Earthquake · reviewed by a seismologist
M 3.9md
Earthquake near Lamboglia, PR
No earthquake was likely felt in Lamboglia in the 24 hours to 1:02 pm AST (17:02 UTC). The last one was M 3.3, 47 km (29 mi) WSW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Lamboglia
This page: a magnitude 3.9 earthquake was recorded 7 km (4 mi) south-southwest of Lamboglia, PR, at 3:48 pm AST on 10 May 2018 (19:48 UTC), 13 km deep. 30 people have reported feeling it to USGS.
USGS: 6 km SSW of Lamboglia, Puerto Rico
53 km (33 mi) S of San Juan, PR · 34 km (21 mi) S of Caguas, PR
- When
- 3:48 pm AST on 10 May 2018 ()
- Where
- 7 km (4 mi) south-southwest of Lamboglia, PR · earthquakes near Lamboglia
- Magnitude
- M 3.9 (md)
- Depth
- 13 km below the surface
- Felt
- 30 reports · strongest reported intensity V
- Nearest
- Arroyo Municipio, 6 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2751 days ago
Earthquake alerts for Lamboglia, PR
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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 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 88 km (55 mi) from the epicentre. In Lamboglia, 7 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: Guayama 12 km, intensity III · Emajagua 16 km, intensity III · Jagual 26 km, intensity III · Cayey 26 km, intensity III · Humacao 31 km, intensity III · Caguas 34 km, intensity III · Sumidero 35 km, intensity III · Coamo 40 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.
- Northridge, California 1994 M 6.7 16,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 710× the energy of this one
- Magna, Utah 2020 M 5.7 500× the energy of this one
- This earthquake M 3.9 about 11 tons of TNT
- 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 4.6 on 2016-12-05 — about 11 times the energy of this one.
Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:
- 5.1 3 km W of Aguas Buenas, Puerto Rico · 39 km NNW 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 17.9283, -66.0126. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Arroyo Municipio, PR | 6 km (4 mi) | NNW | earthquakes near Arroyo Municipio |
| Patillas Municipio, PR | 8 km (5 mi) | NNE | earthquakes near Patillas Municipio |
| Guayama Municipio, PR | 14 km (9 mi) | WNW | earthquakes near Guayama Municipio |
| Maunabo Municipio, PR | 15 km (9 mi) | ENE | earthquakes near Maunabo Municipio |
| Yabucoa Municipio, PR | 22 km (14 mi) | NE | earthquakes near Yabucoa Municipio |
| Cayey Municipio, PR | 24 km (15 mi) | NW | earthquakes near Cayey Municipio |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
52 earthquakes have been recorded within 50 km since this one.
- 2.2 2 km NE of Jauca, Puerto Rico
- 1.7 0 km NNE of Las Ollas, Puerto Rico
- 2.0 3 km SW of Guaynabo, Puerto Rico
- 2.4 2 km SW of Sumidero, Puerto Rico
- 2.1 7 km SSW of Lamboglia, Puerto Rico
- 1.5 0 km NNW of Buena Vista, Puerto Rico
- 1.9 5 km ENE of G. L. Garcia, Puerto Rico
- 2.2 6 km SSW of Lamboglia, Puerto Rico
- 1.9 11 km SSE of Jauca, Puerto Rico
- 1.8 5 km SE of Arroyo, Puerto Rico
- 2.0 6 km NE of Comerío, Puerto Rico
- 1.9 9 km S of Emajagua, Puerto Rico
- 2.0 4 km S of Arroyo, Puerto Rico
- 1.7 3 km ESE of G. L. Garcia, Puerto Rico
- 2.6 6 km NE of Comerío, 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.