QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Añasco, PR

No earthquake was likely felt in Añasco in the 24 hours to 3:27 pm AST (19:27 UTC). The last one was M 3.0, 36 km (22 mi) SSE, at 5:47 pm AST on 7 November 2026, estimated intensity II (weak) in town. Every earthquake near Añasco

This page: a magnitude 2.1 earthquake was recorded in Añasco, PR, at 10:09 pm AST on 6 March 2018 (02:09 UTC), 16 km deep.

USGS: 1 km SE of Añasco, Puerto Rico

8 km (5 mi) N of Mayagüez, PR · 114 km (71 mi) W of San Juan, PR

10:09 pm AST, Mar 6, 2018 · · 16 km deep · released about 51 lb of TNT

Every earthquake near Añasco Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Añasco Municipio 1 kmAguada Municipio 13 kmMoca Municipio 13 kmRincón Municipio 14 kmHormigueros Municipio 16 kmLas Marías Municipio 17 kmSan Sebastián Municipio 18 kmSan Germán Municipio 21 kmAguadilla Municipio 23 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
10:09 pm AST on 6 March 2018 ()
Where
in Añasco, PR · earthquakes near Añasco
Magnitude
M 2.1 (md)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Añasco Municipio, 1 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3172 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 8 km (5 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: Espino, Las Marias, La Playa, Mayagüez, Luyando, Aguada.

How big was it?

This earthquake released about 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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 4.3 on 2017-10-14 — about 1,700 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 24 km NNW of San Antonio, Puerto Rico · 48 km N of this epicentre
  2. 6.4 32 km NW of Aguadilla, Puerto Rico · 46 km NW of this epicentre
  3. 6.3 6 km WNW of Aguadilla, Puerto Rico · 20 km NNW of this epicentre
  4. 6.1 15 km WNW of San Antonio, Puerto Rico · 33 km NNW of this epicentre
  5. 6.1 18 km NNW of San Antonio, Puerto Rico · 41 km N of this epicentre

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 18.2745, -67.1320. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Añasco Municipio, PR 1 km (1 mi) N earthquakes near Añasco Municipio
Aguada Municipio, PR 13 km (8 mi) NNW earthquakes near Aguada Municipio
Moca Municipio, PR 13 km (8 mi) NNE earthquakes near Moca Municipio
Rincón Municipio, PR 14 km (9 mi) WNW earthquakes near Rincón Municipio
Hormigueros Municipio, PR 16 km (10 mi) S earthquakes near Hormigueros Municipio
Las Marías Municipio, PR 17 km (11 mi) ESE earthquakes near Las Marías Municipio

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

Aftershocks so far

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

  1. 2.3 2 km ESE of Las Marías, Puerto Rico
  2. 1.6 1 km SSW of Magas Arriba, Puerto Rico
  3. 2.3 5 km SSW of La Parguera, Puerto Rico
  4. 2.6 3 km NNE of Espino, Puerto Rico
  5. 2.3 5 km W of Hormigueros, Puerto Rico
  6. 2.2 13 km SW of La Playa, Puerto Rico
  7. 1.9 1 km SE of Guayanilla, Puerto Rico
  8. 2.0 1 km NNE of Sabana Eneas, Puerto Rico
  9. 2.4 16 km N of Hatillo, Puerto Rico
  10. 2.1 8 km SSE of La Parguera, Puerto Rico
  11. 2.1 7 km SSE of Guánica, Puerto Rico
  12. 1.9 0 km W of Sabana Grande, Puerto Rico
  13. 2.6 19 km WSW of Stella, Puerto Rico
  14. 2.1 4 km ESE of Boquerón, Puerto Rico
  15. 2.0 6 km NW of Puerto Real, 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.