QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7md

Earthquake near Esperanza, PR

No earthquake was likely felt in Esperanza in the 24 hours to 1:00 pm AST (17:00 UTC). The last one was M 2.9, 23 km (14 mi) SE, at 12:08 pm AST on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Esperanza

This page: a magnitude 3.7 earthquake was recorded 10 km (6 mi) southwest of Esperanza, PR, at 9:07 pm AST on 29 March 2021 (01:07 UTC), 5.0 km deep. 38 people have reported feeling it to USGS.

USGS: 9 km SW of Esperanza, Puerto Rico

70 km (44 mi) SE of San Juan, PR · 58 km (36 mi) ESE of Caguas, PR

9:07 pm AST, Mar 29, 2021 · · 5.0 km deep · released about 4.7 tons of TNT

Every earthquake near Esperanza Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vieques Municipio 15 kmCeiba Municipio 27 kmHumacao Municipio 30 kmNaguabo Municipio 30 kmYabucoa Municipio 35 kmMaunabo Municipio 39 kmLas Piedras Municipio 40 kmFajardo Municipio 40 kmCulebra Municipio 41 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
9:07 pm AST on 29 March 2021 ()
Where
10 km (6 mi) southwest of Esperanza, PR · earthquakes near Esperanza
Magnitude
M 3.7 (md)
Depth
5.0 km below the surface
Felt
38 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Vieques Municipio, 15 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1982 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 73 km (45 mi) from the epicentre. In Esperanza, 10 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: Esperanza 10 km, intensity III · Isabel Segunda 16 km, intensity III · Aguas Claras 28 km, intensity III · Humacao 34 km, intensity II · Fajardo 35 km, intensity II · Emajagua 38 km, intensity II · Culebra 39 km, intensity II · Luquillo 43 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 4.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 36,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,100× the energy of this one
  4. This earthquake M 3.7 about 4.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 9.8× 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 4.6 on 2016-12-05 — about 26 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 18.0291, -65.5293. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vieques Municipio, PR 15 km (9 mi) NE earthquakes near Vieques Municipio
Ceiba Municipio, PR 27 km (17 mi) NNW earthquakes near Ceiba Municipio
Humacao Municipio, PR 30 km (18 mi) WNW earthquakes near Humacao Municipio
Naguabo Municipio, PR 30 km (18 mi) NW earthquakes near Naguabo Municipio
Yabucoa Municipio, PR 35 km (22 mi) W earthquakes near Yabucoa Municipio
Maunabo Municipio, PR 39 km (24 mi) W earthquakes near Maunabo Municipio

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

Aftershocks so far

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

  1. 2.9 13 km SE of Esperanza, Puerto Rico
  2. 2.8 17 km SSE of Esperanza, Puerto Rico
  3. 2.3 1 km WNW of Esperanza, Puerto Rico
  4. 2.5 22 km SSW of Esperanza, Puerto Rico
  5. 3.1 9 km WSW of Culebra, Puerto Rico
  6. 3.7 15 km SE of Esperanza, Puerto Rico
  7. 2.2 7 km SSE of Lamboglia, Puerto Rico
  8. 3.0 13 km SE of Esperanza, Puerto Rico
  9. 1.8 19 km SW of Esperanza, Puerto Rico
  10. 3.2 18 km SE of Esperanza, Puerto Rico
  11. 3.2 Puerto Rico region
  12. 2.7 8 km SE of Esperanza, Puerto Rico
  13. 2.5 23 km SW of Esperanza, Puerto Rico
  14. 2.1 7 km SE of Esperanza, Puerto Rico
  15. 2.3 13 km SSE of Esperanza, 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.