Earthquake · reviewed by a seismologist
M 4.0md
Earthquake near Guánica, PR
No earthquake was likely felt in Guánica in the 24 hours to 10:49 am AST (14:49 UTC). The last one was M 2.1, 13 km (8 mi) ENE, at 4:39 pm AST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Guánica
This page: a magnitude 4.0 earthquake was recorded 5 km (3 mi) south-southwest of Guánica, PR, at 7:37 am AST on 22 April 2023 (11:37 UTC), 13 km deep. 22 people have reported feeling it to USGS.
USGS: 5 km SSW of Guánica, Puerto Rico
34 km (21 mi) WSW of Ponce, PR
- When
- 7:37 am AST on 22 April 2023 ()
- Where
- 5 km (3 mi) south-southwest of Guánica, PR · earthquakes near Guánica
- Magnitude
- M 4.0 (md)
- Depth
- 13 km below the surface
- Felt
- 22 reports · strongest reported intensity IV
- Measured shaking
- intensity III (ShakeMap)
- USGS impact alert
- green
- Nearest
- Guánica Municipio, 2 km NE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1228 days ago
Earthquake alerts for Guánica, PR
Get a notification in this browser when USGS records an earthquake near Guánica, PR. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.
At this magnitude and depth, people at rest would likely notice it out to about 99 km (62 mi) from the epicentre. In Guánica, 5 km away, the estimate is intensity IV (light). 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: Yauco 14 km, intensity III · Guayanilla 18 km, intensity III · Magas Arriba 20 km, intensity III · San Germán 20 km, intensity III · Tallaboa 24 km, intensity III · Pole Ojea 27 km, intensity III · Tallaboa Alta 28 km, intensity III · Puerto Real 31 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 17 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 9,800× the energy of this one
- Mineral, Virginia 2011 M 5.8 440× the energy of this one
- Magna, Utah 2020 M 5.7 310× the energy of this one
- This earthquake M 4.0 about 17 tons of TNT
- Around the size people start to feel M 3.0 this one released 36× 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 3,500 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 17.9335, -66.9340. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Guánica Municipio, PR | 2 km (1 mi) | NE | earthquakes near Guánica Municipio |
| Lajas Municipio, PR | 12 km (8 mi) | WNW | earthquakes near Lajas Municipio |
| Guayanilla Municipio, PR | 16 km (10 mi) | ENE | earthquakes near Guayanilla Municipio |
| Sabana Grande Municipio, PR | 17 km (10 mi) | N | earthquakes near Sabana Grande Municipio |
| Yauco Municipio, PR | 19 km (12 mi) | NNE | earthquakes near Yauco Municipio |
| San Germán Municipio, PR | 22 km (14 mi) | NNW | earthquakes near San Germán Municipio |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.0 3 km N of La Parguera, Puerto Rico
- 2.0 3 km SSW of Liborio Negron Torres, Puerto Rico
- 2.1 2 km N of Guayanilla, Puerto Rico
- 1.9 3 km SW of Guánica, Puerto Rico
- 2.5 3 km SSW of Guánica, Puerto Rico
- 2.1 1 km NW of Magas Arriba, Puerto Rico
- 3.0 1 km NE of Guayanilla, Puerto Rico
- 2.1 10 km SSE of Maria Antonia, Puerto Rico
- 2.1 1 km NNW of Magas Arriba, Puerto Rico
- 2.8 1 km SE of Magas Arriba, Puerto Rico
- 1.7 0 km N of Sabana Eneas, Puerto Rico
- 2.3 3 km WSW of Indios, Puerto Rico
- 1.9 6 km WSW of Fuig, Puerto Rico
- 2.2 6 km WSW of Guánica, Puerto Rico
- 2.5 4 km SW of Fuig, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.