QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Magas Arriba, PR

No earthquake was likely felt in Magas Arriba in the 24 hours to 10:48 am AST (14:48 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 2.7 earthquake was recorded 2 km (1 mi) northeast of Magas Arriba, PR, at 9:01 pm AST on 4 July 2021 (01:01 UTC), 12 km deep. 1 person has reported feeling it to USGS.

USGS: 2 km NE of Magas Arriba, Puerto Rico

14 km (9 mi) WNW of Ponce, PR

9:01 pm AST, Jul 4, 2021 · · 12 km deep · released about 340 lb of TNT

Every earthquake near Magas Arriba Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Peñuelas Municipio 3 kmGuayanilla Municipio 6 kmYauco Municipio 13 kmPonce Municipio 16 kmAdjuntas Municipio 17 kmGuánica Municipio 20 kmSabana Grande Municipio 21 kmMaricao Municipio 25 kmJayuya Municipio 27 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
9:01 pm AST on 4 July 2021 ()
Where
2 km (1 mi) northeast of Magas Arriba, PR · earthquakes near Magas Arriba
Magnitude
M 2.7 (md)
Depth
12 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Peñuelas Municipio, 3 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1555 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 22 km (14 mi) from the epicentre. In Magas Arriba, 2 km away, the estimate is intensity III (weak). 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 2 km, intensity III · Guayanilla 4 km, intensity III · Tallaboa 6 km, intensity III · Tallaboa Alta 6 km, intensity III · Yauco 10 km, intensity II · Ponce 14 km, intensity II · Adjuntas 15 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 since 2016 was M 6.4 on 2020-01-07 — about 350,000 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 18.0315, -66.7533. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Peñuelas Municipio, PR 3 km (2 mi) ESE earthquakes near Peñuelas Municipio
Guayanilla Municipio, PR 6 km (3 mi) WSW earthquakes near Guayanilla Municipio
Yauco Municipio, PR 13 km (8 mi) WNW earthquakes near Yauco Municipio
Ponce Municipio, PR 16 km (10 mi) ESE earthquakes near Ponce Municipio
Adjuntas Municipio, PR 17 km (10 mi) N earthquakes near Adjuntas Municipio
Guánica Municipio, PR 20 km (13 mi) WSW 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. 2.7 5 km SE of Maria Antonia, Puerto Rico
  2. 2.1 2 km ESE of Palomas, Puerto Rico
  3. 2.1 4 km ESE of La Parguera, Puerto Rico
  4. 2.1 4 km SW of La Parguera, Puerto Rico
  5. 3.2 3 km NNW of La Parguera, Puerto Rico
  6. 1.8 1 km SE of Maria Antonia, Puerto Rico
  7. 1.8 18 km SSW of Guánica, Puerto Rico
  8. 2.2 4 km E of La Parguera, Puerto Rico
  9. 2.9 7 km SE of Maria Antonia, Puerto Rico
  10. 1.6 4 km SSW of La Parguera, Puerto Rico
  11. 3.0 3 km SW of Guánica, Puerto Rico
  12. 3.0 5 km S of Maria Antonia, Puerto Rico
  13. 2.1 7 km WSW of Guánica, Puerto Rico
  14. 1.6 4 km WSW of Fuig, Puerto Rico
  15. 2.5 6 km ENE of La Parguera, 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.