensity IV · Tallaboa Alta 9 km, intensity III · Yauco 10 km, intensity III · Ponce 15 km, intensity III · Adjuntas 19 km, intensity III · Jayuya 30 km, intensity III. Estimated for each town centre; each link is that town's own record.

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.

For this area

The largest earthquake within 50 km since 2016 was M 6.4 on 2020-01-07 — about 5,600 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 18.0006, -66.7655. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayanilla Municipio, PR 4 km (2 mi) W earthquakes near Guayanilla Municipio
Peñuelas Municipio, PR 5 km (3 mi) NE earthquakes near Peñuelas Municipio
Yauco Municipio, PR 14 km (8 mi) NW earthquakes near Yauco Municipio
Ponce Municipio, PR 17 km (10 mi) E earthquakes near Ponce Municipio
Guánica Municipio, PR 18 km (11 mi) WSW earthquakes near Guánica Municipio
Adjuntas Municipio, PR 20 km (13 mi) N earthquakes near Adjuntas Municipio

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

Aftershocks so far

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

  1. 2.0 11 km S of Indios, Puerto Rico
  2. 2.9 10 km SSW of Ponce, Puerto Rico
  3. 2.7 0 km SW of Yauco, Puerto Rico
  4. 2.5 12 km SSE of Guánica, Puerto Rico
  5. 3.0 6 km SE of La Parguera, Puerto Rico
  6. 2.7 Puerto Rico region
  7. 2.6 3 km N of Yauco, Puerto Rico
  8. 2.7 6 km SE of La Parguera, Puerto Rico
  9. 2.5 11 km SSE of Maria Antonia, Puerto Rico
  10. 2.6 8 km SE of La Parguera, Puerto Rico
  11. 2.6 8 km S of Ponce, Puerto Rico
  12. 3.2 7 km ESE of La Parguera, Puerto Rico
  13. 2.8 9 km SSE of Maria Antonia, Puerto Rico
  14. 3.0 9 km S of Indios, Puerto Rico
  15. 2.6 4 km SSE of Tallaboa, 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.